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.
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.
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.
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.
byuu says:
Changelog:
- SMS: background VDP clips partial tiles on the left (math may not be
right ... it's hard to reason about)
- SMS: fix background VDP scroll locks
- SMS: fix VDP sprite coordinates
- SMS: paint black after the end of the visible display
- todo: shouldn't be a brute force at the end of the main VDP
loop, should happen in each rendering unit
- higan: removed emulator/debugger.hpp
- higan: removed privileged: access specifier
- SFC: removed debugger hooks
- todo: remove sfc/debugger.hpp
- Z80: fixed disassembly of (fd,dd) cb (displacement) (opcode)
instructions
- Z80: fix to prevent interrupts from firing between ix/iy prefixes
and opcodes
- todo: this is a rather hacky fix that could, if exploited, crash
the stack frame
- Z80: fix BIT flags
- Z80: fix ADD hl,reg flags
- Z80: fix CPD, CPI flags
- Z80: fix IND, INI flags
- Z80: fix INDR, INIT loop flag check
- Z80: fix OUTD, OUTI flags
- Z80: fix OTDR, OTIR loop flag check
byuu says:
Changelog:
- SMS: emulated the generic Sega memory mapper (none of the more
limited forms of it yet)
- (missing ROM shift, ROM write enable emulation -- no commercial
games use either, though)
- SMS: bus I/O returns 0xff instead of 0x00 so games don't think every
key is being pressed at once
- (this is a hack until I implement proper controller pad reading)
- SMS: very limited protection against reading/writing past the end of
ROM/RAM (todo: should mirror)
- SMS: VDP background HSCROLL subtracts, rather than adds, to the
offset (unlike VSCROLL)
- SMS: VDP VSCROLL is 9-bit, modulates voffset+vscroll to 224 in
192-line mode (32x28 tilemap)
- SMS: VDP tiledata for backgrounds and sprites use `7-(x&7)` rather
than `(x&7)`
- SMS: fix output color to be 6-bit rather than 5-bit
- SMS: left clip uses register `#7`, not palette color `#7`
- (todo: do we want `color[reg7]` or `color[16 + reg7]`?)
- SMS: refined handling of 0xcb, 0xed prefixes in the Z80 core and its
disassembler
- SMS: emulated (0xfd, 0xdd) 0xcb opcodes 0x00-0x0f (still missing
0x10-0xff)
- SMS: fixed 0xcb 0b-----110 opcodes to use direct HL and never allow
(IX,IY)+d
- SMS: fixed major logic bug in (IX,IY)+d displacement
- (was using `read(x)` instead of `operand()` for the displacement
byte fetch before)
- icarus: fake there always being 32KiB of RAM in all SMS cartridges
for the time being
- (not sure how to detect this stuff yet; although I've read it's
not even really possible `>_>`)
TODO: remove processor/z80/dissassembler.cpp code block at line 396 (as it's unnecessary.)
Lots of commercial games are starting to show trashed graphical output now.
byuu says:
Changelog:
- Makefile: added $(windres), -lpthread to Windows port
- GBA: WAITCNT.prefetch is not writable (should fix Donkey Kong: King
of Swing) \[endrift\]
- SMS: fixed hcounter shift value \[hex\_usr\]
- SMS: emulated interrupts (reset button isn't hooked up anywhere, not
sure where to put it yet)
This WIP actually took a really long time because the documentation on
SMS interrupts was all over the place. I'm hoping I've emulated them
correctly, but I honestly have no idea. It's based off my best
understanding from four or five different sources. So it's probably
quite buggy.
However, a few interrupts fire in Sonic the Hedgehog, so that's
something to start with. Now I just have to hope I've gotten some games
far enough in that I can start seeing some data in the VDP VRAM. I need
that before I can start emulating graphics mode 4 to get some actual
screen output.
Or I can just say to hell with it and use a "Hello World" test ROM.
That'd probably be smarter.
byuu says:
Changelog:
- SMS: extended bus mapping of in/out ports: now decoding them fully
inside ms/bus
- SMS: moved Z80 disassembly code from processor/z80 to ms/cpu
(cosmetic)
- SMS: hooked up non-functional silent PSG sample generation, so I can
cap the framerate at 60fps
- SMS: hooked up the VDP main loop: 684 clocks/scanline, 262
scanlines/frame (no PAL support yet)
- SMS: emulated the VDP Vcounter and Hcounter polling ... hopefully
it's right, as it's very bizarre
- SMS: emulated VDP in/out ports (data read, data write, status read,
control write, register write)
- SMS: decoding and caching all VDP register flags (variable names
will probably change)
- nall: \#undef IN on Windows port (prevent compilation warning on
processor/z80)
Watching Sonic the Hedgehog, I can definitely see some VDP register
writes going through, which is a good sign.
Probably the big thing that's needed before I can get enough into the
VDP to start showing graphics is interrupt support. And interrupts are
never fun to figure out :/
What really sucks on this front is I'm flying blind on the Z80 CPU core.
Without a working VDP, I can't run any Z80 test ROMs to look for CPU
bugs. And the CPU is certainly too buggy still to run said test ROM
anyway. I can't find any SMS emulators with trace logging from reset.
Such logs vastly accelerate tracking down CPU logic bugs, so without
them, it's going to take a lot longer.
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.
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.
Tim Allen