byuu says:
Changelog:
- gb/mbc6: mapper is now functional, but Net de Get has some text
corruption¹
- gb/mbc7: mapper is now functional²
- gb/cpu: HDMA syncs other components after each byte transfer now
- gb/ppu: LY,LX forced to zero when LCDC.d7 is lowered (eg disabled),
not when it's raised (eg enabled)
- gb/ppu: the LCD does not run at all when LCDC.d7 is clear³
- fixes graphical corruption between scene transitions in Legend
of Zelda - Oracle of Ages
- thanks to Cydrak, Shonumi, gekkio for their input on the cause
of this issue
- md/controller: renamed "Gamepad" to "Control Pad" per official
terminology
- md/controller: added "Fighting Pad" (6-button controller) emulation
[hex\_usr]
- processor/m68k: fixed TAS to set data.d7 when
EA.mode==DataRegisterDirect; fixes Asterix
- hiro/windows: removed carriage returns from mouse.cpp and
desktop.cpp
- ruby/audio/alsa: added device driver selection [SuperMikeMan]
- ruby/audio/ao: set format.matrix=nullptr to prevent a crash on some
systems [SuperMikeMan]
- ruby/video/cgl: rename term() to terminate() to fix a crash on macOS
[Sintendo]
¹: The observation that this mapper split $4000-7fff into two banks
came from MAME's implementation. But their implementation was quite
broken and incomplete, so I didn't actually use any of it. The
observation that this mapper split $a000-bfff into two banks came from
Tauwasser, and I did directly use that information, plus the knowledge
that $0400/$0800 are the RAM bank select registers.
The text corruption is due to a race condition with timing. The game is
transferring font letters via HDMA, but the game code ends up setting
the bank# with the font a bit too late after the HDMA has already
occurred. I'm not sure how to fix this ... as a whole, I assumed my Game
Boy timing was pretty good, but apparently it's not that good.
²: The entire design of this mapper comes from endrift's notes.
endrift gets full credit for higan being able to emulate this mapper.
Note that the accelerometer implementation is still not tested, and
probably won't work right until I tweak the sensitivity a lot.
³: So the fun part of this is ... it breaks the strict 60fps rate of
the Game Boy. This was always inevitable: certain timing conditions can
stretch frames, too. But this is pretty much an absolute deal breaker
for something like Vsync timing. This pretty much requires adaptive sync
to run well without audio stuttering during the transition.
There's currently one very important detail missing: when the LCD is
turned off, presumably the image on the screen fades to white. I do not
know how long this process takes, or how to really go about emulating
it. Right now as an incomplete patch, I'm simply leaving the last
displayed image on the screen until the LCD is turned on again. But I
will have to output white, as well as add code to break out of the
emulation loop periodically when the LCD is left off eg indefinitely, or
bad things would happen. I'll work something out and then implement.
Another detail is I'm not sure how long it takes for the LCD to start
rendering again once enabled. Right now, it's immediate. I've heard it's
as long as 1/60th of a second, but that really seems incredibly
excessive? I'd like to know at least a reasonably well-supported
estimate before I implement that.
byuu says:
Changelog:
- fc/controller: added ControllerPort class; removed Peripherals class
- md/controller/gamepad: removed X,Y,Z buttons since this isn't a
6-button controller
- ms/controller: added ControllerPort class (not used in Game Gear
mode); removed Peripherals class
- pce/controller: added ControllerPort class; removed Peripherals
class
- processor/spc700: idle(address) is part of SMP class again, contains
flag to detect mov (x)+ edge case
- sfc/controller/super-scope,justifier: use CPU frequency instead of
hard-coding NTSC frequency
- sfc/cpu: move 4x8-bit SMP ports to SMP class
- sfc/smp: move APU RAM to DSP class
- sfc/smp: improved emulation of TEST registers bits 4-7 [information
from nocash]
- d4,d5 is RAM wait states (1,2,5,10)
- d6,d7 is ROM/IO wait states (1,2,5,10)
- sfc/smp: code cleanup to new style (order from lowest to highest
bits; use .bit(s) functions)
- sfc/smp: $00f8,$00f9 are P4/P5 auxiliary ports; named the registers
better
byuu says:
Changelog:
- fc/apu: $4003,$4007 writes initialize duty counter to 0 instead of 7
- fc/apu: corrected duty table entries for use with decrementing duty
counter
- processor/spc700: emulated the behavior of cycle 3 of (x)+
instructions to not read I/O registers
- specifically, this prevents reads from $fd-ff from resetting the
timers, as observed on real hardware
- sfc/controller: added ControllerPort class to match Mega Drive
design
- sfc/expansion: added ExpansionPort class to match Mega Drive design
- sfc/system: removed Peripherals class
- sfc/system: changed `colorburst()` to `cpuFrequency()`; added
`apuFrequency()`
- sfc: replaced calls to `system.region == System::Region::*` with
`Region::*()`
- sfc/expansion: remove thread from scheduler when device is destroyed
- sfc/smp: `{read,write}Port` now use a separate 4x8-bit buffer instead
of underlying APU RAM [hex\_usr]
byuu says:
Changelog:
- fc/apu: improved phase duty cycle emulation (mode 3 is 25% phase
inverted; counter decrements)
- md/apu: power/reset do not cancel 68K bus requests
- md/apu: 68K is not granted bus access on Z80 power/reset
- md/controller: replaced System::Peripherals with ControllerPort
concept
- md/controller: CTRL port is now read-write, maintains value across
controller changes (and soon, soft resets)
- md/psg: PSG sampling rate unintentionally modified¹
- processor/spc700: improve cycle timing of (indirect),y instructions
[Overload]
- processor/spc700: idle() cycles actually read from the program
counter; much like the 6502 [Overload]
- some of the idle() cycles should read from other addresses; this
still needs to be supported
- processor/spc700: various cleanups to instruction function naming
- processor/z80: prefix state (HL→IX,IY override) can now be
serialized
- icarus: fix install rule for certain platforms (it wasn't buggy on
FreeBSD, but was on Linux?)
¹: the clock speed of the PSG is oscillator/15. But I was setting the
sampling rate to oscillator/15/16, which was around 223KHz. I am not
sure whether the PSG should be outputting at 3MHz or 223KHz. Amazingly
... I don't really hear a difference either way `o_O` I didn't actually
mean to make this change; I just noticed it after comparing the diff
between r01 and r02. If this turns out to be wrong, set
stream = Emulator::audio.createStream(1, frequency() / 16.0);
in md/psg.cpp to revert this change.
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:
- 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:
- 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:
- 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.
Tim Allen