Commit Graph

50 Commits

Author SHA1 Message Date
Tim Allen 7af270aa59 Update to v103r09 release.
byuu says:

Changelog:

  - gba/apu: fixed wave RAM nibble ordering (fixes audio in Castlevania,
    PocketNES)
  - emulator: restructured video information to just a single
    videoResolution() → VideoResolution function
      - returns "projected size" (between 160x144 and 320x240)
      - "internal buffer size" (up to 1280x480)
      - returns aspect correction multiplier that is to be applied to
        the width field
          - the value could be < 1.0 to handle systems with taller
            pixels; although higan doesn't emulate such a system
  - tomoko: all calculations for scaling and overscan masking are done
    by the GUI now
  - tomoko: aspect correction can be enabled in either windowed or
    fullscreen mode separately; moved to Video settings panel
  - tomoko: video scaling multipliers (against 320x240) can now me
    modified from the default (2,3,4) via the configuration file
      - use this as a really barebones way of supporting high DPI
        monitors; although the GUI elements won't scale nicely
      - if you set a value less than two, or greater than your
        resolution divided by 320x240, it's your own fault when things
        blow up. I'm not babysitting anyone with advanced config-file
        only options.
  - tomoko: added new adaptive windowed mode
      - when enabled, the window will shrink to eliminate any black
        borders when loading a game or changing video settings. The
        window will not reposition itself.
  - tomoko: added new adaptive fullscreen mode
      - when enabled, the integral scaling will be disabled for
        fullscreen mode, forcing the video to fill at least one
        direction of the video monitor completely.

I expect we will be bikeshedding for the next month on how to describe
the new video options, where they should appear in the GUI, changes
people want, etc ... but suffice to say, I'm happy with the
functionality, so I don't intend to make changes to -what- things do,
but I will entertain better ways to name things.
2017-07-06 18:29:12 +10:00
Tim Allen 191a71b291 Update to v103r08 release.
byuu says:

Changelog:

  - emulator: improved aspect correction accuracy by using
    floating-point calculations
  - emulator: added videoCrop() function, extended videoSize() to take
    cropping parameters¹
  - tomoko: the overscan masking function will now actually resize the
    viewport²
  - gba/cpu: fixed two-cycle delay on triggering DMAs; not running DMAs
    when the CPU is stopped
  - md/vdp: center video when overscan is disabled
  - pce/vce: resize video output from 1140x240 to 1120x240
  - tomoko: resize window scaling from 326x240 to 320x240
  - tomoko: changed save slot naming and status bar messages to indicate
    quick states vs managed states
  - tomoko: added increment/decrement quick state hotkeys
  - tomoko: save/load quick state hotkeys now save to slots 1-5 instead
    of always to 0
  - tomoko: increased overscan range from 0-16 to 0-24 (in case you want
    to mask the Master System to 240x192)

¹: the idea here was to decouple raw pixels from overscan masking.
Overscan was actually horrifically broken before. The Famicom outputs at
256x240, the Super Famicom at 512x480, and the Mega Drive at 1280x480.
Before, a horizontal overscan mask of 8 would not reduce the Super
Famicom or Mega Drive by nearly as much as the Famicom. WIth the new
videoCrop() function, the internals of pixel size distortions can be
handled by each individual core.

²: furthermore, by taking optional cropping information in
videoSize(), games can scale even larger into the viewport window. So
for example, before the Super Famicom could only scale to 1536x1440. But
by cropping the vertical resolution by 6 (228p effectively, still more
than NTSC can even show), I can now scale to 1792x1596. And wiht aspect
correction, that becomes a perfect 8:7 ratio of 2048x1596, giving me
perfectly crisp pixels without linear interpolation being required.

Errata: for some reason, when I save a new managed state with the SFC
core, the default description is being set to a string of what looks to
be hex numbers. I found the cause ... I'll fix this in the next release.

Note: I'd also like to hide the "find codes..." button if cheats.bml
isn't present, as well as update the SMP TEST register comment from
smp/timing.cpp
2017-07-05 16:39:14 +10:00
Tim Allen 40802b0b9f Update to v103r05 release.
byuu says:

Changelog:

  - fc/controller: added ControllerPort class; removed Peripherals class
  - md/controller/gamepad: removed X,Y,Z buttons since this isn't a
    6-button controller
  - ms/controller: added ControllerPort class (not used in Game Gear
    mode); removed Peripherals class
  - pce/controller: added ControllerPort class; removed Peripherals
    class
  - processor/spc700: idle(address) is part of SMP class again, contains
    flag to detect mov (x)+ edge case
  - sfc/controller/super-scope,justifier: use CPU frequency instead of
    hard-coding NTSC frequency
  - sfc/cpu: move 4x8-bit SMP ports to SMP class
  - sfc/smp: move APU RAM to DSP class
  - sfc/smp: improved emulation of TEST registers bits 4-7 [information
    from nocash]
      - d4,d5 is RAM wait states (1,2,5,10)
      - d6,d7 is ROM/IO wait states (1,2,5,10)
  - sfc/smp: code cleanup to new style (order from lowest to highest
    bits; use .bit(s) functions)
  - sfc/smp: $00f8,$00f9 are P4/P5 auxiliary ports; named the registers
    better
2017-07-01 16:15:27 +10:00
Tim Allen ff3750de4f Update to v103r04 release.
byuu says:

Changelog:

  - fc/apu: $4003,$4007 writes initialize duty counter to 0 instead of 7
  - fc/apu: corrected duty table entries for use with decrementing duty
    counter
  - processor/spc700: emulated the behavior of cycle 3 of (x)+
    instructions to not read I/O registers
      - specifically, this prevents reads from $fd-ff from resetting the
        timers, as observed on real hardware
  - sfc/controller: added ControllerPort class to match Mega Drive
    design
  - sfc/expansion: added ExpansionPort class to match Mega Drive design
  - sfc/system: removed Peripherals class
  - sfc/system: changed `colorburst()` to `cpuFrequency()`; added
    `apuFrequency()`
  - sfc: replaced calls to `system.region == System::Region::*` with
    `Region::*()`
  - sfc/expansion: remove thread from scheduler when device is destroyed
  - sfc/smp: `{read,write}Port` now use a separate 4x8-bit buffer instead
    of underlying APU RAM [hex\_usr]
2017-06-30 14:17:23 +10:00
Tim Allen 78f341489e Update to v103r03 release.
byuu says:

Changelog:

  - md/psg: fixed output frequency rate regression from v103r02
  - processor/m68k: fixed calculations for ABCD, NBCD, SBCD [hex\_usr,
    SuperMikeMan]
  - processor/spc700: renamed abbreviated instructions to functional
    descriptions (eg `XCN` → `ExchangeNibble`)
  - processor/spc700: removed memory.cpp shorthand functions (fetch,
    load, store, pull, push)
  - processor/spc700: updated all instructions to follow cycle behavior
    as documented by Overload with a logic analyzer

Once again, the changes to the SPC700 core are really quite massive. And
this time it's not just cosmetic: the idle cycles have been updated to
pull from various memory addresses. This is why I removed the shorthand
functions -- so that I could handle the at-times very bizarre addresses
the SPC700 has on its address bus during its idle cycles.

There is one behavior Overload mentioned that I don't emulate ... one of
the cycles of the (X) transfer functions seems to not actually access
the $f0-ff internal SMP registers? I don't fully understand what
Overload is getting at, so I haven't tried to support it just yet.

Also, there are limits to logic analyzers. In many cases the same
address is read from twice consecutively. It is unclear which of the two
reads the SPC700 actually utilizes. I tried to choose the most logical
values (usually the first one), but ... I don't know that we'll be able
to figure this one out. It's going to be virtually impossible to test
this through software, because the PC can't really execute out of
registers that have side effects on reads.
2017-06-28 17:24:46 +10:00
Tim Allen 3517d5c4a4 Update to v103r02 release.
byuu says:

Changelog:

  - fc/apu: improved phase duty cycle emulation (mode 3 is 25% phase
    inverted; counter decrements)
  - md/apu: power/reset do not cancel 68K bus requests
  - md/apu: 68K is not granted bus access on Z80 power/reset
  - md/controller: replaced System::Peripherals with ControllerPort
    concept
  - md/controller: CTRL port is now read-write, maintains value across
    controller changes (and soon, soft resets)
  - md/psg: PSG sampling rate unintentionally modified¹
  - processor/spc700: improve cycle timing of (indirect),y instructions
    [Overload]
  - processor/spc700: idle() cycles actually read from the program
    counter; much like the 6502 [Overload]
      - some of the idle() cycles should read from other addresses; this
        still needs to be supported
  - processor/spc700: various cleanups to instruction function naming
  - processor/z80: prefix state (HL→IX,IY override) can now be
    serialized
  - icarus: fix install rule for certain platforms (it wasn't buggy on
    FreeBSD, but was on Linux?)

¹: the clock speed of the PSG is oscillator/15. But I was setting the
sampling rate to oscillator/15/16, which was around 223KHz. I am not
sure whether the PSG should be outputting at 3MHz or 223KHz. Amazingly
... I don't really hear a difference either way `o_O` I didn't actually
mean to make this change; I just noticed it after comparing the diff
between r01 and r02. If this turns out to be wrong, set

    stream = Emulator::audio.createStream(1, frequency() / 16.0);

in md/psg.cpp to revert this change.
2017-06-27 11:18:28 +10:00
Tim Allen ecc7e899e0 Update to v103r01 release.
byuu says:

Changelog:

  - nall/dsp: improve one pole coefficient calculations [Fatbag]
  - higan/audio: reworked filters to support selection of either one
    pole (first-order) or biquad (second-order) filters
      - note: the design is not stable yet; so forks should not put too
        much effort into synchronizing with this change yet
  - fc: added first-order filters as per NESdev wiki (90hz lowpass +
    440hz lowpass + 14khz highpass)
  - fc: created separate NTSC-J and NTSC-U regions
      - NESdev wiki says the Japanese Famicom uses a separate audio
        filtering strategy, but details are fuzzy
      - there's also cartridge audio output being disabled on NES units;
        and differences with controllers
      - this stuff will be supported in the future, just adding the
        support for it now
  - gba: corrected serious bugs in PSG wave channel emulation [Cydrak]
      - note that if there are still bugs here, it's my fault
  - md/psg,ym2612: added first-order low-pass 2840hz filter to match
    VA3-VA6 Mega Drives
  - md/psg: lowered volume relative to the YM2612
      - using 0x1400; multiple people agreed it was the closest to the
        hardware recordings against a VA6
  - ms,md/psg: don't serialize the volume levels array
  - md/vdp: Hblank bit acts the same during Vblank as outside of it (it
    isn't always set during Vblank)
  - md/vdp: return isPAL in bit 0 of control port reads
  - tomoko: change command-line option separator from : to |
      - [Editor's note: This change was present in the public v103,
        but it's in this changelog because it was made after the v103 WIP]
  - higan/all: change the 20hz high-pass filters from second-order
    three-pass to first-order one-pass
      - these filters are meant to remove DC bias, but I honestly can't
        hear a difference with or without them
      - so there's really no sense wasting CPU power with an extremely
        powerful filter here

Things I did not do:

  - change icarus install rule
  - work on 8-bit Mega Drive SRAM
  - work on Famicom or Mega Drive region detection heuristics in icarus

My long-term dream plan is to devise a special user-configurable
filtering system where you can set relative volumes and create your own
list of filters (any number of them in any order at any frequency), that
way people can make the systems sound however they want.

