;
; SUB: A = A - B
;
	LD A, 01110001B	; 71D (packed BCD)
	LD B, 01010100B	; 54D (packed BCD)
	OUT (00H), A	; Set LEDs in 00H with 1st operand
	LD C, 01H
	OUT (C), B	; Set LEDs in 01H B with 2nd operand

	SUB B		; B is substracted from A, and the result is written back to A
	OUT (02H), A	; Send result (expect 0001 1101 = 1DH) of A - B to 02H

;
; The A register is BCD corrected using the contents of the flags.
; See: http://z80-heaven.wikidot.com/instructions-set:daa
;
	DAA		; A register is BCD corrected using the contents of the Flags
	OUT (03H), A	; Set LEDs in 03H with content DAA result, expect 0001 0111 = 17D