"E97": example of cycle program

Type latin alphabet from "A" to "Z" on display screen.

The initial symbol "A" has code 65=41h. So we put it into R0 and call ROM subroutine, that outputs character. The next letter can be get after increment of R0. If the result exceeds 5Ah ("Z"), the cycle ends.

Address	Code	Operation	Comments
0000 0002	0E6D 0030	30 ==> SP	set SP for correct subroutine calls
0004 0006	01D0 0041	41 ==> R0 ("A")	first symbol code
0008 000A	9C0D 4088	call subroutine 4088	output to screen
000C	2210	R0 + 1 ==> R0	next symbol
000E 0010	04D0 005A	compare R0 with 5A ("Z")	code <= "Z"?
0012	6DF4	if <=0, then pc=pc+F4	repeat cycle (to 0008)
0014	0F00	halt	stop

Try and examine, how it works in "E97".