Commit Graph

12 Commits

Author SHA1 Message Date
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 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 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 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 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 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 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