RaySollium99/picodrive
1
0
Fork 0
mirror of https://github.com/RaySollium99/picodrive.git synced 2025-09-05 15:27:46 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

md, implement z80 cycle stealing when accessing 68k bus

Browse source 
this fixes sound issues in Overdrive 2
This commit is contained in:
kub 2023-04-05 20:02:47 +02:00
parent d515a352b3
commit 134092feb7
3 changed files with 37 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

4
pico/pico_int.h
View file

@ -204,7 +204,8 @@ extern struct DrZ80 drZ80;
#define z80_cyclesDone() \
(Pico.t.z80c_aim - z80_cyclesLeft)
#define cycles_68k_to_z80(x) ((x) * 3822 >> 13)
// one line has 488 68K cycles and 228 Z80 cycles, 228/488*8192=3827
#define cycles_68k_to_z80(x) ((x) * 3857 >> 13)
// ----------------------- SH2 CPU -----------------------
@ -447,6 +448,7 @@ struct PicoTiming
unsigned int z80c_aim;
unsigned int z80c_line_start;
int z80_scanline;
int z80_buscycles;
int timer_a_next_oflow, timer_a_step; // in z80 cycles
int timer_b_next_oflow, timer_b_step;