org &8000
PrintChar equ &BB5A   ;syscall - prints accumulator to Amstrad CPC's screen


main:

	ld hl,TestData0
	call PrintBinary_NoLeadingZeroes

	ld hl,TestData1
	call PrintBinary_NoLeadingZeroes

	ld hl,TestData2
	call PrintBinary_NoLeadingZeroes

	ret

TestData0:
	byte 5,255
TestData1:
	byte 5,0,255
TestData2:
	byte 9,0,0,0,255

temp:
    byte 0	
	;temp storage for the accumulator
	;	we can't use the stack to preserve A since that would also preserve the flags.


PrintBinary_NoLeadingZeroes:
;setup:
	ld bc,&8000            ;B is the revolving bit mask, C is the "have we seen a zero yet" flag


NextDigit:
	ld a,(hl)
	inc hl
	cp 255
	jp z,Terminated
	
	ld (temp),a
NextBit:
	ld a,(temp)
	and b
	jr z,PrintZero
	; else, print one
	ld a,'1'                ;&31
	call &BB5A
	set 0,b			;bit 0 of B is now 1, so we can print zeroes now.
	jr Predicate
	
PrintZero:
	ld a,b
	or a
	jr z,Predicate		;if we haven't seen a zero yet, don't print a zero.
	ld a,'0'		;&30
	call &BB5A
	
	
Predicate:
	rrc b				
	;rotate the mask right by one. If it sets the carry,
	;	it's back at the start, and we need to load the next byte.
	jr nc,NextBit
	
	jr NextDigit		;back to top
	
Terminated:
	ld a,13
	call &BB5A
	ld a,10
	jp &BB5A		;its ret will return for us.