byuu says:
Changelog:
- nall/GNUmakefile: fixed findstring parameter arguments [Screwtape]
- nall/Windows: always include -mthreads -lpthread for all
applications
- nall/memory: code restructuring
I really wanted to work on the new PPU today, but I thought I'd spend a
few minutes making some minor improvements to nall::memory, that was
five and a half hours ago. Now I have a 67KiB diff of changes. Sigh.
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.
byuu says:
Changelog:
- PCE: emulated PSG volume controls (vastly enhances audio quality)
- PCE: emulated PSG noise as a square wave (somewhat enhances audio
quality)
- PCE: added save state support (currently broken and deadlocks the
emulator though)
Thankfully, MAME had some rather easy to read code on how the volume
adjustment works, which they apparently ripped out of expired patents.
Hooray!
The two remaining sound issues are:
1. the random number generator for the noise channel is definitely not
hardware accurate. But it won't affect the sound quality at all. You'd
only be able to tell the difference by looking at hex bytes of a stream
rip.
2. I have no clue how to emulate the LFO (frequency modulation). A comment
in MAME's code (they also don't emulate it) advises that they aren't
aware of any games that even use it. But I'm there has to be at least one?
Given LFO not being used, and the RNG not really mattering all that much
... the sound's pretty close to perfect now.
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.
byuu says:
Changelog:
- PCE: split VCE from VDC
- HuC6280: changed bus from (uint21 addr) to (uint8 bank, uint13 addr)
- added SuperGrafx emulation (adds secondary VDC, plus new VPC)
The VDC now has no concept of the actual display raster timing, and
instead is driven by Vpulse (start of frame) and Hpulse (start of
scanline) signals from the VCE. One still can't render the start of the
next scanline onto the current scanline through overly aggressive
timings, but it shouldn't be too much more difficult to allow that to
occur now. This process incurs quite a major speed hit, so low-end
systems with Atom CPUs can't run things at 60fps anymore.
The timing needs a lot of work. The pixels end up very jagged if the VCE
doesn't output batches of 2-4 pixels at a time. But this should not be a
requirement at all, so I'm not sure what's going wrong there.
Yo, Bro and the 512-width mode of TV Sports Basketball is now broken as
a result of these changes, and I'm not sure why.
To load SuperGrafx games, you're going to have to change the .pce
extensions to .sg or .sgx. Or you can manually move the games from the
PC Engine folder to the SuperGrafx folder and change the game folder
extensions. I have no way to tell the games apart. Mednafen uses CRC32
comparisons, and I may consider that since there's only five games, but
I'm not sure yet.
The only SuperGrafx game that's playable right now is Aldynes. And the
priorities are all screwed up. I don't understand how the windows or the
priorities work at all from sgxtech.txt, so ... yeah. It's pretty
broken, but it's a start.
I could really use some help with this, as I'm very lost right now with
rendering :/
-----
Note that the SuperGrafx is technically its own system, it's not an
add-on.
As such, I'm giving it a separate .sys folder, and a separate library.
There's debate over how to name this thing. "SuperGrafx" appears more
popular than "Super Grafx". And you might also call it the "PC Engine
SuperGrafx", but I decided to leave off the prefix so it appears more
distinct.
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
byuu says:
Changelog:
- PCE: emulated gamepad polling
- PCE: emulated CPU interrupt sources
- PCE: emulated timer
- PCE: smarter emulation of ST0,ST1,ST2 instructions
- PCE: better structuring of CPU, VDP IO registers
- PCE: connected palette generation to the interface
- PCE: emulated basic VDC timing
- PCE: emulated VDC Vblank, Coincidence, and DMA completion IRQs
- PCE: emulated VRAM, SATB DMA transfers
- PCE: emulated VDC I/O registers
Everything I've implemented today likely has lots of bugs, and is
untested for obvious reasons.
So basically, after I fix many horrendous bugs, it should now be
possible to implement the VDC and start getting graphical output.
byuu says:
Changelog:
- PCE: HuC6280 core completed
There's bound to be a countless stream of bugs, and the cycle counts are
almost certainly not exact yet, but ... all instructions are implemented.
So at this point, I can start comparing trace logs against Mednafen's
debugger output.
Of course, we're very likely to immediately slam into a wall of needing
I/O registers implemented for the VDC in order to proceed further.
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.
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.
byuu says:
Changelog:
- SMS: added cartridge ROM/RAM mirroring (fixes Alex Kidd)
- SMS: fixed 8x16 sprite mode (fixes Wonder Boy, Ys graphics)
- Z80: emulated "ex (sp),hl" instruction
- Z80: fixed INx NF (should be set instead of cleared)
- Z80: fixed loop condition check for CPxR, INxR, LDxR, OTxR (fixes
walking in Wonder Boy)
- SFC: removed Debugger and sfc/debugger.hpp
- icarus: connected MS, GG, MD importing to the scan dialog
- PCE: added emulation skeleton to higan and icarus
At this point, Master System games are fairly highly compatible, sans
audio. Game Gear games are running, but I need to crop the resolution
and support the higher color palette that they can utilize. It's really
something else the way they handled the resolution shrink on that thing.
The last change is obviously going to be the biggest news.
I'm very well aware it's not an ideal time to start on a new emulation
core, with the MS and MD cores only just now coming to life with no
audio support.
But, for whatever reason, my heart's really set on working on the PC
Engine. I wanted to write the final higan skeleton core, and get things
ready so that whenever I'm in the mood to work on the PCE, I can do so.
The skeleton is far and away the most tedious and obnoxious part of the
emulator development, because it's basically all just lots of
boilerplate templated code, lots of new files to create, etc.
I really don't know how things are going to proceed ... but I can say
with 99.9% certainty that this will be the final brand new core ever
added to higan -- at least one written by me, that is. This was
basically the last system from my childhood that I ever cared about.
It's the last 2D system with games that I really enjoy playing. No other
system is worth dividing my efforts and reducing the quality and amount
of time to work on the systems I have.
In the future, there will be potential for FDS, Mega CD and PCE-CD
support. But those will all be add-ons, and they'll all be really
difficult and challenge the entire design of higan's UI (it's entirely
cartridge-driven at this time.) None of them will be entirely new cores
like this one.
Tim Allen