emailler/client/drivers/a2print.s

56 lines
1.0 KiB
ArmAsm

.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