mirror of https://github.com/bsnes-emu/bsnes.git
f7ddbfc462
byuu says:
Changelog:
- 68K: fixed NEG/NEGX operand order
- 68K: fixed bug in disassembler that was breaking trace logging
- VDP: improved sprite rendering (still 100% broken)
- VDP: added horizontal/vertical scrolling (90% broken)
Forgot:
- 68K: fix extension word sign bit on indexed modes for disassembler
as well
- 68K: emulate STOP properly (use r.stop flag; clear on IRQs firing)
I'm really wearing out fast here. The Genesis documentation is somehow
even worse than Game Boy documentation, but this is a far more complex
system.
It's a massive time sink to sit here banging away at every possible
combination of how things could work, only to see no positive
improvements. Nothing I do seems to get sprites to do a goddamn thing.
squee says the sprite Y field is 10-bits, X field is 9-bits. genvdp says
they're both 10-bits. BlastEm treats them like they're both 10-bits,
then masks off the upper bit so it's effectively 9-bits anyway.
Nothing ever bothers to tell you whether the horizontal scroll values
are supposed to add or subtract from the current X position. Probably
the most basic detail you could imagine for explaining horizontal
scrolling and yet ... nope. Nothing.
I can't even begin to understand how the VDP FIFO functionality works,
or what the fuck is meant by "slots".
I'm completely at a loss as how how in the holy hell the 68K works with
8-bit accesses. I don't know whether I need byte/word handlers for every
device, or if I can just hook it right into the 68K core itself. This
one's probably the most major design detail. I need to know this before
I go and implement the PSG/YM2612/IO ports-\>gamepads/Z80/etc.
Trying to debug the 68K is murder because basically every game likes to
start with a 20,000,000-instruction reset phase of checksumming entire
games, and clearing out the memory as agonizingly slowly as humanly
possible. And like the ARM, there's too many registers so I'd need three
widescreen monitors to comfortably view the entire debugger output lines
onscreen.
I can't get any test ROMs to debug functionality outside of full games
because every **goddamned** test ROM coder thinks it's acceptable to tell
people to go fetch some toolchain from a link that died in the late '90s
and only works on MS-DOS 6.22 to build their fucking shit, because god
forbid you include a 32KiB assembled ROM image in your fucking archives.
... I may have to take a break for a while. We'll see.
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| .. | ||
| apu | ||
| cartridge | ||
| cpu | ||
| interface | ||
| psg | ||
| system | ||
| vdp | ||
| ym2612 | ||
| GNUmakefile | ||
| md.hpp | ||