mirror of https://github.com/bsnes-emu/bsnes.git
8 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Tim Allen
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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.
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Tim Allen
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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. |
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Tim Allen
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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.
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Tim Allen
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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.
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Tim Allen
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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.
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Tim Allen
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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.
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Tim Allen
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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.
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Tim Allen
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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. |