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Fixed 6522.T2 interrupt for Lancaster (#765)

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This commit is contained in:
tomcw 2020-02-29 18:48:46 +00:00
parent 2f9ba13216
commit ef4ee4ed16
1 changed files with 4 additions and 20 deletions
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24
source/Mockingboard.cpp
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@ -446,7 +446,7 @@ static void SY6522_Write(BYTE nDevice, BYTE nReg, BYTE nValue)
// Clear Timer2 Interrupt Flag.
UpdateIFR(pMB, IxR_TIMER2);
pMB->sy6522.TIMER2_LATCH.h = nValue;
pMB->sy6522.TIMER2_LATCH.h = nValue; // NB. Real 6522 doesn't have TIMER2_LATCH.h
pMB->sy6522.TIMER2_COUNTER.w = pMB->sy6522.TIMER2_LATCH.w;
StartTimer2(pMB);
@ -488,11 +488,9 @@ static void SY6522_Write(BYTE nDevice, BYTE nReg, BYTE nValue)
UpdateIFR(pMB, 0);
// Check if a timer interrupt has been enabled (regardless of if there's an active timer or not): GH#567
// . NB. Not Timer2 - only TIMER2H can make it active (GH#765)
if (pMB->sy6522.IER & IxR_TIMER1)
StartTimer1(pMB);
if (pMB->sy6522.IER & IxR_TIMER2)
StartTimer2(pMB);
}
break;
case 0x0f: // ORA_NO_HS
@ -1934,22 +1932,8 @@ bool MB_UpdateCycles(ULONG uExecutedCycles)
{
UpdateIFR(pMB, 0, IxR_TIMER2);
if((pMB->sy6522.ACR & RUNMODE) == RM_ONESHOT)
{
StopTimer2(pMB);
}
else
{
pMB->sy6522.TIMER2_COUNTER.w += pMB->sy6522.TIMER2_LATCH.w;
if (pMB->sy6522.TIMER2_COUNTER.w > pMB->sy6522.TIMER2_LATCH.w)
{
if (pMB->sy6522.TIMER2_LATCH.w)
pMB->sy6522.TIMER2_COUNTER.w %= pMB->sy6522.TIMER2_LATCH.w;
else
pMB->sy6522.TIMER2_COUNTER.w = 0;
}
StartTimer2(pMB);
}
// TIMER2 only runs in one-shot mode
StopTimer2(pMB);
}
}