Right now, the sanest place to put this information is inside the
$system.sys/manifest.bml files. But that's not very user friendly, and
upgrading to new versions will lose these changes if you don't copy them
over manually. Of course, cluttering the GUI with a fancy filter editor
is probably supreme overkill for 99% of users, so maybe that's fine.
2017-06-26 11:41:58 +10:00
Tim Allen b7006822bf Update to v103 WIP release.
byuu says (in the WIP forum):

Changelog:

  - higan: cheat codes accept = and ? separators now
      - the new preferred code format is: address=value or
        address=if-match?value
      - the old code format of address/value and address/if-match/value
        will continue to work
  - higan: cheats.bml is no longer included with the base distribution
      - mightymo stopped updating it in 2015, and it's not source code;
        it can still be pulled in from older releases
  - fc: improved PAL mode timing; use PAL APU timing tables; fix PAL
    noise period table [hex\_usr]
  - md: support aborting a Z80 bus wait in order to capture save states
    without freezing
      - note that this will violate accuracy; but in practice a slight
        desync is better than an emulator deadlock
  - sfc: revert DSP ENDX randomization for now (want to research it more
    before deploying in an official release)
  - sfc: fix Super Famicom.sys/manifest.bml APU RAM size [hex\_usr]
  - tomoko: cleaned up make install rules
  - hiro/cocoa: use ABGR for pixel data [Sintendo]

Note: I forgot to change the command-line and drag-and-drop separator
from : to | in this WIP. However, it is corrected in the v103 official
binary and source published on download.byuu.org. Sorry about that, I
know it makes the Git repository history more difficult. I'm not
concerned whether the : → | change is part of v103 or v103r01 in the
repository, and will leave this to your discretion, Screwtape.

I also still need to set the VDP bit to indicate PAL mode in the Mega
Drive core. This is what happens when I have 47 things I have to do,
given how lousy my memory is. I miss things.
2017-06-22 16:10:13 +10:00
Tim Allen 8476f35153 Update to v102r28 release.
byuu says:

Changelog:

  - higan: `Emulator::<Platform::load>()` now returns a struct containing
    both a path ID and a string option
  - higan: `Emulator::<Platform::load>()` now takes an optional final
    argument of string options
  - fc: added PAL emulation (finally, only took six years)
  - md: added PAL emulation
  - md: fixed address parameter to `VDP::Sprite::write()`; fixes missing
    sprites in Super Street Fighter II
  - md: emulated HIRQ counter; fixes many games
      - Super Street Fighter II - status bar
      - Altered Beast - status bar
      - Sonic the Hedgehog - Labyrinth Zone - water effect
      - etc.
  - ms: added PAL emulation
  - sfc: added the ability to override the default region auto-detection
  - sfc: removed "system.region" override setting from `Super Famicom.sys`
  - tomoko: added options list to game folder load dialog window
  - tomoko: added the ability to specify game folder load options on the
    command-line

So, basically ... Sega forced a change with the way region detection
works. You end up with games that can run on multiple regions, and the
content changes accordingly. Bare Knuckle in NTSC-J mode will become
Streets of Rage in NTSC-U mode. Some games can even run in both NTSC and
PAL mode.

In my view, there should be a separate ROM for each region a game was
released in, even if the ROM content were identical. But unfortunately
that's not how things were done by anyone else.

So to support this, the higan load dialog now has a drop-down at the
bottom-right, where you can choose the region to load games from. On the
SNES, it defaults to "Auto", which will pull the region setting from the
manifest, or fall back on NTSC. On the Mega Drive ... unfortunately, I
can't auto-detect the region from the ROM header. $1f0 is supposed to
contain a string like "JUE", but instead you get games like Maui Mallard
that put an "A" there, and other such nonsense. Sega was far more lax
than Nintendo with the ROM header validity. So for now at least, you
have to manually select your region every time you play a Mega Drive
game, thus you have "NTSC-J", "NTSC-U", and "PAL". The same goes for the
Master System for the same reason, but there's only "NTSC" and "PAL"
here. I'm not sure if games have a way to detect domestic vs
international consoles.

And for now ... the Famicom is the same as well, with no auto-detection.
I'd sincerely hope iNES has a header bit for the region, but I didn't
bother with updating icarus to support that yet.

The way to pass these parameters on the command-line is to prefix the
game path with "option:", so for example:

    higan "PAL:/path/to/Sonic the Hedgehog (USA, Europe).md"

If you don't provide a prefix, it uses the default (NTSC-J, NTSC, or
Auto.) Obviously, it's not possible to pass parameters with
drag-and-drop, so you will always get the default option in said case.
2017-06-20 22:34:50 +10:00
Tim Allen 50411a17d1 Update to v102r26 release.
byuu says:

Changelog:

  - md/ym2612: initialize DAC sample to center volume [Cydrak]
  - processor/arm: add accumulate mode extra cycle to mlal [Jonas
    Quinn]
  - processor/huc6280: split off algorithms, improve naming of functions
  - processor/mos6502: split off algorithms
  - processor/spc700: major revamp of entire core (~50% completed)
  - processor/wdc65816: fixed several bugs introduced by rewrite

For the SPC700, this turns out to be very old code as well, with global
object state variables, those annoying `{Boolean,Natural}BitField` types,
`under_case` naming conventions, heavily abbreviated function names, etc.
I'm working to get the code to be in the same design as the MOS6502,
HuC6280, WDC65816 cores, since they're all extremely similar in terms of
architectural design (the SPC700 is more of an off-label
reimplementation of a 6502 core, but still.)

The main thing left is that about 90% of the actual instructions still
need to be adapted to not use the internal state (`aa`, `rd`, `dp`,
`sp`, `bit` variables.) I wanted to finish this today, but ran out of
time before work.

I wouldn't suggest too much testing just yet. We should wait until the
SPC700 core is finished for that. However, if some does want to and
spots regressions, please let me know.
2017-06-16 10:06:17 +10:00
Tim Allen 6e8406291c Update to v102r24 release.
byuu says

Changelog:

  - FC: fixed three MOS6502 regressions [hex\_usr]
  - GBA: return fetched instruction instead of 0 for unmapped MMIO
    (passes all of endrift's I/O tests)
  - MD: fix VDP control port read Vblank bit to test screen height
    instead of hard-code 240 (fixes Phantasy Star IV)
  - MD: swap USP,SSP when executing an exception (allows Super Street
    Fighter II to run; but no sprites visible yet)
  - MD: grant 68K access to Z80 bus on reset (fixes vdpdoc demo ROM from
    freezing immediately)
  - SFC: reads from $00-3f,80-bf:4000-43ff no longer update MDR
    [p4plus2]
  - SFC: massive, eight-hour cleanup of WDC65816 CPU core ... still not
    complete

The big change this time around is the SFC CPU core. I've renamed
everything from R65816 to WDC65816, and then went through and tried to
clean up the code as much as possible. This core is so much larger than
the 6502 core that I chose cleaning up the code to rewriting it.

First off, I really don't care for the BitRange style functionality. It
was an interesting experiment, but its fatal flaw are that the types are
just bizarre, which makes them hard to pass around generically to other
functions as arguments. So I went back to the list of bools for flags,
and union/struct blocks for the registers.

Next, I renamed all of the functions to be more descriptive: eg
`op_read_idpx_w` becomes `instructionIndexedIndirectRead16`. `op_adc_b`
becomes `algorithmADC8`. And so forth.

I eliminated about ten instructions because they were functionally
identical sans the index, so I just added a uint index=0 parameter to
said functions. I added a few new ones (adjust→INC,DEC;
pflag→REP,SEP) where it seemed appropriate.

I cleaned up the disaster of the instruction switch table into something
a whole lot more elegant without all the weird argument decoding
nonsense (still need M vs X variants to avoid having to have 4-5
separate switch tables, but all the F/I flags are gone now); and made
some things saner, like the flag clear/set and branch conditions, now
that I have normal types for flags and registers once again.

I renamed all of the memory access functions to be more descriptive to
what they're doing: eg writeSP→push, readPC→fetch,
writeDP→writeDirect, etc. Eliminated some of the special read/write
modes that were only used in one single instruction.

I started to clean up some of the actual instructions themselves, but
haven't really accomplished much here. The big thing I want to do is get
rid of the global state (aa, rd, iaddr, etc) and instead use local
variables like I am doing with my other 65xx CPU cores now. But this
will take some time ... the algorithm functions depend on rd to be set
to work on them, rather than taking arguments. So I'll need to rework
that.

And then lastly, the disassembler is still a mess. I want to finish the
CPU cleanups, and then post a new WIP, and then rewrite the disassembler
after that. The reason being ... I want a WIP that can generate
identical trace logs to older versions, in case the CPU cleanup causes
any regressions. That way I can more easily spot the errors.

Oh ... and a bit of good news. v102 was running at ~140fps on the SNES
core. With the new support to suspend/resume WAI/STP, plus the internal
CPU registers not updating the MDR, the framerate dropped to ~132fps.
But with the CPU cleanups, performance went back to ~140fps. So, hooray.
Of course, without those two other improvements, we'd have ended up at
possibly ~146-148fps, but oh well.
2017-06-13 11:42:31 +10:00
Tim Allen 8af3e4a6e2 Update to v102r22 release.
byuu says:

Changelog:

  - higan: Emulator::Interface::videoSize() renamed to videoResolution()
  - higan: Emulator::Interface::rtcsync() renamed to rtcSynchronize()
  - higan: added video display rotation support to Video
  - GBA: substantially improved audio mixing
      - fixed bug with FIFO 50%/100% volume setting
      - now properly using SOUNDBIAS amplitude to control output
        frequencies
      - reduced quantization noise
      - corrected relative volumes between PSG and FIFO channels
      - both PSG and FIFO values cached based on amplitude; resulting in
        cleaner PCM samples
      - treating PSG volume=3 as 200% volume instead of 0% volume now
        (unverified: to match mGBA)
  - GBA: properly initialize ALL CPU state; including the vital
    prefetch.wait=1 (fixes Classic NES series games)
  - GBA: added video rotation with automatic key translation support
  - PCE: reduced output resolution scalar from 285x242 to 285x240
      - the extra two scanlines won't be visible on most TVs; and they
        make all other cores look worse
      - this is because all other cores output at 240p or less; so they
        were all receiving black bars in windowed mode
  - tomoko: added "Rotate Display" hotkey setting
  - tomoko: changed hotkey multi-key logic to OR instead of AND
      - left support for flipping it back inside the core; for those so
        inclined; by uncommenting one line in input.hpp
  - tomoko: when choosing Settings→Configuration, it will
    automatically select the currently loaded system
      - for instance, if you're playing a Game Gear game, it'll take you
        to the Game Gear input settings
      - if no games are loaded, it will take you to the hotkeys panel
        instead
  - WS(C): merged "Hardware-Vertical", "Hardware-Horizontal" controls
    into combined "Hardware"
  - WS(C): converted rotation support from being inside the core to
    using Emulator::Video
      - this lets WS(C) video content scale larger now that it's not
        bounded by a 224x224 square box
  - WS(C): added automatic key rotation support
  - WS(C): removed emulator "Rotate" key (use the general hotkey
    instead; I recommend F8 for this)
  - nall: added serializer support for nall::Boolean (boolean) types
      - although I will probably prefer the usage of uint1 in most cases
2017-06-09 00:08:02 +10:00
Tim Allen 82c58527c3 Update to v102r17 release.
byuu says:

Changelog:

  - GBA: process audio at 2MHz instead of 32KHz¹
  - MD: do not allow the 68K to stop the Z80, unless it has been granted
    bus access first
  - MD: do not reset bus requested/granted signals when the 68K resets
    the Z80
      - the above two fix The Lost Vikings
  - MD: clean up the bus address decoding to be more readable
  - MD: add support for a13000-a130ff (#TIME) region; pass to cartridge
    I/O²
  - MD: emulate SRAM mapping used by >16mbit games; bank mapping used
    by >32mbit games³
  - MD: add 'reset pending' flag so that loading save states won't
    reload 68K PC, SP registers
      - this fixes save state support ... mostly⁴
  - MD: if DMA is not enabled, do not allow CD5 to be set [Cydrak]
      - this fixes in-game graphics for Ristar. Title screen still
        corrupted on first run
  - MD: detect and break sprite lists that form an infinite loop
    [Cydrak]
      - this fixes the emulator from dead-locking on certain games
  - MD: add DC offset to sign DAC PCM samples [Cydrak]
      - this improves audio in Sonic 3
  - MD: 68K TAS has a hardware bug that prevents writing the result back
    to RAM
      - this fixes Gargoyles
  - MD: 68K TRAP should not change CPU interrupt level
      - this fixes Shining Force II, Shining in the Darkness, etc
  - icarus: better SRAM heuristics for Mega Drive games

Todo:

  - need to serialize the new cartridge ramEnable, ramWritable, bank
    variables

¹: so technically, the GBA has its FIFO queue (raw PCM), plus a GB
chipset. The GB audio runs at 2MHz. However, I was being lazy and
running the sequencer 64 times in a row, thus decimating the audio to
32KHz. But simply discarding 63 out of every 64 samples resorts in
muddier sound with more static in it.

