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Bugs:Al Unser Jr. Turbo Racing

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This page details bugs of Al Unser Jr. Turbo Racing.

Timer Bug

In time delayed scenes, a timer is used stored at location 6460 in the game's SRAM. Due to a branch instruction oversight, it mistakenly cuts off 256 frames too soon, thus cutting off the full music track for said scenes.

8997    dec $6460	;decrement timer (lower byte)
899A    bne $8972	;if it's !=0, branch to beginning of subroutine
899C    lda $6461	;if not, load higher byte
899F    beq $89A6	;if that equals 0, branch to 89A6
89A1    dec $6461	;decrement timer (higher byte)
89A4    bne $8972	;then branch to beginning of subroutine, which will fail if the higher byte is decremented from 1 to 0, which will skip 256 frames. Replacing the instruction with a BPL will fix this.
89A6    lda #$00	;load 0
89A8    sta $6462	;store in $6462
;end
89AB    rts		;and return
Original Fixed


The following Game Genie codes will fix the bug and revert the timer to its intended behavior.

Japan: AOXAOLEI
US/Europe: AOXAKPEI