; Utility commands

cmd_h:	call eat_whitespace
	call eat_hex_word
	jc .err

	mov bx, dx

	call eat_whitespace
	call eat_hex_word
	jc .err

	xchg bx, dx

	push dx
	add dx, bx
	call print_dx
	call space
	pop dx

	sub dx, bx
	call print_dx

	jmp crlf
.err:	mov di, eat_hex_word.emsg
	jmp parse_error

cmd_?:	mov si, .txt
	jmp putcs
.txt:	db "G       Go", 0x0A, 0x0D
	db "H w w   Add and subtract two values", 0x0A, 0x0D
	db "R[r]    Print register values", 0x0A, 0x0D
	db "T       Single-Step", 0x0A, 0x0D
	db 0