However ... increasing the audio thread processing intensity 64-fold,
and requiring heavy-duty three-chain lowpass and highpass filters is not
cheap. For this bump in sound quality, we're eating a loss of about 30%
of previous performance.

Also note that the GB audio emulation in the GBA core still lacks many
of the improvements made to the GB core. I was hoping to complete the GB
enhancements, but it seems like I'm never going to pass blargg's
psychotic edge case tests. So, first I want to clean up the GB audio to
my current coding standards, and then I'll port that over to the GBA,
which should further increase sound quality. At that point, it sound
exceed mGBA's audio quality (due to the ridiculously high sampling rate
and strong-attenuation audio filtering.)

²: word writes are probably not handled correctly ... but games are
only supposed to do byte writes here.

³: the SRAM mapping is used by games like "Story of Thor" and
"Phantasy Star IV." Unfortunately, the former wasn't released in the US
and is region protected. So you'll need to change the NTSU to NTSCJ in
md/system/system.cpp in order to boot it. But it does work nicely now.
The write protection bit is cleared in the game, and then it fails to
write to SRAM (soooooooo many games with SRAM write protection do this),
so for now I've had to disable checking that bit. Phantasy Star IV has a
US release, but sadly the game doesn't boot yet. Hitting some other bug.

The bank mapping is pretty much just for the 40mbit Super Street Fighter
game. It shows the Sega and Capcom logos now, but is hitting yet another
bug and deadlocking.

For now, I emulate the SRAM/bank mapping registers on all cartridges,
and set sane defaults. So long as games don't write to $a130XX, they
should all continue to work. But obviously, we need to get to a point
where higan/icarus can selectively enable these registers on a per-game
basis.

⁴: so, the Mega Drive has various ways to lock a chip until another
chip releases it. The VDP can lock the 68K, the 68K can lock the Z80,
etc. If this happens when you save a state, it'll dead-lock the
emulator. So that's obviously a problem that needs to be fixed. The fix
will be nasty ... basically, bypassing the dead-lock, creating a
miniature, one-instruction-long race condition. Extremely unlikely to
cause any issues in practice (it's only a little worse than the SNES
CPU/SMP desync), but ... there's nothing I can do about it. So you'll
have to take it or leave it. But yeah, for now, save states may lock up
the emulator. I need to add code to break the loops when in the process
of creating a save state still.
2017-03-10 21:23:29 +11:00
Tim Allen 04072b278b Update to v102r16 release.
byuu says:

Changelog:

  - Emulator::Stream now allows adding low-pass and high-pass filters
    dynamically
      - also accepts a pass# count; each pass is a second-order biquad
        butterworth IIR filter
  - Emulator::Stream no longer automatically filters out >20KHz
    frequencies for all streams
  - FC: added 20Hz high-pass filter; 20KHz low-pass filter
  - GB: removed simple 'magic constant' high-pass filter of unknown
    cutoff frequency (missed this one in the last WIP)
  - GB,SGB,GBC: added 20Hz high-pass filter; 20KHz low-pass filter
  - MS,GG,MD/PSG: added 20Hz high-pass filter; 20KHz low-pass filter
  - MD: added save state support (but it's completely broken for now;
    sorry)
  - MD/YM2612: fixed Voice#3 per-operator pitch support (fixes sound
    effects in Streets of Rage, etc)
  - PCE: added 20Hz high-pass filter; 20KHz low-pass filter
  - WS,WSC: added 20Hz high-pass filter; 20KHz low-pass filter

So, the point of the low-pass filters is to remove frequencies above
human hearing. If we don't do this, then resampling will introduce
aliasing that results in sounds that are audible to the human ear. Which
basically an annoying buzzing sound. You'll definitely hear the
improvement from these in games like Mega Man 2 on the NES. Of course,
these already existed before, so this WIP won't sound better than
previous WIPs.

The high-pass filters are a little more complicated. Their main role is
to remove DC bias and help to center the audio stream. I don't
understand how they do this at all, but ... that's what everyone who
knows what they're talking about says, thus ... so be it.

I have set all of the high-pass filters to 20Hz, which is below the
limit of human hearing. Now this is where it gets really interesting ...
technically, some of these systems actually cut off a lot of range. For
instance, the GBA should technically use an 800Hz high-pass filter when
output is done through the system's speakers. But of course, if you plug
in headphones, you can hear the lower frequencies.

Now 800Hz ... you definitely can hear. At that level, nearly all of the
bass is stripped out and the audio is very tinny. Just like the real
system. But for now, I don't want to emulate the audio being crushed
that badly.

I'm sticking with 20Hz everywhere since it won't negatively affect audio
quality. In fact, you should not be able to hear any difference between
this WIP and the previous WIP. But theoretically, DC bias should mostly
be removed as a result of these new filters. It may be that we need to
raise the values on some cores in the future, but I don't want to do
that until we know for certain that we have to.

What I can say is that compared to even older WIPs than r15 ... the
removal of the simple one-pole low-pass and high-pass filters with the
newer three-pass, second-order filters should result in much better
attenuation (less distortion of audible frequencies.) Probably not
enough to be noticeable in a blind test, though.
2017-03-09 07:20:40 +11:00
Tim Allen 7e7003fd29 Update to v102r15 release.
byuu says:

Changelog:

  - nall: added DSP::IIR::OnePole (which is a first-order IIR filter)
  - FC/APU: removed strong highpass, weak hipass filters (and the
    dummied out lowpass filter)
  - MS,GG,MD/PSG: removed lowpass filter
  - MS,GG,MD/PSG: audio was not being centered properly; removed
    centering for now
  - MD/YM2612: fixed clipping of accumulator from 18 signed bits to 14
    signed bits (-0x2000 to +0x1fff) [Cydrak]
  - MD/YM2612: removed lowpass filter
  - PCE/PSG: audio was not being centered properly; removed centering
    for now

First thing is that I've removed all of the ad-hoc audio filtering.
Emulator::Stream intrinsically provides a three-pass, second-order
biquad IIR butterworth lowpass filter that clips frequencies above 20KHz
with very good attenuation (as good as IIR gets, anyway.)

It doesn't really make sense to have the various cores running
additional lowpass filters. If we want to filter frequencies below
20KHz, then I can adapt Emulator::Audio::createStream() to take a cutoff
frequency value, and we can do it all at once, with much better quality.

Right now, I don't know what frequencies are best to cut off the various
other audio cores, so they're just gone for now.

As for the highpass filters for the Famicom core, well ... you don't get
aliasing from resampling low frequencies. And generally speaking, too
low a frequency will be inaudible anyway. All these were doing was
killing possible bass (if they were too strong.) We can add them again,
but only if someone can convert Ryphecha's ad-hoc magic integers into a
frequency cutoff. In which case, I'll use my biquad IIR filter to do it
even better. On this note, it may prove useful to do this for the MD PSG
as well, to try and head off unnecessary clamping when mixing with the
YM2612.

Finally, there was the audio centering issue that affected the
MS,GG,MD,PCE,SG cores. It was flooring the "silent" audio level, which
was resulting in extremely heavy distortion if you tried listening to
higan and, say, audacious at the same time. Without the botched
centering, this distortion is completely gone now.

However, without any centering, we've halved the potential volume range.
This means the audio slider in higan's audio settings panel will start
clamping twice as quickly. So ultimately, we need to figure out how to
fix the centering. This isn't as simple as just subtracting less. We
will probably have to center every individual audio channel before
summing them to do this properly.

Results:

On the Mega Drive, Altered Beast sounds quite a bit better, a lot less
distortion now. But it's still not perfect, especially sound effects.
Further, Bare Knuckle / Streets of Rage still has really bad sound
effects. It looks like I broke something in Cydrak's code when trying to
adapt it to my style =(
2017-03-07 07:23:22 +11:00
Tim Allen 89d47914b9 Update to v102r14 release.
byuu says:

Changelog:

  - (MS,GG,MD)/PSG: flip output bit from noise channel [TmEE]
  - MD/YM2612: rewrite YM2612::Channel functions to
    YM2612::Channel::Operator functions¹
  - MD/YM2612: pitch/octave I/O registers should set reload, not value
    (fixes sound in most games)
  - MD/YM2612: don't try to sign-extend raw PCM values (fixes Shining
    Force opening music)
  - MD/YM2612: various algorithm simplifications; conversions from
    `*`, `/`, `%` to `<<`, `>>`; etc.

Overall ... Sonic the Hedgehog sounds really, really great. Almost
perfect, but there's a bit of clamping going on in the special zones.
Langrisser II sounds really great. Shining Force sounds pretty much
perfect. Bare Knucles (Streets of Rage) does pretty badly ... punches
sound more like dinging a salad fork on a wine glass, heh. Altered Beast
is extremely broken ... no music at the title screen, very distorted
in-game music. I suspect a bug outside of the YM2612 is affecting this
game.

So, the YM2612 emulation isn't perfect, but it's a really good start to
the most complex sound chip in all of higan. Hopefully the VRC7 and
YM2413 will prove to be less ferocious ... not that I'm in any rush to
work on either. The former is going to need the NES mapper rewrite to be
done first, and the latter is cool but not very necessary since all
those games have fallbacks to the inferior PSG audio.

But really ... I can't thank Cydrak enough for doing this for me. It
would have probably taken me months to parse through all of the
documentation on this chip (most of which is in a 55-page thread on
spritesmind that is filled with wrong/outdated information at the start,
and corrections as you go deeper.) Not to mention, learning about what
the hell detuning, low-frequency oscillation, tremolo, vibrato, etc were
all about. Or how those algorithms to compute the final output work. Or
the dozens of special cases littered in there to make everything sound
good. Fierce, nasty chip that.

Now the last real problem is save states ... the Mega Drive is going to
be the trickiest of all to implement with libco. There are lots of areas
where one chip will deadlock another chip while it completes some
operation. We don't have a choice but to force those stalls to abort
anyway, in order to let libco reach the start of its entry point once
again. I don't know what kind of impact that'll have on states ... I
suspect they'll work almost as reliably as the SNES does, but I can't
know that until I implement it. It's going to be pretty nasty, though.

¹: this basically removes a lot of unnecessary op. prefixes and the
need to capture `auto& op = operators[index]` at the start of every
function.

I wanted to have subfunctions like
`YM2612::Channel::Operator::Envelope::run()`, etc but unfortunately,
pretty much all of the envelope, phase, pitch, level functions need to
access each other's state.
2017-03-03 21:45:07 +11:00
Tim Allen 0bf2c9d4e1 Update to v102r13 release.
byuu says:

Changelog:

  - removed Emulator::Interface::videoFrequency(), audioFrequency()¹
  - (MS,GG,MD)/PSG: removed inversion on noise channel LFSR update
    [mic_]
  - MD/PSG: lowered volume to match YM2612 volume
  - MD/YM2612: added Cydrak's emulation of FM channels and LFO²

¹: These were no longer used by the UI. The video frequency is
adaptive on many systems. And the audio frequency is meaningless due to
Emulator::Audio always outputting a consistent frequency specified by
the UI. Plus, take the Genesis where there's two sound chips running at
different frequencies. So, these had to go.

²: Due to some lurking bugs, the audio is completely broken
unfortunately. Will need to be debugged :(

First pass looking for any typos didn't yield any obvious results.
2017-03-02 07:40:55 +11:00
Tim Allen 4c3f9b93e7 Update to v102r12 release.
byuu says:

Changelog:

  - MD/PSG: fixed 68K bus Z80 status read address location
  - MS, GG, MD/PSG: channels post-decrement their counters, not
    pre-decrement [Cydrak]¹
  - MD/VDP: cache screen width registers once per scanline; screen
    height registers once per frame
  - MD/VDP: support 256-width display mode (used in Shining Force, etc)
  - MD/YM2612: implemented timers²
  - MD/YM2612: implemented 8-bit PCM DAC²
  - 68000: TRAP instruction should index the vector location by 32 (eg
    by 128 bytes), fixes Shining Force
  - nall: updated hex(), octal(), binary() functions to take uintmax
    instead of template<typename T> parameter³

¹: this one makes an incredible difference. Sie noticed that lots of
games set a period of 0, which would end up being a really long period
with pre-decrement. By fixing this, noise shows up in many more games,
and sounds way better in games even where it did before. You can hear
extra sound on Lunar - Sanposuru Gakuen's title screen, the noise in
Sonic The Hedgehog (Mega Drive) sounds better, etc.

