emailler/drivers/a2print.s

.export print_a
.export print_a_inverse
.export print_cr
.export cls
.export beep
.exportzp screen_current_row
.exportzp screen_current_col


.code

screen_current_col = $24        ; CH - Horizontal cursor-position (0-39)
screen_current_row = $25        ; CV - Vertical cursor-position (0-23)

; use Apple 2 monitor ROM function to display 1 char
; inputs: A should be set to ASCII char to display
; outputs: none
print_a:
  ora #$80                      ; turn ASCII into Apple 2 screen codes
  cmp #$8A                      ; is it a line feed?
  bne @not_line_feed
; jmp print_cr
  pha
  lda #$0
  sta screen_current_col
  pla
@not_line_feed:
  jmp $fded

; use Apple 2 monitor ROM function to move to new line
; inputs: none
; outputs: none
print_cr:
  jmp $fd8e

; use Apple 2 monitor ROM function to move to clear the screen
; inputs: none
; outputs: none
cls:
  jmp $fc58

; use Apple 2 monitor ROM function to move to make a 'beep' noise
; inputs: none
; outputs: none
beep:
  jmp $fbdd

print_a_inverse:
  and  #$7F                     ; turn off top bits
  jsr $fded



; -- LICENSE FOR a2print.s --
; The contents of this file are subject to the Mozilla Public License
; Version 1.1 (the "License"); you may not use this file except in
; compliance with the License. You may obtain a copy of the License at
; http://www.mozilla.org/MPL/
;
; Software distributed under the License is distributed on an "AS IS"
; basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
; License for the specific language governing rights and limitations
; under the License.
;
; The Original Code is ip65.
;
; The Initial Developer of the Original Code is Jonno Downes,
; jonno@jamtronix.com.
; Portions created by the Initial Developer are Copyright (C) 2009
; Jonno Downes. All Rights Reserved.
; -- LICENSE END --