Commit Graph

8 Commits

Author SHA1 Message Date
Tim Allen e216912ca3 Update to v106r09 release.
byuu says:

Changelog:

  - higan, icarus, genius: new manifest syntax (work in progress)

Pretty much only LoROM and HiROM SNES games will load right now, and RAM
will only work right if the save.ram file already exists to pull its
file size from (a temporary cheap hack was used.)

Basically, I'm just getting this out there for evaluation.

One minor errata is that I switched icarus to using “memory/battery” to
indicate battery-backed RAM, whereas genius still uses “memory/volatile”
to indicate non-battery-backed RAM.

I intend to make it “memory/battery” in genius, and have the field
auto-enable when RAM or RTC is selected for type (obviously allowing it
to be unchecked for volatile memory.)

I need to update all 64 production boards, and 25 of 29 generic boards,
to use the new slot syntax; and I also need to update every single core
in higan to use the new manifest game syntax. I want to build out a
generic manifest game parser that all emulation cores will use.

Once I finish this, I'll also need to write a database converter to
update all of my licensed game dumps to the new database syntax.

I also need to write up something for doc.byuu.org explaining the new
manifest game syntax. The manifest board syntax will still be “internal”
and subject to revisions, but once v107 is out, the gamepak manifest
format will be set in stone sans extensions.
2018-03-05 15:34:07 +11:00
Tim Allen c49d3b2006 Update to v106r07 release.
byuu says:

Changelog:

  - Super Game Boy: for the 50th time, higan won't segfault if you
    cancel the Game Boy cartridge load request
  - icarus: moved to new manifest syntax for all remaining systems
  - Game Boy: moved to new manifest syntax

Errata:

  - Game Boy: save RAM does not appear to be working for some reason
  - Famicom: higan won't even start to run this system; it just acts
    like a cartridge was never loaded ...
  - cores outside of the Super Famicom and Game Boy/Color will not run
    due to icarus/higan manifest syntax differences
2018-02-21 11:12:09 +11:00
Tim Allen d13f1dd9ea Update to v104r03 release.
byuu says:

Changelog:

  - md/vdp: added full interlace emulation [byuu, Sik, Eke, Mask of
    Destiny]
  - md/vdp: fix an issue with overscan/highlight when setting was
    disabled [hex\_usr]
  - md/vdp: serialize field, and all oam/objects state
  - icarus/md: do not enable RAM unless header 0x1b0-1b1 == "RA"
    [hex\_usr]

I really can't believe how difficult the interlace support was to add. I
must have tried a hundred combinations of adjusting Y, Vscroll, tile
addressing, heights, etc. Many of the changes were a wash that improved
some things, regressed others.

In the end I ended up needing input from three different people to
implement what should have been trivial. I don't know if the Mega Drive
is just that weird, if I've declined that much in skill since the days
when I implemented SNES interlace, or if I've just never been that good.

But either way, I'm disappointed in myself for not being able to figure
either this or shadow/highlight out on my own. Yet I'm extremely
grateful to my friends for helping carry me when I get stuck.

Since it wasn't ever documented before, I'm going to try and document
the changes necessary to implement interlace mode for any future
emudevs.
2017-08-22 19:11:43 +10:00
Tim Allen 366e9cebff Update to v104r01 release.
byuu says:

Changelog:

  - gba/cpu: synchronize to the PPU, not oneself, when the CPU is
    stopped
      - this bug was patched in the official v104 release; but not in
        the .tar.xz archive
  - ms/vdp: backdrop color is on the second 16-entry palette, not the
    first [hex\_usr]
  - ms/vdp: fix background color 0 priority; fixes Alex Kidd in High
    Tech World text boxes [hex\_usr]
  - tomoko: choose first option when loading files via the command-line
    [hex\_usr]
  - icarus: lo/hi RAM addressing was backwards; M68K is big endian;
    fixes save files in Sonic 3

Many thanks to hex\_usr for the Master System / Game Gear VDP fix.
That's a tricky system to get good technical information on. The fix
should be correct, but please report if you spot any regressions just in
case.
2017-08-18 22:48:29 +10:00
Tim Allen ba384a7c48 Update to v104 release.
byuu says:

Changelog:

  - emulator/interface: removed unused Region struct
  - gba/cpu: optimized CPU::step() as much as I could for a slight
    speedup¹
  - gba/cpu: synchronize the APU better during FIFO updates
  - higan/md, icarus: add automatic region detection; make it the
    default option [hex\_usr]
      - picks NTSC-J if there's more than one match ... eventually, this
        will be a setting
  - higan/md, icarus: support all three combinations of SRAM (8-bit low,
    8-bit high, 16-bit)
  - processor/arm7tdmi: fix bug when changing to THUMB mode via MSR
    [MerryMage]
  - tomoko: redesigned crash detector to only occur once for all three
    ruby drivers
      - this will reduce disk thrashing since the configuration file
        only needs to be written out one extra time
      - technically, it's twice ... but we should've always been writing
        one out on first run in case it crashes then
  - tomoko: defaulted back to the safest ruby drivers, given the optimal
    drivers have some stability concerns

¹: minor errata: spotted a typo saying `synchronize(cpu)` when the CPU
is stopped, instead of `synchronize(ppu)`. This will be fixed in the v104
official 7zip archives.

I'm kind of rushing here but, it's really good timing for me to push out
a new official release. The blocking issues are resolved or close to it,
and we need lots of testing of the new major changes.

I'm going to consider this a semi-stable testing release and leave links
to v103 just in case.
2017-08-12 20:53:13 +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 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 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