doHandleGameTimer.asm

GetTrigger
BEQ +doTimer
JMP +skipTimer

+doTimer
;; Cycles the HUD element to update each timer cycle
;; NOTE: the "number" type HUD elements must all be consecutive
;; #$01, #$02, #$03 in this case, adjust for yours
LDA whichHudElement
CMP #$04 ;;; CHANGEME to 1 past the last element to update
BNE +yesUpdateHud
    LDA #$01 ;;; CHANGEME to the 1st element to update
    STA whichHudElement
    JMP +timerStart
+yesUpdateHud
UpdateHudElement whichHudElement
INC whichHudElement

+timerStart

+skipTimer