mirror of
https://github.com/cc65/cc65.git
synced 2024-12-23 19:29:37 +00:00
e12444824f
Made k_blncur a condes IRQ routine and moved it to cgetc.s. Added mouse and joystick routines. git-svn-id: svn://svn.cc65.org/cc65/trunk@951 b7a2c559-68d2-44c3-8de9-860c34a00d81
63 lines
1.1 KiB
ArmAsm
63 lines
1.1 KiB
ArmAsm
;
|
|
; Ullrich von Bassewitz, 23.09.1998
|
|
;
|
|
; unsigned readjoy (unsigned char joy);
|
|
;
|
|
|
|
.export _readjoy
|
|
.import sys_bank, restore_bank
|
|
.importzp cia2, tmp1
|
|
|
|
.include "io.inc"
|
|
|
|
; ------------------------------------------------------------------------
|
|
; unsigned __fastcall__ readjoy (unsigned char joy);
|
|
|
|
|
|
.proc _readjoy
|
|
|
|
jsr sys_bank ; Switch to the system bank
|
|
tax ; Save joystick number
|
|
|
|
; Get the direction bits
|
|
|
|
ldy #CIA_PRB
|
|
lda (cia2),y ; Read joystick inputs
|
|
sta tmp1
|
|
|
|
; Get the fire bits
|
|
|
|
ldy #CIA_PRA
|
|
lda (cia2),y
|
|
|
|
; Make the result value
|
|
|
|
cpx #$00 ; Joystick 0?
|
|
bne @L1 ; Jump if no
|
|
|
|
; Joystick 1, fire is in bit 6, direction in bit 0-3
|
|
|
|
asl a
|
|
jmp @L2
|
|
|
|
; Joystick 2, fire is in bit 7, direction in bit 5-7
|
|
|
|
@L1: ldy #$00 ; High byte of return value
|
|
lsr tmp1
|
|
lsr tmp1
|
|
lsr tmp1
|
|
lsr tmp1
|
|
|
|
; Mask the relavant bits, get the fire bit
|
|
|
|
@L2: asl a ; Fire bit into carry
|
|
lda tmp1
|
|
and #$0F
|
|
bcc @L3
|
|
ora #$10
|
|
@L3: eor #$1F ; All bits are inverted
|
|
jmp restore_bank
|
|
|
|
.endproc
|
|
|