RaySollium99/picodrive
1
0
Fork 0
mirror of https://github.com/RaySollium99/picodrive.git synced 2025-09-06 15:48:05 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

tried to adjust timers using formulae

Browse source 
git-svn-id: file:///home/notaz/opt/svn/PicoDrive@497 be3aeb3a-fb24-0410-a615-afba39da0efa
This commit is contained in:
notaz 2008-06-26 19:32:34 +00:00
parent e4fb433cd6
commit 45a1ef7153
3 changed files with 18 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

4
Pico/Memory.c
View file

@ -798,7 +798,7 @@ int ym2612_write_local(u32 a, u32 d, int is_from_z80)
ym2612.OPN.ST.TA = TAnew;
//ym2612.OPN.ST.TAC = (1024-TAnew)*18;
//ym2612.OPN.ST.TAT = 0;
timer_a_step = timer_a_offset = 16466 * (1024 - TAnew);
timer_a_step = timer_a_offset = TIMER_A_TICK_ZCYCLES * (1024 - TAnew);
if (ym2612.OPN.ST.mode & 1) {
int cycles = is_from_z80 ? z80_cyclesDone() : cycles_68k_to_z80(SekCyclesDone());
timer_a_next_oflow = (cycles << 8) + timer_a_step;
@ -813,7 +813,7 @@ int ym2612_write_local(u32 a, u32 d, int is_from_z80)
ym2612.OPN.ST.TB = d;
//ym2612.OPN.ST.TBC = (256-d) * 288;
//ym2612.OPN.ST.TBT = 0;
timer_b_step = timer_b_offset = 262800 * (256 - d); // 262881
timer_b_step = timer_b_offset = TIMER_B_TICK_ZCYCLES * (256 - d); // 262800
if (ym2612.OPN.ST.mode & 2) {
int cycles = is_from_z80 ? z80_cyclesDone() : cycles_68k_to_z80(SekCyclesDone());
timer_b_next_oflow = (cycles << 8) + timer_b_step;

8
Pico/PicoInt.h
View file

@ -480,6 +480,10 @@ void ym2612_pack_state(void);
void ym2612_unpack_state(void);
#define TIMER_NO_OFLOW 0x70000000
// tA = 72 * (1024 - NA) / M
#define TIMER_A_TICK_ZCYCLES 17203
// tB = 1152 * (256 - NA) / M
#define TIMER_B_TICK_ZCYCLES 262800 // 275251 broken, see Dai Makaimura
#define timers_cycle() \
if (timer_a_next_oflow > 0 && timer_a_next_oflow < TIMER_NO_OFLOW) \
@ -490,8 +494,8 @@ void ym2612_unpack_state(void);
#define timers_reset() \
timer_a_next_oflow = timer_b_next_oflow = TIMER_NO_OFLOW; \
timer_a_step = timer_a_offset = 16495 * 1024; \
timer_b_step = timer_b_offset = 263912 * 256;
timer_a_step = timer_a_offset = TIMER_A_TICK_ZCYCLES * 1024; \
timer_b_step = timer_b_offset = TIMER_B_TICK_ZCYCLES * 256;
// VideoPort.c