The-Homebrew-Cloud/Genesis-Plus-GX
2
0
Fork 0
mirror of https://github.com/ekeeke/Genesis-Plus-GX.git synced 2024-12-25 18:51:49 +01:00
Code Issues Packages Projects Releases Wiki Activity

[Core/MD] added emulation of 68k delay during Z80 acccess to 68k bus (fixes graphical glitch on Rick Dangerous II title screen introduced after adding emulation of 68k bus refresh delays)

Browse Source
This commit is contained in:
ekeeke 2024-05-01 18:44:46 +02:00
parent 0c45a8a8ab
commit f9f16d7a55
5 changed files with 9 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
HISTORY.txt
View File

@ -76,7 +76,8 @@ Genesis Plus GX 1.7.5 (xx/xx/xxxx) (Eke-Eke)
* added support for Everdrive extended SSF mapper * added support for Everdrive extended SSF mapper
* added support for MegaSD CD hardware overlay (MD+ hacks) and extended SSF2 / ROM write mappers * added support for MegaSD CD hardware overlay (MD+ hacks) and extended SSF2 / ROM write mappers
* added emulation of Z80 halt when accessing 68k bus during DMA from 68k bus * added emulation of Z80 halt when accessing 68k bus during DMA from 68k bus
* added basic emulation of 68k bus access refresh delays (fixes Super Airwolf graphical glitch during intro & some Krikzz's mcd-verificator timing tests) * added emulation of 68k delay during Z80 acccess to 68k bus
* added (basic) emulation of 68k bus refresh delays (fixes Super Airwolf graphical glitch during intro & some Krikzz's mcd-verificator timing tests)
* added (very basic) emulation of Flashkit MD hardware * added (very basic) emulation of Flashkit MD hardware
* added emulation of Micro Machines USA on-board TMSS bypass logic hardware * added emulation of Micro Machines USA on-board TMSS bypass logic hardware
* added SRAM support for games larger than 8MB * added SRAM support for games larger than 8MB

BIN
builds/genesis_plus_gx_libretro.dll
View File

Binary file not shown.

BIN
builds/genplus_cube.dol
View File

Binary file not shown.
Side by Side Swipe Overlay

Before

Width:  |  Height:  |  Size: 3.8 MiB

After

Width:  |  Height:  |  Size: 3.8 MiB

BIN
builds/genplus_wii.dol
View File

Binary file not shown.
Side by Side Swipe Overlay

Before

Width:  |  Height:  |  Size: 4.0 MiB

After

Width:  |  Height:  |  Size: 4.0 MiB

9
core/memz80.c
View File

@ -108,8 +108,13 @@ static void z80_request_68k_bus_access(void)
} }
} }
/* average Z80 wait-states when accessing 68k area */ /* approximate 68k wait-states during Z80 access to 68k bus (cf https://docs.google.com/document/d/1ST9GbFfPnIjLT5loytFCm3pB0kWQ1Oe34DCBBV8saY8) */
Z80.cycles += 3 * 15; /* value is adjusted to get ride of graphical glitches in Rick Dangerous 2 title screen when bus refresh delays are also emulated and still get */
/* "M68K DELAY ON Z80 ROM READ" test "passed" in Ti_'s test ROM (misc_test.bin), although the measured delay value is still slightly too high. */
m68k.cycles += ((Z80.cycles % 7) + 68);
/* average Z80 wait-states when accessing 68k bus (cf https://docs.google.com/document/d/1ST9GbFfPnIjLT5loytFCm3pB0kWQ1Oe34DCBBV8saY8) */
Z80.cycles += (3 * 15);
} }
unsigned char z80_memory_r(unsigned int address) unsigned char z80_memory_r(unsigned int address)