Bubble Sort in ASM

	ORG	C0		; Place following code starting at [C0] (VDU)
	DB	"12345"		; Place list to be sorted in memory
	ORG	0		; Place following code starting at [00]
START:
	CLO			; Close unwanted windows
	MOV	AL,0		; Swap register
	MOV	BL,0		; Swap register
	MOV	CL,C0		; Display pointer
	MOV	DL,0		; Swap counter
	MOV	AL,20		; Move " " to AL
	MOV	[C5],AL		; Move AL to RAM [C5] (hardcoded for display popup)
	MOV	AL,0		; Reset AL for program start
MAIN:
	CMP	DL,5		; Check for sorting completion (swap counter starts at 0,
				; decrements at each comparison with a swap, increments at
				; each comparison without a swap, value of 5 marks fully sorted with no false positives)
	JZ	BYE		; Exit if list is sorted
	CMP	CL,C4		; Is the display pointer at the end of the list?
	JZ	RESET		; If yes, jump to reset label
	MOV	AL,[CL]		; Move value at display pointer to AL
	INC 	CL		; Increment display pointer to get next value
	MOV	BL,[CL]		; Move value at display pointer to BL
	CMP 	AL,BL		; Is AL greater than BL?
	JNS	SWAP		; If yes, jump to swap label
	CMP	BL,AL		; Is BL greater than AL?
	JNS	CHECK		; If yes, jump to check label
CHECK:
	INC	DL		; Increment swap counter
	JMP 	MAIN		; Jump back to main loop
SWAP:
	DEC	DL		; Decrement swap counter
	PUSH	AL		; Push value 1 to stack from AL
	PUSH	BL		; Push value 2 to stack from BL
	POP	AL		; Pop value 2 from stack to AL
	POP	BL		; Pop value 1 from stack to BL
	DEC	CL		; Decrement display pointer
	MOV	[CL],AL		; Move AL to [CL]
	INC	CL		; Increment display pointer
	MOV	[CL],BL		; Move BL to [CL]
	JMP 	MAIN		; Jump back to main loop
RESET:
	MOV	CL,C0		; Reset display pointer to C0
	JMP	MAIN		; Jump back to main loop
BYE:
	END			; End program