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: emulated the remaining 240 instructions in the (0xfd, 0xdd)
0xcb (displacement) (opcode) set
- 1/8th of these were "legal" instructions, and apparently games
use them a lot
- SMS: emulated the standard gamepad controllers
- reset button not emulated yet
The reset button is tricky. In every other case, reset is a hardware
thing that instantly reboots the entire machine.
But on the SMS, it's more like a gamepad button that's attached to the
front of the device. When you press it, it fires off a reset vector
interrupt and the gamepad polling routine lets you query the status of
the button.
Just having a reset option in the "Master System" hardware menu is not
sufficient to fully emulate the behavior. Even more annoying is that the
Game Gear doesn't have such a button, yet the core information structs
aren't flexible enough for the Master System to have it, and the Game
Gear to not have it, in the main menu. But that doesn't matter anyway,
since it won't work having it in the menu for the Master System.
So as a result, I'm going to have to have a new "input device" called
"Hardware" that has the "Reset" button listed under there. And for the
sake of consistency, I'm not sure if we should treat the other systems
the same way or not :/
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