²: this also really helps sound. The timers allow PSG music to play
back at the correct speed instead of playing back way too quickly. And
the PCM DAC lets you hear a lot of drum effects, as well as the
"Sega!!" sound at the start of Sonic the Hedgehog, and the infamous,
"Rise from your grave!" line from Altered Beast.

Still, most music on the Mega Drive comes from the FM channels, so
there's still not a whole lot to listen to.

I didn't implement Cydrak's $02c test register just yet. Sie wasn't 100%
certain on how the extended DAC bit worked, so I'd like to play it a
little conservative and get sound working, then I'll go back and add a
toggle or something to enable undocumented registers, that way we can
use that to detect any potential problems they might be causing.

³: unfortunately we lose support for using hex() on nall/arithmetic
types. If I have a const Pair& version of the function, then the
compiler gets confused on whether Natural<32> should use uintmax or
const Pair&, because compilers are stupid, and you can't have explicit
arguments in overloaded functions. So even though either function would
work, it just decides to error out instead >_>

This is actually really annoying, because I want hex() to be useful for
printing out nall/crypto keys and hashes directly.

But ... this change had to be made. Negative signed integers would crash
programs, and that was taking out my 68000 disassembler.
2017-02-27 19:45:51 +11:00
Tim Allen 1cab2dfeb8 Update to v102r11 release.
byuu says:

Changelog:

  - MD: connected 32KB cartridge RAM up to every Genesis game under 2MB
    loaded¹
  - MS, GG, MD: improved PSG noise channel emulation, hopefully²
  - MS, GG, MD: lowered PSG volume so that the lowpass doesn't clamp
    samples³
  - MD: added read/write handlers for VRAM, VSRAM, CRAM
  - MD: block VRAM copy when CD4 is clear⁴
  - MD: rewrote VRAM fill, VRAM copy to be byte-based⁵
  - MD: VRAM fill byte set should fall through to regular data port
    write handler⁶

¹: the header parsing for backup RAM is really weird. It's spaces
when not used, and seems to be 0x02000001-0x02003fff for the Shining
games. I don't understand why it starts at 0x02000001 instead of
0x02000000. So I'm just forcing every game to have 32KB of RAM for now.
There's also special handling for ROMs > 2MB that also have RAM
(Phantasy Star IV, etc) where there's a toggle to switch between ROM and
RAM. For now, that's not emulated.

I was hoping the Shining games would run after this, but they're still
dead-locking on me :(

²: Cydrak pointed out some flaws in my attempt to implement what he
had. I was having trouble understanding what he meant, so I went back
and read the docs on the sound chip and tried implementing the counter
the way the docs describe. Hopefully I have this right, but I don't know
of any good test ROMs to make sure my noise emulation is correct. The
docs say the shifted-out value goes to the output instead of the low bit
of the LFSR, so I made that change as well.

I think I hear the noise I'm supposed to in Sonic Marble Zone now, but
it seems like it's not correct in Green Hill Zone, adding a bit of an
annoying buzz to the background music. Maybe it sounds better with the
YM2612, but more likely, I still screwed something up :/

³: it's set to 50% range for both cores right now. For the MD, it
will need to be 25% once YM2612 emulation is in.

⁴: technically, this deadlocks the VDP until a hard reset. I could
emulate this, but for now I just don't do the VRAM copy in this case.

⁵: VSRAM fill and CRAM fill not supported in this new mode. They're
technically undocumented, and I don't have good notes on how they work.
I've been seeing conflicting notes on whether the VRAM fill buffer is
8-bits or 16-bits (I chose 8-bits), and on whether you write the low
byte and then high byte of each words, or the high byte and then low
byte (I chose the latter.)

The VRAM copy improvements fix the opening text in Langrisser II, so
that's great.

⁶: Langrisser II sets the transfer length to one less than needed to
fill the background letter tile on the scenario overview screen. After
moving to byte-sized transfers, a black pixel was getting stuck there.
So effectively, VRAM fill length becomes DMA length + 1, and the first
byte uses the data port so it writes a word value instead of just a byte
value. Hopefully this is all correct, although it probably gets way more
complicated with the VDP FIFO.
2017-02-25 22:11:46 +11:00
Tim Allen 68f04c3bb8 Update to v102r10 release.
byuu says:

Changelog:

  - removed Emulator::Interface::Capabilities¹
  - MS: improved the PSG emulation a bit
  - MS: added cheat code support
  - MS: added save state support²
  - MD: emulated the PSG³

¹: there's really no point to it anymore. I intend to add cheat codes
to the GBA core, as well as both cheat codes and save states to the Mega
Drive core. I no longer intend to emulate any new systems, so these
values will always be true. Further, the GUI doesn't respond to these
values to disable those features anymore ever since the hiro rewrite, so
they're double useless.

²: right now, the Z80 core is using a pointer for HL-\>(IX,IY)
overrides. But I can't reliably serialize pointers, so I need to convert
the Z80 core to use an integer here. The save states still appear to
work fine, but there's the potential for an instruction to execute
incorrectly if you're incredibly unlucky, so this needs to be fixed as
soon as possible. Further, I still need a way to serialize
array<T, Size> objects, and I should also add nall::Boolean
serialization support.

³: I don't have a system in place to share identical sound chips. But
this chip is so incredibly simple that it's not really much trouble to
duplicate it. Further, I can strip out the stereo sound support code
from the Game Gear portion, so it's even tinier.

Note that the Mega Drive only just barely uses the PSG. Not at all in
Altered Beast, and only for a tiny part of the BGM music on Sonic 1,
plus his jump sound effect.
2017-02-23 08:25:01 +11:00
Tim Allen 8071da4c6a Update to v102r09 release.
byuu says:

Changelog:

  - MD: restructured DMA to a subclass of VDP
  - MD: implemented VRAM copy mode (fixes Langrisser II ... mostly)
  - MS: implemened PSG support [Cydrak]
  - GG: implemented PSG stereo sound support
  - MS: use the new struct Model {} design that other cores use

The MS/GG PSG should be feature complete, but I don't have good tests
for Game Gear stereo mode, nor for the noise channel. There's also a
really weird behavior with when to reload the channel counters on volume
register writes. I can confirm what Cydrak observed in that following
the docs and reloading always creates serious audio distortion problems.
So, more research is needed there.

To get the correct sound out of the PSG, I have to run it at 3.58MHz /
16, which seems really weird to me. The docs make it sound like it's
supposed to run at the full 3.58MHz. If we can really run it at
223.7KHz, then that's help reduce the overhead of PSG emulation, which
will definitely come in handy for Mega Drive, and possibly later Mega
CD, emulation.

I have not implemented the PSG into the Mega Drive just yet. Nor have I
implemented save states or cheat code support into the MS/GG cores yet.
The latter is next on my list.
2017-02-21 22:07:33 +11:00
Tim Allen d76c0c7e82 Update to v102r08 release.
byuu says:

Changelog:

  - PCE: restructured VCE, VDCs to run one scanline at a time
  - PCE: bound VDCs to 1365x262 timing (in order to decouple the VDCs
    from the VCE)
  - PCE: the two changes above allow save states to function; also
    grants a minor speed boost
  - PCE: added cheat code support (uses 21-bit bus addressing; compare
    byte will be useful here)
  - 68K: fixed `mov *,ccr` to read two bytes instead of one [Cydrak]
  - Z80: emulated /BUSREQ, /BUSACK; allows 68K to suspend the Z80
    [Cydrak]
  - MD: emulated the Z80 executing instructions [Cydrak]
  - MD: emulated Z80 interrupts (triggered during each Vblank period)
    [Cydrak]
  - MD: emulated Z80 memory map [Cydrak]
  - MD: added stubs for PSG, YM2612 accesses [Cydrak]
  - MD: improved bus emulation [Cydrak]

The PCE core is pretty much ready to go. The only major feature missing
is FM modulation.

The Mega Drive improvements let us start to see the splash screens for
Langrisser II, Shining Force, Shining in the Darkness. I was hoping I
could get them in-game, but no such luck. My Z80 implementation is
probably flawed in some way ... now that I think about it, I believe I
missed the BusAPU::reset() check for having been granted access to the
Z80 first. But I doubt that's the problem.

Next step is to implement Cydrak's PSG core into the Master System
emulator. Once that's in, I'm going to add save states and cheat code
support to the Master System core.

Next, I'll add the PSG core into the Mega Drive. Then I'll add the
'easy' PCM part of the YM2612. Then the rest of the beastly YM2612 core.
Then finally, cap things off with save state and cheat code support.

Should be nearing a new release at that point.
2017-02-20 19:13:10 +11:00
Tim Allen fa6cbac251 Update to v102r06 release.
byuu says:

Changelog:

  - added higan/emulator/platform.hpp (moved out Emulator::Platform from
    emulator/interface.hpp)
  - moved gmake build paramter to nall/GNUmakefile; both higan and
    icarus use it now
  - added build=profile mode
  - MD: added the region select I/O register
  - MD: started to add region selection support internally (still no
    external select or PAL support)
  - PCE: added cycle stealing when reading/writing to the VDC or VCE;
    and when using ST# instructions
  - PCE: cleaned up PSG to match the behavior of Mednafen (doesn't
    improve sound at all ;_;)
      - note: need to remove loadWaveSample, loadWavePeriod
  - HuC6280: ADC/SBC decimal mode consumes an extra cycle; does not set
    V flag
  - HuC6280: block transfer instructions were taking one cycle too many
  - icarus: added code to strip out PC Engine ROM headers
  - hiro: added options support to BrowserDialog

The last one sure ended in failure. The plan was to put a region
dropdown directly onto hiro::BrowserDialog, and I had all the code for
it working. But I forgot one important detail: the system loads
cartridges AFTER powering on, so even though I could technically change
the system region post-boot, I'd rather not do so.

So that means we have to know what region we want before we even select
a game. Shit.
2017-02-11 10:56:42 +11:00
Tim Allen ee7662a8be Update to v102r04 release.
byuu says:

Changelog:
  - Super Game Boy support is functional once again
  - new GameBoy::SuperGameBoyInterface class
  - system.(dmg,cgb,sgb) is now Model::(Super)GameBoy(Color) ala the PC
    Engine
  - merged WonderSwanInterface, WonderSwanColorInterface shared
    functions to WonderSwan::Interface
  - merged GameBoyInterface, GameBoyColorInterface shared functions to
    GameBoy::Interface
  - Interface::unload() now calls Interface::save() for Master System,
    Game Gear, Mega Drive, PC Engine, SuperGrafx
  - PCE: emulated PCE-CD backup RAM; stored per-game as save.ram (2KiB
    file)
      - this means you can now save your progress in games like Neutopia
      - the PCE-CD I/O registers like BRAM write protect are not
        emulated yet
  - PCE: IRQ sources now hold the IRQ line state, instead of the CPU
    holding it
      - this fixes most SuperGrafx games, which were fighting over the
        VDC IRQ line previously
  - PCE: CPU I/O $14xx should return the pending IRQ bits even if IRQs
    are disabled
  - PCE: VCE and the VDCs now synchronize to each other; fixes pixel
    widths in all games
  - PCE: greatly increased the accuracy of the VPC priority selection
    code (windows may be buggy still)
  - HuC6280: PLA, PLX, PLY should set Z, N flags; fixes many game bugs
    [Jonas Quinn]

The big thing I wanted to do was enslave the VDC(s) to the VCE. But
unfortunately, I forgot about the asynchronous DMA channels that each
VDC supports, so this isn't going to be possible I'm afraid.

In the most demanding case, Daimakaimura in-game, we're looking at 85fps
on my Xeon E3 1276v3. So ... not great, and we don't even have sound
connected yet.

We are going to have to profile and optimize this code once sound
emulation and save states are in.

Basically, think of it like this: the VCE, VDC0, and VDC1 all have the
same overhead, scheduling wise (which is the bulk of the performance
loss) as the dot-renderer for the SNES core. So it's like there's three
bsnes-accuracy PPU threads running just for video.

