#define echo    $FFEF
#define kbd_data $D010
#define kbd_cr $D011
#define serial_ready $C000
#define serial_read  $C080
#define serial_write $C081

* = $C200
.dsb (*-end_of_apple1serial), 0

; teletype on apple-1
* = $C200
teletype_apple1 = $C200
  lda serial_read
wait
  lda serial_ready
  beq wait
  lda serial_read
  jsr echo
  jmp wait
end_of_teletype_apple1

; AD 80 C0 AD 00 C0 F0 FB
; AD 80 C0 20 EF FF 4C 03
; 00

; teletype on remote
* = $C300
.dsb (*-end_of_teletype_apple1), 0

* = $C300
teletype_remote = $C300
  lda #$FF
  sta serial_write
get_key
  lda kbd_cr
  bpl get_key
  lda kbd_data
  sec
  sbc #$A0
  sta serial_write
  jmp get_key
end_of_teletype_remote

; A9 FF 8D 81 C0 AD 11 D0
; 10 FB AD 10 D0 38 E9 A0
; 8D 81 C0 4C 85 02

; 0-255 repeating counter over TXD
* = $C400
.dsb (*-end_of_teletype_remote), 0

* = $C400
counter_remote = $C400
  ldy #$00
  sta serial_write
check_ready
  lda serial_ready
  beq check_ready
  tya
  sta serial_write
  iny
  jmp check_ready

; A0 00 8D 81 C0 AD 00 C0
; F0 FB 98 8D 81 C0 C8 4C
; 85 02