Flunky: Routine at 9AA9

9AA9: Graphic layout routine: (245) Decrease timer value, and if zero, reset and write random graphic index from list into next instruction

Decrease timer value (1st parameter). If now zero, then reset timer to value in 2nd parameter, then load one of the n (3rd parameter) following values chosen at random into the graphic index field of the next instruction.

Input
IX	Address of first parameter in current graphic layout data instruction

Output
B	Do-not-recalculate-display-buffer-address flag (00)
IX	Address of next graphic layout data instruction to process

9AA9

LD B,$00

Prepare to recalculate display buffer address.

9AAB

DEC (IX+$00)

Decrease timer value.

9AAE

JR NZ,$9AC0

If timer is not zero, then advance IX to start of next instruction and process.

9AB0

CALL $9ACF

Reset timer to maximum, advance IX to start of next instruction and set value here (graphic index) to random value from sequence of data following previous instruction.

9AB3

LD (IX+$00),E

9AB6

JP $989E

Read / process data at address in IX.