-----

Oh, just a fair warning ... the hooks for the SGB are a work in
progress.

If anyone is working on higan or a fork and want to do something similar
to it, don't use it as a template, at least not yet.

Right now, higan looks like this:

  - Emulator::Video handles the platform→videoRefresh calls
  - Emulator::Audio handles the platform→audioSample calls
  - each core hard-codes the platform→inputPoll, inputRumble calls
  - each core hard-codes calls to path, open, load to process files
  - dipSettings and notify are specialty hacks, neither are even hooked
    up right now to anything

With the SGB, it's an emulation core inside an emulation core, so
ideally you want to hook all of those functions. Emulator::Video and
Emulator::Audio aren't really abstractions over that, as the GB core
calls them and we have to special case not calling them in SGB mode.

The path, open, load can be implemented without hooks, thanks to the UI
only using one instance of Emulator::Platform for all cores. All we have
to do is override the folder path ID for the "Game Boy.sys" folder, so
that it picks "Super Game Boy.sfc/" and loads its boot ROM instead.
That's just a simple argument to GameBoy::System::load() and we're done.

dipSettings, notify and inputRumble don't matter. But we do also have to
hook inputPoll as well.

The nice idea would be for SuperFamicom::ICD2 to inherit from
Emulator::Platform and provide the desired functions that we need to
overload. After that, we'd just need the GB core to keep an abstraction
over the global Emulator::platform\* handle, to select between the UI
version and the SFC::ICD2 version.

However ... that doesn't work because of Emulator::Video and
Emulator::Audio. They would also have to gain an abstraction over
Emulator::platform\*, and even worse ... you'd have to constantly swap
between the two so that the SFC core uses the UI, and the GB core uses
the ICD2.

And so, for right now, I'm checking Model::SuperGameBoy() -> bool
everywhere, and choosing between the UI and ICD2 targets that way. And
as such, the ICD2 doesn't really need Emulator::Platform inheritance,
although it certainly could do that and just use the functions it needs.

But the SGB is even weirder, because we need additional new signals
beyond just Emulator::Platform, like joypWrite(), etc.

I'd also like to work on the Emulator::Stream for the SGB core. I don't
see why we can't have the GB core create its own stream, and let the
ICD2 just use that instead. We just have to be careful about the ICD2's
CPU soft reset function, to make sure the GB core's Stream object
remains valid. What I think that needs is a way to release an
Emulator::Stream individually, rather than calling
Emulator::Audio::reset() to do it. They are shared\_pointer objects, so
I think if I added a destructor function to remove it from
Emulator::Audio::streams, then that should work.
2017-01-26 12:06:06 +11:00
Tim Allen bdc100e123 Update to v102r02 release.
byuu says:

Changelog:

  - I caved on the `samples[] = {0.0}` thing, but I'm very unhappy about it
      - if it's really invalid C++, then GCC needs to stop accepting it
        in strict `-std=c++14` mode
  - Emulator::Interface::Information::resettable is gone
  - Emulator::Interface::reset() is gone
  - FC, SFC, MD cores updated to remove soft reset behavior
  - split GameBoy::Interface into GameBoyInterface,
    GameBoyColorInterface
  - split WonderSwan::Interface into WonderSwanInterface,
    WonderSwanColorInterface
  - PCE: fixed off-by-one scanline error [hex_usr]
  - PCE: temporary hack to prevent crashing when VDS is set to < 2
  - hiro: Cocoa: removed (u)int(#) constants; converted (u)int(#)
    types to (u)int_(#)t types
  - icarus: replaced usage of unique with strip instead (so we don't
    mess up frameworks on macOS)
  - libco: added macOS-specific section marker [Ryphecha]

So ... the major news this time is the removal of the soft reset
behavior. This is a major!! change that results in a 100KiB diff file,
and it's very prone to accidental mistakes!! If anyone is up for
testing, or even better -- looking over the code changes between v102r01
and v102r02 and looking for any issues, please do so. Ideally we'll want
to test every NES mapper type and every SNES coprocessor type by loading
said games and power cycling to make sure the games are all cleanly
resetting. It's too big of a change for me to cover there not being any
issues on my own, but this is truly critical code, so yeah ... please
help if you can.

We technically lose a bit of hardware documentation here. The soft reset
events do all kinds of interesting things in all kinds of different
chips -- or at least they do on the SNES. This is obviously not ideal.
But in the process of removing these portions of code, I found a few
mistakes I had made previously. It simplifies resetting the system state
a lot when not trying to have all the power() functions call the reset()
functions to share partial functionality.

In the future, the goal will be to come up with a way to add back in the
soft reset behavior via keyboard binding as with the Master System core.
What's going to have to happen is that the key binding will have to send
a "reset pulse" to every emulated chip, and those chips are going to
have to act independently to power() instead of reusing functionality.
We'll get there eventually, but there's many things of vastly greater
importance to work on right now, so it'll be a while. The information
isn't lost ... we'll just have to pull it out of v102 when we are ready.

Note that I left the SNES reset vector simulation code in, even though
it's not possible to trigger, for the time being.

Also ... the Super Game Boy core is still disconnected. To be honest, it
totally slipped my mind when I released v102 that it wasn't connected
again yet. This one's going to be pretty tricky to be honest. I'm
thinking about making a third GameBoy::Interface class just for SGB, and
coming up with some way of bypassing platform-> calls when in this
mode.
2017-01-23 08:04:26 +11:00
Tim Allen c40e9754bc Update to v102r01 release.
byuu says:

Changelog:

  - MS, MD, PCE: remove controllers from scheduler in destructor
    [hex_usr]
  - PCE: no controller should return all bits set (still causing errant
    key presses when swapping gamepads)
  - PCE: emulate MDR for hardware I/O $0800-$17ff
  - PCE: change video resolution to 1140x242
  - PCE: added tertiary background Vscroll register (secondary cache)
  - PCE: create classes out of VDC VRAM, SATB, CRAM for cleaner access
    and I/O registers
  - PCE: high bits of CRAM read should be set
  - PCE: partially emulated VCE display registers: color frequency, HDS,
    HDW, VDS, VDW
  - PCE: 32-width sprites now split to two 16-width sprites to handle
    overflow properly
  - PCE: hopefully emulated sprite zero hit correctly (it's not well
    documented, and not often used)
  - PCE: trigger line coincidence interrupts during the previous
    scanline's Hblank period
  - tomoko: raise viewport from 320x240 to 326x242 to accommodate PC
    Engine's max resolution
  - nall: workaround for Clang compilation bug that can't figure out
    that a char is an integral data type
2017-01-22 11:33:36 +11:00
Tim Allen 26bd7590ad Update to v101r32 release.
byuu says:

Changelog:

  - SMS: fixed controller connection bug
  - SMS: fixed Z80 reset bug
  - PCE: emulated HuC6280 MMU
  - PCE: emulated HuC6280 RAM
  - PCE: emulated HuCard ROM reading
  - PCE: implemented 178 instructions
  - tomoko: removed "soft reset" functionality
  - tomoko: moved "power cycle" to just above "unload" option

I'm not sure of the exact number of HuC6280 instructions, but it's less
than 260.

Many of the ones I skipped are HuC6280-originals that I don't know how
to emulate just yet.

I'm also really unsure about the zero page stuff. I believe we should be
adding 0x2000 to the addresses to hit page 1, which is supposed to be
mapped to the zero page (RAM). But when I look at turboEMU's source, I
have no clue how the hell it could possibly be doing that. It looks to
be reading from page 0, which is almost always ROM, which would be ...
really weird.

I also don't know if I've emulated the T mode opcodes correctly or not.
The documentation on them is really confusing.
2017-01-14 10:59:38 +11:00
Tim Allen bf90bdfcc8 Update to v101r31 release.
byuu says:

Changelog:

  - converted Emulator::Interface::Bind to Emulator::Platform
  - temporarily disabled SGB hooks
  - SMS: emulated Game Gear palette (latching word-write behavior not
    implemented yet)
  - SMS: emulated Master System 'Reset' button, Game Gear 'Start' button
  - SMS: removed reset() functionality, driven by the mappable input now
    instead
  - SMS: split interface class in two: one for Master System, one for
    Game Gear
  - SMS: emulated Game Gear video cropping to 160x144
  - PCE: started on HuC6280 CPU core—so far only registers, NOP
    instruction has been implemented

Errata:

  - Super Game Boy support is broken and thus disabled
  - if you switch between Master System and Game Gear without
    restarting, bad things happen:
      - SMS→GG, no video output on the GG
      - GG→SMS, no input on the SMS

I'm not sure what's causing the SMS\<-\>GG switch bug, having a hard
time debugging it. Help would be very much appreciated, if anyone's up
for it. Otherwise I'll keep trying to track it down on my end.
2017-01-13 12:15:45 +11:00
Tim Allen 4c3f58150c Update to v101r15 release.
byuu says:

Changelog:

  - added (poorly-named) castable<To, With> template
  - Z80 debugger rewritten to make declaring instructions much simpler
  - Z80 has more instructions implemented; supports displacement on
    (IX), (IY) now
  - added `Processor::M68K::Bus` to mirror `Processor::Z80::Bus`
      - it does add a pointer indirection; so I'm not sure if I want to
        do this for all of my emulator cores ...
2016-09-04 23:51:27 +10:00
Tim Allen d91f3999cc Update to v101r14 release.
byuu says:
Changelog:

  - rewrote the Z80 core to properly handle 0xDD (IX0 and 0xFD (IY)
    prefixes
  - added Processor::Z80::Bus as a new type of abstraction
  - all of the instructions implemented have their proper T-cycle counts
    now
  - added nall/certificates for my public keys

The goal of `Processor::Z80::Bus` is to simulate the opcode fetches being
2-read + 2-wait states; operand+regular reads/writes being 3-read. For
now, this puts the cycle counts inside the CPU core. At the moment, I
can't think of any CPU core where this wouldn't be appropriate. But it's
certainly possible that such a case exists. So this may not be the
perfect solution.

The reason for having it be a subclass of Processor::Z80 instead of
virtual functions for the MasterSystem::CPU core to define is due to
naming conflicts. I wanted the core to say `in(addr)` and have it take
the four clocks. But I also wanted a version of the function that didn't
consume time when called. One way to do that would be for the core to
call `Z80::in(addr)`, which then calls the regular `in(addr)` that goes to
`MasterSystem::CPU::in(addr)`. But I don't want to put the `Z80::`
prefix on all of the opcodes. Very easy to forget it, and then end up not
consuming any time. Another is to use uglier names in the
`MasterSystem::CPU` core, like `read_`, `write_`, `in_`, `out_`, etc. But,
yuck.

So ... yeah, this is an experiment. We'll see how it goes.
2016-09-03 21:26:04 +10:00
Tim Allen 7c96826eb0 Update to v101r13 release.
byuu says:

Changelog:

  - MS: added ms/bus
  - Z80: implemented JP/JR/CP/DI/IM/IN instructions
  - MD/VDP: added window layer emulation
  - MD/controller/gamepad: fixed d2,d3 bits (Altered Beast requires
    this)

The Z80 is definitely a lot nastier than the LR35902. There's a lot of
table duplication with HL→IX→IY; and two of them nest two levels deep
(eg FD CB xx xx), so the design may change as I implement more.
2016-08-27 14:48:21 +10:00
Tim Allen 5df717ff2a Update to v101r12 release.
byuu says:

Changelog:

  - new md/bus/ module for bus reads/writes
      - abstracts byte/word accesses wherever possible (everything but
        RAM; forces all but I/O to word, I/O to byte)
      - holds the system RAM since that's technically not part of the
        CPU anyway
  - added md/controller and md/system/peripherals
  - added emulation of gamepads
  - added stub PSG audio output (silent) to cap the framerate at 60fps
    with audio sync enabled
  - fixed VSRAM reads for plane vertical scrolling (two bugs here: add
    instead of sub; interlave plane A/B)
  - mask nametable read offsets (can't exceed 8192-byte nametables
    apparently)
  - emulated VRAM/VSRAM/CRAM reads from VDP data port
  - fixed sprite width/height size calculations
  - added partial emulation of 40-tile per scanline limitation (enough
    to fix Sonic's title screen)
  - fixed off-by-one sprite range testing
  - fixed sprite tile indexing
  - Vblank happens at Y=224 with overscan disabled
      - unsure what happens when you toggle it between Y=224 and Y=240
        ... probably bad things
  - fixed reading of address register for ADDA, CMPA, SUBA
  - fixed sign extension for MOVEA effect address reads
  - updated MOVEM to increment the read addresses (but not writeback)
    for (aN) mode

With all of that out of the way, we finally have Sonic the Hedgehog
(fully?) playable. I played to stage 1-2 and through the special stage,
at least. EDIT: yeah, we probably need HIRQs for Labyrinth Zone.

