added helper marks for head align tool, use CIA for stable timing

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FeralChild64 committed 2020-06-03 16:43:21 +02:00
1 parent db9d6e7b60
commit 0b13ce175e
4 files changed
+129 -40

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@@ -138,26 +138,26 @@ IOINIT:
// Checked using VICE that original ROM initializes timers this way
ldx #$08
stx CIA1_CRB // $DC0F
stx CIA2_CRA // $DD0E
stx CIA2_CRB // $DD0F
stx CIA1_CRB // $DC0F
stx CIA2_CRA // $DD0E
stx CIA2_CRB // $DD0F
// Set VIC-II bank - at least the 'Operacja Proboszcz' game needs this within IOINIT
// Checked on original ROMs, that it sets bit #2 (RS-232 output) high
ldx #%00000111 // XXX adapt this to IEC idle state, JMP at the end won't be needed
stx CIA2_PRA // $DD00
stx CIA2_PRA // $DD00
// Put something sane in the IRQ timer
jsr setup_irq_timer
// Enable timer A to run continuously (http://codebase64.org/doku.php?id=base:timerinterrupts)
ldx #$11
stx CIA1_CRA // $DC0E
stx CIA1_CRA // $DC0E
// Enable timer interrupt
ldx #$81
stx CIA1_ICR // $DC0D
stx CIA1_ICR // $DC0D
#if CONFIG_IEC