Task

Write a procedure which accepts as arguments another procedure and a positive integer.

The latter procedure is executed a number of times equal to the accepted integer.




macro RepeatProc,addr,count ;VASM macro syntax
; input: 
; addr = the label of the routine you wish to call repeatedly
; count = how many times you want to DO the procedure. 1 = once, 2 = twice, 3 = three times, etc. Enter "0" for 256 times.
lda #<\addr
sta z_L ;a label for a zero-page memory address
lda #>\addr
sta z_H ;a label for the zero-page memory address immediately after z_L
lda \count
jsr doRepeatProc
endm
 
doRepeatProc:
sta z_C   ;another zero-page memory location
loop_RepeatProc:
jsr Trampoline_RepeatProc
dec z_C
lda z_C
bne loop_RepeatProc
rts
 
Trampoline_RepeatProc:
db $6c,z_L,$00 
;when executed, becomes an indirect JMP to the address stored at z_L and z_H. Some assemblers will let you type
;JMP (z_L) and it will automatically replace it with the above during the assembly process.
;This causes an indirect JMP to the routine. Its RTS will return execution to just after the "JSR Trampoline_RepeatProc" 
;and flow into the loop overhead.