Not much else works, of course. Most games hang waiting on the Z80, and
those that don't (like Altered Beast) are still royally screwed. Tons of
features still missing; including all of the Z80/PSG/YM2612.

A note on the perihperals this time around: the Mega Drive EXT port is
basically identical to the regular controller ports. So unlike with the
Famicom and Super Famicom, I'm inheriting the exension port from the
controller class.
2016-08-22 08:11:24 +10:00
Tim Allen f7ddbfc462 Update to v101r11 release.
byuu says:

Changelog:

  - 68K: fixed NEG/NEGX operand order
  - 68K: fixed bug in disassembler that was breaking trace logging
  - VDP: improved sprite rendering (still 100% broken)
  - VDP: added horizontal/vertical scrolling (90% broken)

Forgot:

  - 68K: fix extension word sign bit on indexed modes for disassembler
    as well
  - 68K: emulate STOP properly (use r.stop flag; clear on IRQs firing)

I'm really wearing out fast here. The Genesis documentation is somehow
even worse than Game Boy documentation, but this is a far more complex
system.

It's a massive time sink to sit here banging away at every possible
combination of how things could work, only to see no positive
improvements. Nothing I do seems to get sprites to do a goddamn thing.

squee says the sprite Y field is 10-bits, X field is 9-bits. genvdp says
they're both 10-bits. BlastEm treats them like they're both 10-bits,
then masks off the upper bit so it's effectively 9-bits anyway.

Nothing ever bothers to tell you whether the horizontal scroll values
are supposed to add or subtract from the current X position. Probably
the most basic detail you could imagine for explaining horizontal
scrolling and yet ... nope. Nothing.

I can't even begin to understand how the VDP FIFO functionality works,
or what the fuck is meant by "slots".

I'm completely at a loss as how how in the holy hell the 68K works with
8-bit accesses. I don't know whether I need byte/word handlers for every
device, or if I can just hook it right into the 68K core itself. This
one's probably the most major design detail. I need to know this before
I go and implement the PSG/YM2612/IO ports-\>gamepads/Z80/etc.

Trying to debug the 68K is murder because basically every game likes to
start with a 20,000,000-instruction reset phase of checksumming entire
games, and clearing out the memory as agonizingly slowly as humanly
possible. And like the ARM, there's too many registers so I'd need three
widescreen monitors to comfortably view the entire debugger output lines
onscreen.

I can't get any test ROMs to debug functionality outside of full games
because every **goddamned** test ROM coder thinks it's acceptable to tell
people to go fetch some toolchain from a link that died in the late '90s
and only works on MS-DOS 6.22 to build their fucking shit, because god
forbid you include a 32KiB assembled ROM image in your fucking archives.

... I may have to take a break for a while. We'll see.
2016-08-21 12:50:05 +10:00
Tim Allen 0b70a01b47 Update to v101r10 release.
byuu says:
Changelog:

  - 68K: MOVEQ is 8-bit signed
  - 68K: disassembler was print EOR for OR instructions
  - 68K: address/program-counter indexed mode had the signed-word/long
    bit backward
  - 68K: ADDQ/SUBQ #n,aN always works in long mode; regardless of size
  - 68K→VDP DMA needs to use `mode.bit(0)<<22|dmaSource`; increment by
    one instead of two
  - Z80: added registers and initial two instructions
  - MS: hooked up enough to load and start running games
      - Sonic the Hedgehog can execute exactly one instruction... whoo.
2016-08-20 00:11:26 +10:00
Tim Allen 4d2e17f9c0 Update to v101r09 release.
byuu says:

Sorry, two WIPs in one day. Got excited and couldn't wait.

Changelog:

  - ADDQ, SUBQ shouldn't update flags when targeting an address register
  - ADDA should sign extend effective address reads
  - JSR was pushing the PC too early
  - some improvements to 8-bit register reads on the VDP (still needs
    work)
  - added H/V counter reads to the VDP IO port region
  - icarus: added support for importing Master System and Game Gear ROMs
  - tomoko: added library sub-menus for each manufacturer
      - still need to sort Game Gear after Mega Drive somehow ...

The sub-menu system actually isn't all that bad. It is indeed a bit more
annoying, but not as annoying as I thought it was going to be. However,
it looks a hell of a lot nicer now.
2016-08-18 08:05:50 +10:00
Tim Allen 043f6a8b33 Update to v101r08 release.
byuu says:

Changelog:

  - 68K: fixed read-modify-write instructions
  - 68K: fixed ADDX bug (using wrong target)
  - 68K: fixed major bug with SUB using wrong argument ordering
  - 68K: fixed sign extension when reading address registers from
    effective addressing
  - 68K: fixed sign extension on CMPA, SUBA instructions
  - VDP: improved OAM sprite attribute table caching behavior
  - VDP: improved DMA fill operation behavior
  - added Master System / Game Gear stubs (needed for developing the Z80
    core)
2016-08-17 22:31:22 +10:00
Tim Allen ffd150735b Update to v101r07 release.
byuu says:

Added VDP sprite rendering. Can't get any games far enough in to see if
it actually works. So in other words, it doesn't work at all and is 100%
completely broken.

Also added 68K exceptions and interrupts. So far only the VDP interrupt
is present. It definitely seems to be firing in commercial games, so
that's promising. But the implementation is almost certainly completely
wrong. There is fuck all of nothing for documentation on how interrupts
actually work. I had to find out the interrupt vector numbers from
reading the comments from the Sonic the Hedgehog disassembly. I have
literally no fucking clue what I0-I2 (3-bit integer priority value in
the status register) is supposed to do. I know that Vblank=6, Hblank=4,
Ext(gamepad)=2. I know that at reset, SR.I=7. I don't know if I'm
supposed to block interrupts when I is >, >=, <, <= to the interrupt
level. I don't know what level CPU exceptions are supposed to be.

Also implemented VDP regular DMA. No idea if it works correctly since
none of the commercial games run far enough to use it. So again, it's
horribly broken for usre.

Also improved VDP fill mode. But I don't understand how it takes
byte-lengths when the bus is 16-bit. The transfer times indicate it's
actually transferring at the same speed as the 68K->VDP copy, strongly
suggesting it's actually doing 16-bit transfers at a time. In which case,
what happens when you set an odd transfer length?

Also, both DMA modes can now target VRAM, VSRAM, CRAM. Supposedly there's
all kinds of weird shit going on when you target VSRAM, CRAM with VDP
fill/copy modes, but whatever. Get to that later.

Also implemented a very lazy preliminary wait mechanism to to stall out
a processor while another processor exerts control over the bus. This
one's going to be a major work in progress. For one, it totally breaks
the model I use to do save states with libco. For another, I don't
know if a 68K->VDP DMA instantly locks the CPU, or if it the CPU could
actually keep running if it was executing out of RAM when it started
the DMA transfer from ROM (eg it's a bus busy stall, not a hard chip
stall.) That'll greatly change how I handle the waiting.

Also, the OSS driver now supports Audio::Latency. Sound should be
even lower latency now. On FreeBSD when set to 0ms, it's absolutely
incredible. Cannot detect latency whatsoever. The Mario jump sound seems
to happen at the very instant I hear my cherry blue keyswitch activate.
2016-08-15 14:56:38 +10:00
Tim Allen 427bac3011 Update to v101r06 release.
byuu says:

I reworked the video sizing code. Ended up wasting five fucking hours
fighting GTK. When you call `gtk_widget_set_size_request`, it doesn't
actually happen then. This is kind of a big deal because when I then go
to draw onto the viewport, the actual viewport child window is still the
old size, so the image gets distorted. It recovers in a frame or so with
emulation, but if we were to put a still image on there, it would stay
distorted.

The first thought is, `while(gtk_events_pending())
gtk_main_iteration_do(false);` right after the `set_size_request`. But
nope, it tells you there's no events pending. So then you think, go
deeper, use `XPending()` instead. Same thing, GTK hasn't actually issued
the command to Xlib yet. So then you think, if the widget is realized,
just call a blocking `gtk_main_iteration`. One call does nothing, two
calls results in a deadlock on the second one ... do it before program
startup, and the main window will never appear. Great.

Oh, and it's not just the viewport. It's also the widget container area
of the windows, as well as the window itself, as well as the fullscreen
mode toggle effect. They all do this.

For the latter three, I couldn't find anything that worked, so I just
added 20ms loops of constantly calling `gtk_main_iteration_do(false)`
after each one of those things. The downside here is toggling the status
bar takes 40ms, so you'll see it and it'll feel a tiny bit sluggish.

But I can't have a 20ms wait on each widget resize, that would be
catastrophic to performance on windows with lots of widgets.

I tried hooking configure-event and size-allocate, but they were very
unreliable. So instead I ended up with a loop that waits up to a maximm
of 20ms that inspects the `widget->allocation.(width,height)` values
directly and waits for them to be what we asked for with
`set_size_request`.

There was some extreme ugliness in GTK with calling
`gtk_main_iteration_do` recursively (`hiro::Widget::setGeometry` is
called recursively), so I had to lock it to only happen on the top level
widgets (the child ones should get resized while waiting on the
top-level ones, so it should be fine in practice), and also only run it
on realized widgets.

Even still, I'm getting ~3 timeouts when opening the settings dialog in
higan, but no other windows. But, this is the best I can do for now.

And the reason for all of this pain? Yeah, updated the video code.

So the Emulator::Interface now has this:

    struct VideoSize { uint width, height; };  //or requiem for a tuple
    auto videoSize() -> VideoSize;
    auto videoSize(uint width, uint height, bool arc) -> VideoSize;

The first function, for now, is just returning the literal surface size.
I may remove this ... one thing I want to allow for is cores that send
different texture sizes based on interlace/hires/overscan/etc settings.

The second function is more interesting. Instead of having the UI trying
to figure out sizing, I figure the emulation cores can do a better job
and we can customize it per-core now. So it gets the window's width and
height, and whether the user asked for aspect correction, and then
computes the best width/height ratio possible. For now they're all just
doing multiples of a 1x scale to the UI 2x,3x,4x modes.

We still need a third function, which will probably be what I repurpose
videoSize() for: to return the 'effective' size for pixel shaders, to
then feed into ruby, to then feed into quark, to then feed into our
shaders. Since shaders use normalized coordinates for pixel fetching,
this should work out just fine. The real texture size will be exposed to
quark shaders as well, of course.

Now for the main window ... it's just hard-coded to be 640x480, 960x720,
1280x960 for now. It works nicely for some cores on some modes, not so
much for others. Work in progress I guess.

I also took the opportunity to draw the about dialog box logo on the
main window. Got a bit fancy and used the old spherical gradient and
impose functionality of nall/image on it. Very minor highlight, nothing
garish. Just something nicer than a solid black window.

If you guys want to mess around with sizes, placements, and gradient
styles/colors/shapes ... feel free. If you come up with something nicer,
do share.

That's what led to all the GTK hell ... the logo wasn't drawing right as
you resized the window. But now it is, though I am not at all happy with
the hacking I had to do.

