You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
57 lines
2.1 KiB
NASM
57 lines
2.1 KiB
NASM
|
|
; echo example - takes input and then prints it back out
|
|
; This is for testing the InputConsole of the Simple Test Machine
|
|
; by Joey Pollack
|
|
|
|
; assemble with win2c64 (or lin2c64, or mac2c64) using the -R option
|
|
; win2c64 found here:
|
|
; https://www.aartbik.com/retro.php
|
|
|
|
; CONSTANTS
|
|
con_out .equ $1100 ; console output buffer address
|
|
con_in .equ $1200 ; console input buffer address
|
|
con_flags .equ $009A ; console flags address
|
|
prt_str_flag .equ $0002 ; print string flag
|
|
prmp_input_flag .equ $0004 ; prompt for input flag
|
|
|
|
; MAIN
|
|
main .org $0200 ; program load address for the Simple Test Machine
|
|
ldx #0
|
|
loop lda text,x
|
|
sta con_out,x
|
|
inx
|
|
cpx #12 ; length of text
|
|
bne loop
|
|
|
|
; null terminate the string
|
|
lda #0
|
|
sta con_out,x
|
|
|
|
; Print the prompt message
|
|
lda con_flags ; load the console flags
|
|
ora #prt_str_flag ; set the print string flag
|
|
sta con_flags ; store the modified flags
|
|
|
|
; Prompt the user for input
|
|
lda con_flags ; load the console flags
|
|
ora #prmp_input_flag ; set the prompt for input flag
|
|
sta con_flags ; store the flags back to memory - this should trigger reading input
|
|
|
|
; Echo the input back to the console
|
|
; iterate the input buffer and move each byte to the output buffer
|
|
ldx #0 ; initialize the offset counter
|
|
loop2 lda con_in,x ; load byte from the input buffer, offset by x register
|
|
sta con_out,x ; store byte into output buffer, offset by x register
|
|
inx ; increment the offset
|
|
cmp #0 ; check for the null byte
|
|
bne loop2 ; branch back to loop2 if we are not at the null byte yet
|
|
|
|
lda con_flags ; load the console flags
|
|
ora #prt_str_flag ; set the print string flag
|
|
sta con_flags ; store the modified flags
|
|
|
|
; End the program
|
|
rts ; 0x60
|
|
|
|
; MEMORY
|
|
text .byte "Enter Text: " |