; count to 20 and log (using registers)
mov xc, 0b0000000000000000000000000 ; so many zeroes!
mov xa, 0x01

reg_loop:
	add xc, xa
	cmp xc, 20
	jlt reg_loop

log xc

; now use pointers!
mov xc, 0x00
mov xa, 0x01
mov *xc, 0
mov *xa, 1

ptr_loop:
	add *xc, *xa
	cmp *xc, 20
	jlt ptr_loop

log *xc