I also had to improve the video update code as a result of this:

  - when you unload a game, it blacks out the screen
      - if you are not quitting the emulator, it'll draw the logo; if
        you are, it won't
  - when you load a game, it black out the logo

These options prevent any unsightliness from resizing the viewport with
image data on it already

I need to redraw the logo when toggling fullscreen with no game loaded
as well for Windows, it seems.
2016-08-15 14:52:05 +10:00
Tim Allen ac2d0ba1cf Update to v101r05 release.
byuu says:

Changelog:

  - 68K: fixed bug that affected BSR return address
  - VDP: added very preliminary emulation of planes A, B, W (W is
    entirely broken though)
  - VDP: added command/address stuff so you can write to VRAM, CRAM,
    VSRAM
  - VDP: added VRAM fill DMA

I would be really surprised if any commercial games showed anything at
all, so I'd probably recommend against wasting your time trying, unless
you're really bored :P

Also, I wanted to add: I am accepting patches\! So if anyone wants to
look over the 68K core for bugs, that would save me untold amounts of
time in the near future :D
2016-08-13 09:47:30 +10:00
Tim Allen 1df2549d18 Update to v101r04 release.
byuu says:

Changelog:

  - pulled the (u)intN type aliases into higan instead of leaving them
    in nall
  - added 68K LINEA, LINEF hooks for illegal instructions
  - filled the rest of the 68K lambda table with generic instance of
    ILLEGAL
  - completed the 68K disassembler effective addressing modes
      - still unsure whether I should use An to decode absolute
        addresses or not
      - pro: way easier to read where accesses are taking place
      - con: requires An to be valid; so as a disassembler it does a
        poor job
      - making it optional: too much work; ick
  - added I/O decoding for the VDP command-port registers
  - added skeleton timing to all five processor cores
  - output at 1280x480 (needed for mixed 256/320 widths; and to handle
    interlace modes)

The VDP, PSG, Z80, YM2612 are all stepping one clock at a time and
syncing; which is the pathological worst case for libco. But they also
have no logic inside of them. With all the above, I'm averaging around
250fps with just the 68K core actually functional, and the VDP doing a
dumb "draw white pixels" loop. Still way too early to tell how this
emulator is going to perform.

Also, the 320x240 mode of the Genesis means that we don't need an aspect
correction ratio. But we do need to ensure the output window is a
multiple 320x240 so that the scale values work correctly. I was
hard-coding aspect correction to stretch the window an additional \*8/7.
But that won't work anymore so ... the main higan window is now 640x480,
960x720, or 1280x960. Toggling aspect correction only changes the video
width inside the window.

It's a bit jarring ... the window is a lot wider, more black space now
for most modes. But for now, it is what it is.
2016-08-12 11:07:04 +10:00
Tim Allen c50723ef61 Update to v100r15 release.
byuu wrote:

Aforementioned scheduler changes added. Longer explanation of why here:
http://hastebin.com/raw/toxedenece

Again, we really need to test this as thoroughly as possible for
regressions :/
This is a really major change that affects absolutely everything: all
emulation cores, all coprocessors, etc.

Also added ADDX and SUB to the 68K core, which brings us just barely
above 50% of the instruction encoding space completed.

[Editor's note: The "aformentioned scheduler changes" were described in
a previous forum post:

    Unfortunately, 64-bits just wasn't enough precision (we were
    getting misalignments ~230 times a second on 21/24MHz clocks), so
    I had to move to 128-bit counters. This of course doesn't exist on
    32-bit architectures (and probably not on all 64-bit ones either),
    so for now ... higan's only going to compile on 64-bit machines
    until we figure something out. Maybe we offer a "lower precision"
    fallback for machines that lack uint128_t or something. Using the
    booth algorithm would be way too slow.

    Anyway, the precision is now 2^-96, which is roughly 10^-29. That
    puts us far beyond the yoctosecond. Suck it, MAME :P I'm jokingly
    referring to it as the byuusecond. The other 32-bits of precision
    allows a 1Hz clock to run up to one full second before all clocks
    need to be normalized to prevent overflow.

    I fixed a serious wobbling issue where I was using clock > other.clock
    for synchronization instead of clock >= other.clock; and also another
    aliasing issue when two threads share a common frequency, but don't
    run in lock-step. The latter I don't even fully understand, but I
    did observe it in testing.

    nall/serialization.hpp has been extended to support 128-bit integers,
    but without explicitly naming them (yay generic code), so nall will
    still compile on 32-bit platforms for all other applications.

    Speed is basically a wash now. FC's a bit slower, SFC's a bit faster.

The "longer explanation" in the linked hastebin is:

    Okay, so the idea is that we can have an arbitrary number of
    oscillators. Take the SNES:

    - CPU/PPU clock = 21477272.727272hz
    - SMP/DSP clock = 24576000hz
    - Cartridge DSP1 clock = 8000000hz
    - Cartridge MSU1 clock = 44100hz
    - Controller Port 1 modem controller clock = 57600hz
    - Controller Port 2 barcode battler clock = 115200hz
    - Expansion Port exercise bike clock = 192000hz

    Is this a pathological case? Of course it is, but it's possible. The
    first four do exist in the wild already: see Rockman X2 MSU1
    patch. Manifest files with higan let you specify any frequency you
    want for any component.

    The old trick higan used was to hold an int64 counter for each
    thread:thread synchronization, and adjust it like so:

    - if thread A steps X clocks; then clock += X * threadB.frequency
      - if clock >= 0; switch to threadB
    - if thread B steps X clocks; then clock -= X * threadA.frequency
      - if clock <  0; switch to threadA

    But there are also system configurations where one processor has to
    synchronize with more than one other processor. Take the Genesis:

    - the 68K has to sync with the Z80 and PSG and YM2612 and VDP
    - the Z80 has to sync with the 68K and PSG and YM2612
    - the PSG has to sync with the 68K and Z80 and YM2612

    Now I could do this by having an int64 clock value for every
    association. But these clock values would have to be outside the
    individual Thread class objects, and we would have to update every
    relationship's clock value. So the 68K would have to update the Z80,
    PSG, YM2612 and VDP clocks. That's four expensive 64-bit multiply-adds
    per clock step event instead of one.

    As such, we have to account for both possibilities. The only way to
    do this is with a single time base. We do this like so:

    - setup: scalar = timeBase / frequency
    - step: clock += scalar * clocks

    Once per second, we look at every thread, find the smallest clock
    value. Then subtract that value from all threads. This prevents the
    clock counters from overflowing.

    Unfortunately, these oscillator values are psychotic, unpredictable,
    and often times repeating fractions. Even with a timeBase of
    1,000,000,000,000,000,000 (one attosecond); we get rounding errors
    every ~16,300 synchronizations. Specifically, this happens with a CPU
    running at 21477273hz (rounded) and SMP running at 24576000hz. That
    may be good enough for most emulators, but ... you know how I am.

    Plus, even at the attosecond level, we're really pushing against the
    limits of 64-bit integers. Given the reciprocal inverse, a frequency
    of 1Hz (which does exist in higan!) would have a scalar that consumes
    1/18th of the entire range of a uint64 on every single step. Yes, I
    could raise the frequency, and then step by that amount, I know. But
    I don't want to have weird gotchas like that in the scheduler core.

    Until I increase the accuracy to about 100 times greater than a
    yoctosecond, the rounding errors are too great. And since the only
    choice above 64-bit values is 128-bit values; we might as well use
    all the extra headroom. 2^-96 as a timebase gives me the ability to
    have both a 1Hz and 4GHz clock; and run them both for a full second;
    before an overflow event would occur.

Another hastebin includes demonstration code:

    #include <libco/libco.h>

    #include <nall/nall.hpp>
    using namespace nall;

    //

    cothread_t mainThread = nullptr;
    const uint iterations = 100'000'000;
    const uint cpuFreq = 21477272.727272 + 0.5;
    const uint smpFreq = 24576000.000000 + 0.5;
    const uint cpuStep = 4;
    const uint smpStep = 5;

    //

    struct ThreadA {
      cothread_t handle = nullptr;
      uint64 frequency = 0;
      int64 clock = 0;

      auto create(auto (*entrypoint)() -> void, uint frequency) {
        this->handle = co_create(65536, entrypoint);
        this->frequency = frequency;
        this->clock = 0;
      }
    };

    struct CPUA : ThreadA {
      static auto Enter() -> void;
      auto main() -> void;
      CPUA() { create(&CPUA::Enter, cpuFreq); }
    } cpuA;

    struct SMPA : ThreadA {
      static auto Enter() -> void;
      auto main() -> void;
      SMPA() { create(&SMPA::Enter, smpFreq); }
    } smpA;

    uint8 queueA[iterations];
    uint offsetA;
    cothread_t resumeA = cpuA.handle;

    auto EnterA() -> void {
      offsetA = 0;
      co_switch(resumeA);
    }

    auto QueueA(uint value) -> void {
      queueA[offsetA++] = value;
      if(offsetA >= iterations) {
        resumeA = co_active();
        co_switch(mainThread);
      }
    }

    auto CPUA::Enter() -> void { while(true) cpuA.main(); }

    auto CPUA::main() -> void {
      QueueA(1);
      smpA.clock -= cpuStep * smpA.frequency;
      if(smpA.clock < 0) co_switch(smpA.handle);
    }

    auto SMPA::Enter() -> void { while(true) smpA.main(); }

    auto SMPA::main() -> void {
      QueueA(2);
      smpA.clock += smpStep * cpuA.frequency;
      if(smpA.clock >= 0) co_switch(cpuA.handle);
    }

    //

    struct ThreadB {
      cothread_t handle = nullptr;
      uint128_t scalar = 0;
      uint128_t clock = 0;

      auto print128(uint128_t value) {
        string s;
        while(value) {
          s.append((char)('0' + value % 10));
          value /= 10;
        }
        s.reverse();
        print(s, "\n");
      }

      //femtosecond (10^15) =    16306
      //attosecond  (10^18) =   688838
      //zeptosecond (10^21) = 13712691
      //yoctosecond (10^24) = 13712691 (hitting a dead-end on a rounding error causing a wobble)
      //byuusecond? ( 2^96) = (perfect? 79,228 times more precise than a yoctosecond)

      auto create(auto (*entrypoint)() -> void, uint128_t frequency) {
        this->handle = co_create(65536, entrypoint);

        uint128_t unitOfTime = 1;
      //for(uint n : range(29)) unitOfTime *= 10;
        unitOfTime <<= 96;  //2^96 time units ...

        this->scalar = unitOfTime / frequency;
        print128(this->scalar);
        this->clock = 0;
      }

      auto step(uint128_t clocks) -> void { clock += clocks * scalar; }
      auto synchronize(ThreadB& thread) -> void { if(clock >= thread.clock) co_switch(thread.handle); }
    };

    struct CPUB : ThreadB {
      static auto Enter() -> void;
      auto main() -> void;
      CPUB() { create(&CPUB::Enter, cpuFreq); }
    } cpuB;

    struct SMPB : ThreadB {
      static auto Enter() -> void;
      auto main() -> void;
      SMPB() { create(&SMPB::Enter, smpFreq); clock = 1; }
    } smpB;

    auto correct() -> void {
      auto minimum = min(cpuB.clock, smpB.clock);
      cpuB.clock -= minimum;
      smpB.clock -= minimum;
    }

    uint8 queueB[iterations];
    uint offsetB;
    cothread_t resumeB = cpuB.handle;

    auto EnterB() -> void {
      correct();
      offsetB = 0;
      co_switch(resumeB);
    }

    auto QueueB(uint value) -> void {
      queueB[offsetB++] = value;
      if(offsetB >= iterations) {
        resumeB = co_active();
        co_switch(mainThread);
      }
    }

    auto CPUB::Enter() -> void { while(true) cpuB.main(); }

    auto CPUB::main() -> void {
      QueueB(1);
      step(cpuStep);
      synchronize(smpB);
    }

    auto SMPB::Enter() -> void { while(true) smpB.main(); }

    auto SMPB::main() -> void {
      QueueB(2);
      step(smpStep);
      synchronize(cpuB);
    }

    //

    #include <nall/main.hpp>
    auto nall::main(string_vector) -> void {
      mainThread = co_active();

      uint masterCounter = 0;
      while(true) {
        print(masterCounter++, " ...\n");

        auto A = clock();
        EnterA();
        auto B = clock();
        print((double)(B - A) / CLOCKS_PER_SEC, "s\n");

        auto C = clock();
        EnterB();
        auto D = clock();
        print((double)(D - C) / CLOCKS_PER_SEC, "s\n");

        for(uint n : range(iterations)) {
          if(queueA[n] != queueB[n]) return print("fail at ", n, "\n");
        }
      }
    }

...and that's everything.]
2016-07-31 12:11:20 +10:00
Tim Allen ca277cd5e8 Update to v100r14 release.
byuu says:

(Windows: compile with -fpermissive to silence an annoying error. I'll
fix it in the next WIP.)

