mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-01 01:06:33 +00:00
32 lines
492 B
ArmAsm
32 lines
492 B
ArmAsm
; HARDWARE LOCATIONS
|
|
|
|
KEYPRESS = $C000
|
|
KEYRESET = $C010
|
|
KEYSTROBE = $C010
|
|
|
|
; on original Apple II/II+
|
|
; read KEYPRESS
|
|
; if bit 7 set, means key was pressed, value in lower 7 bits
|
|
; access KEYSTROBE to clear value and allow another keypress to happen
|
|
; on Apple IIe
|
|
; can read KEYSTROBE. bit 7 is "any key is down"
|
|
|
|
|
|
; test keyboard
|
|
|
|
keyboard:
|
|
|
|
ldy #0
|
|
|
|
keyboard_loop:
|
|
lda KEYPRESS
|
|
bpl keyboard_loop
|
|
|
|
ora #$80
|
|
sta $400,Y
|
|
iny
|
|
bit KEYRESET
|
|
|
|
jmp keyboard_loop
|
|
|