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improved Z80 interrupt timing accuracy

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This commit is contained in:
ekeeke31 2010-08-19 13:22:12 +00:00
parent 9f4806a37d
commit b82c22c2e9
1 changed files with 9 additions and 5 deletions
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14
source/system.c
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@ -408,9 +408,14 @@ void system_frame (int do_skip)
if (!do_skip && ((line < end) || (line >= start)))
render_line(line);
/* clear pending Z80 interrupt */
if (zirq)
{
/* Z80 interrupt is asserted during one exact line */
m68k_run(mcycles_vdp + 788);
if (zstate == 1) z80_run(mcycles_vdp + 788);
else mcycles_z80 = mcycles_vdp + 788;
/* clear Z80 interrupt */
z80_set_irq_line(0, CLEAR_LINE);
zirq = 0;
}
@ -457,10 +462,6 @@ void system_frame (int do_skip)
/* update inputs (doing this here fix Warriors of Eternal Sun) */
osd_input_Update();
/* Z80 interrupt is 16ms period (one frame) and 64us length (one scanline) */
z80_set_irq_line(0, ASSERT_LINE);
zirq = 1;
/* delay between VINT flag & V Interrupt (Ex-Mutants, Tyrant) */
m68k_run(mcycles_vdp + 588);
status |= 0x80;
@ -474,6 +475,9 @@ void system_frame (int do_skip)
vint_pending = 0x20;
if (reg[1] & 0x20)
irq_status = (irq_status & ~0x40) | 0x36;
/* Z80 interrupt */
z80_set_irq_line(0, ASSERT_LINE);
}
else
{