I completely replaced the time management system in higan and overhauled
the scheduler.

Before, processor threads would have "int64 clock"; and there would
be a 1:1 relationship between two threads. When thread A ran for X
cycles, it'd subtract X * B.Frequency from clock; and when thread B ran
for Y cycles, it'd add Y * A.Frequency from clock. This worked well
and allowed perfect precision; but it doesn't work when you have more
complicated relationships: eg the 68K can sync to the Z80 and PSG; the
Z80 to the 68K and PSG; so the PSG needs two counters.

The new system instead uses a "uint64 clock" variable that represents
time in attoseconds. Every time the scheduler exits, it subtracts
the smallest clock count from all threads, to prevent an overflow
scenario. The only real downside is that rounding errors mean that
roughly every 20 minutes, we have a rounding error of one clock cycle
(one 20,000,000th of a second.) However, this only applies to systems
with multiple oscillators, like the SNES. And when you're in that
situation ... there's no such thing as a perfect oscillator anyway. A
real SNES will be thousands of times less out of spec than 1hz per 20
minutes.

The advantages are pretty immense. First, we obviously can now support
more complex relationships between threads. Second, we can build a
much more abstracted scheduler. All of libco is now abstracted away
completely, which may permit a state-machine / coroutine version of
Thread in the future. We've basically gone from this:

    auto SMP::step(uint clocks) -> void {
      clock += clocks * (uint64)cpu.frequency;
      dsp.clock -= clocks;
      if(dsp.clock < 0 && !scheduler.synchronizing()) co_switch(dsp.thread);
      if(clock >= 0 && !scheduler.synchronizing()) co_switch(cpu.thread);
    }

To this:

    auto SMP::step(uint clocks) -> void {
      Thread::step(clocks);
      synchronize(dsp);
      synchronize(cpu);
    }

As you can see, we don't have to do multiple clock adjustments anymore.
This is a huge win for the SNES CPU that had to update the SMP, DSP, all
peripherals and all coprocessors. Likewise, we don't have to synchronize
all coprocessors when one runs, now we can just synchronize the active
one to the CPU.

Third, when changing the frequencies of threads (think SGB speed setting
modes, GBC double-speed mode, etc), it no longer causes the "int64
clock" value to be erroneous.

Fourth, this results in a fairly decent speedup, mostly across the
board. Aside from the GBA being mostly a wash (for unknown reasons),
it's about an 8% - 12% speedup in every other emulation core.

Now, all of this said ... this was an unbelievably massive change, so
... you know what that means >_> If anyone can help test all types of
SNES coprocessors, and some other system games, it'd be appreciated.

----

Lastly, we have a bitchin' new about screen. It unfortunately adds
~200KiB onto the binary size, because the PNG->C++ header file
transformation doesn't compress very well, and I want to keep the
original resource files in with the higan archive. I might try some
things to work around this file size increase in the future, but for now
... yeah, slightly larger archive sizes, sorry.

The logo's a bit busted on Windows (the Label control's background
transparency and alignment settings aren't working), but works well on
GTK. I'll have to fix Windows before the next official release. For now,
look on my Twitter feed if you want to see what it's supposed to look
like.

----

EDIT: forgot about ICD2::Enter. It's doing some weird inverse
run-to-save thing that I need to implement support for somehow. So, save
states on the SGB core probably won't work with this WIP.
2016-07-30 13:56:12 +10:00
Tim Allen f230d144b5 Update to v100r12 release.
byuu says:

All of the above fixes, plus I added all 24 variations on the shift
opcodes, plus SUBQ, plus fixes to the BCC instruction.

I can now run 851,767 instructions into Sonic the Hedgehog before hitting
an unimplemented instruction (SUB).

The 68K core is probably only ~35% complete, and yet it's already within
4KiB of being the largest CPU core, code size wise, in all of higan. Fuck
this chip.
2016-07-25 23:15:54 +10:00
Tim Allen 7ccfbe0206 Update to v100r11 release.
byuu says:

I split the Register class and read/write handlers into DataRegister and
AddressRegister, given that they have different behaviors on byte/word
accesses (data tends to preserve the upper bits; address tends to
sign-extend things.)

I expanded EA to EffectiveAddress. No sense in abbreviating things
to death.

I've now implemented 26 instructions. But the new ones are just all the
stupid from/to ccr/sr instructions.

Ryphecha confirmed that you can't set the undefined bits, so I don't
think the BitField concept is appropriate for the CCR/SR. Instead, I'm
just storing direct flags and have (read,write)(CCR,SR) instead. This
isn't like the 65816 where you have subroutines that push and pop the
flag register. It's much more common to access individual flags. Doesn't
match the consistency angle of the other CPU cores, but ... I think this
is the right thing to for the 68K specifically.
2016-07-23 12:32:35 +10:00
Tim Allen 4b897ba791 Update to v100r10 release.
byuu says:

Redesigned the handling of reading/writing registers to be about eight
times faster than the old system. More work may be needed ... it seems
data registers tend to preserve their upper bits upon assignment; whereas
address registers tend to sign-extend values into them. It may make
sense to have DataRegister and AddressRegister classes with separate
read/write handlers. I'd have to hold two Register objects inside the
EffectiveAddress (EA) class if we do that.

Implemented 19 opcodes now (out of somewhere between 60 and 90.) That gets
the first ~530,000 instructions in Sonic the Hedgehog running (though
probably wrong. But we can run a lot thanks to large initialization
loops.)

If I force the core to loop back to the reset vector on an invalid opcode,
I'm getting about 1500fps with a dumb 320x240 blit 60 times a second and
just the 68K running alone (no Z80, PSG, VDP, YM2612.) I don't know if
that's good or not. I guess we'll find out.

I had to stop tonight because the final opcode I execute is an RTS
(return from subroutine) that's branching back to address 0; which is
invalid ... meaning something went terribly wrong and the system crashed.
2016-07-22 22:03:25 +10:00
Tim Allen be3f6ac0d5 Update to v100r09 release.
byuu says:

Another six hours in ...

I have all of the opcodes, memory access functions, disassembler mnemonics
and table building converted over to the new template<uint Size> format.

Certainly, it would be quite easy for this nightmare chip to throw me
another curveball, but so far I can handle:

- MOVE (EA to, EA from) case
  - read(from) has to update register index for +/-(aN) mode
- MOVEM (EA from) case
  - when using +/-(aN), RA can't actually be updated until the transfer
    is completed
- LEA (EA from) case
  - doesn't actually perform the final read; just returns the address
    to be read from
- ANDI (EA from-and-to) case
  - same EA has to be read from and written to
  - for -(aN), the read has to come from aN-2, but can't update aN yet;
    so that the write also goes to aN-2
- no opcode can ever fetch the extension words more than once
- manually control the order of extension word fetching order for proper
  opcode decoding

To do all of that without a whole lot of duplicated code (or really
bloating out every single instruction with red tape), I had to bring
back the "bool valid / uint32 address" variables inside the EA struct =(

If weird exceptions creep in like timing constraints only on certain
opcodes, I can use template flags to the EA read/write functions to
handle that.
2016-07-19 19:12:05 +10:00
Tim Allen 059347e575 Update to v100r07 release.
byuu says:

Four and a half hours of work and ... zero new opcodes implemented.

This was the best job I could do refining the effective address
computations. Should have all twelve 68000 modes implemented now. Still
have a billion questions about when and how I'm supposed to perform
certain edge case operations, though.
2016-07-17 13:24:28 +10:00
Tim Allen 1c0ef793fe Update to v100r04 release.
byuu says:

I now have enough of three instructions implemented to get through the
first four instructions in Sonic the Hedgehog.

But they're far from complete. The very first instruction uses EA
addressing, which is similar to x86's ModRM in terms of how disgustingly
complex it is. And it also accesses Z80 control registers, which obviously
isn't going to do anything yet.

The slow speed was me being stupid again. It's not 7.6MHz per frame,
it's 7.67MHz per second. So yeah, speed is so far acceptable again. But
we'll see how things go as I keep emulating more. The 68K decode is not
pretty at all.
2016-07-12 20:19:31 +10:00
Tim Allen 76a8ecd32a Update to v100r03 release.
byuu says:

Changelog:
- moved Thread, Scheduler, Cheat functionality into emulator/ for
  all cores
- start of actual Mega Drive emulation (two 68K instructions)

I'm going to be rather terse on MD emulation, as it's too early for any
meaningful dialogue here.
2016-07-10 15:28:26 +10:00
Tim Allen 3dd1aa9c1b Update to v100r02 release.
byuu says:

Sigh ... I'm really not a good person. I'm inherently selfish.

My responsibility and obligation right now is to work on loki, and
then on the Tengai Makyou Zero translation, and then on improving the
Famicom emulation.

And yet ... it's not what I really want to do. That shouldn't matter;
I should work on my responsibilities first.

Instead, I'm going to be a greedy, self-centered asshole, and work on
what I really want to instead.

I'm really sorry, guys. I'm sure this will make a few people happy,
and probably upset even more people.

I'm also making zero guarantees that this ever gets finished. As always,
I wish I could keep these things secret, so if I fail / give up, I could
just drop it with no shame. But I would have to cut everyone out of the
WIP process completely to make it happen. So, here goes ...

This WIP adds the initial skeleton for Sega Mega Drive / Genesis
emulation. God help us.

(minor note: apparently the new extension for Mega Drive games is .md,
neat. That's what I chose for the folders too. I thought it was .smd,
so that'll be fixed in icarus for the next WIP.)

(aside: this is why I wanted to get v100 out. I didn't want this code in
a skeleton state in v100's source. Nor did I want really broken emulation,
which the first release is sure to be, tarring said release.)

...

So, basically, I've been ruminating on the legacy I want to leave behind
with higan. 3D systems are just plain out. I'm never going to support
them. They're too complex for my abilities, and they would run too slowly
with my design style. I'm not willing to compromise my design ideals. And
I would never want to play a 3D game system at native 240p/480i resolution
... but 1080p+ upscaling is not accurate, so that's a conflict I want
to avoid entirely. It's also never going to emulate computer systems
(X68K, PC-98, FM-Towns, etc) because holy shit that would completely
destroy me. It's also never going emulate arcade machines.

So I think of higan as a collection of 2D emulators for consoles
and handhelds. I've gone over every major 2D gaming system there is,
looking for ones with games I actually care about and enjoy. And I
basically have five of those systems supported already. Looking at the
remaining list, I see only three systems left that I have any interest
in whatsoever: PC-Engine, Master System, Mega Drive. Again, I'm not in
any way committing to emulating any of these, but ... if I had all of
those in higan, I think I'd be content to really, truly, finally stop
writing more emulators for the rest of my life.

And so I decided to tackle the most difficult system first. If I'm
successful, the Z80 core should cover a lot of the work on the SMS. And
the HuC6280 should land somewhere between the NES and SNES in terms of
difficulty ... closer to the NES.

The systems that just don't appeal to me at all, which I will never touch,
include, but are not limited to:
* Atari 2600/5200/7800
* Lynx
* Jaguar
* Vectrex
* Colecovision
* Commodore 64
* Neo-Geo
* Neo-Geo Pocket / Color
* Virtual Boy
* Super A'can
* 32X
* CD-i
* etc, etc, etc.

And really, even if something were mildly interesting in there ... we
have to stop. I can't scale infinitely. I'm already way past my limit,
but I'm doing this anyway. Too many cores bloats everything and kills
quality on everything. I don't want higan to become MESS v2.

I don't know what I'll do about the Famicom Disk System, PC-Engine CD,
and Mega CD. I don't think I'll be able to achieve 60fps emulating the
Mega CD, even if I tried to.

I don't know what's going to happen here with even the Mega Drive. Maybe
I'll get driven crazy with the documentation and quit. Maybe it'll end
up being too complicated and I'll quit. Maybe the emulation will end up
way too slow and I'll give up. Maybe it'll take me seven years to get
any games playable at all. Maybe Steve Snake, AamirM and Mike Pavone
will pool money to hire a hitman to come after me. Who knows.

But this is what I want to do, so ... here goes nothing.
2016-07-09 14:21:37 +10:00