mirror of
https://github.com/cc65/cc65.git
synced 2024-11-16 02:10:52 +00:00
837 lines
20 KiB
ArmAsm
837 lines
20 KiB
ArmAsm
;
|
|
; Mouse driver for ST & Amiga mouses and Atari trakball.
|
|
;
|
|
; Original access routines: 05/07/2000 Freddy Offenga
|
|
; Converted to driver: Christian Groessler, 2014-01-04
|
|
;
|
|
; Defines:
|
|
; AMIGA_MOUSE - builds Amiga mouse version
|
|
; TRAK_MOUSE - builds trakball version
|
|
; If none of these defines are active, the ST mouse version
|
|
; is being built.
|
|
;
|
|
|
|
;DEBUG = 1
|
|
|
|
DISABLE_TIMEOUT = 30 ; # of vertical blank interrupts after which, if
|
|
; no mouse motion occurred, the polling IRQ gets
|
|
; disabled.
|
|
; VBI frequency is 50Hz for PAL and 60Hz for NTSC
|
|
|
|
.include "zeropage.inc"
|
|
.include "mouse-kernel.inc"
|
|
.include "atari.inc"
|
|
|
|
.macpack generic
|
|
.macpack module
|
|
|
|
.if .not ( .defined (AMIGA_MOUSE) .or .defined (TRAK_MOUSE))
|
|
ST_MOUSE = 1
|
|
.endif
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table
|
|
|
|
.if .defined (ST_MOUSE)
|
|
|
|
.ifdef __ATARIXL__
|
|
module_header _atrxst_mou
|
|
.else
|
|
module_header _atrst_mou
|
|
.endif
|
|
|
|
.elseif .defined (AMIGA_MOUSE)
|
|
|
|
.ifdef __ATARIXL__
|
|
module_header _atrxami_mou
|
|
.else
|
|
module_header _atrami_mou
|
|
.endif
|
|
|
|
.elseif .defined (TRAK_MOUSE)
|
|
|
|
.ifdef __ATARIXL__
|
|
module_header _atrxtrk_mou
|
|
.else
|
|
module_header _atrtrk_mou
|
|
.endif
|
|
|
|
.endif
|
|
|
|
HEADER:
|
|
|
|
; Driver signature
|
|
|
|
.byte $6d, $6f, $75 ; "mou"
|
|
.byte MOUSE_API_VERSION ; Mouse driver API version number
|
|
|
|
; Library reference
|
|
|
|
libref: .addr $0000
|
|
|
|
; Jump table
|
|
|
|
.addr INSTALL
|
|
.addr UNINSTALL
|
|
.addr HIDE
|
|
.addr SHOW
|
|
.addr SETBOX
|
|
.addr GETBOX
|
|
.addr MOVE
|
|
.addr BUTTONS
|
|
.addr POS
|
|
.addr INFO
|
|
.addr IOCTL
|
|
.addr IRQ
|
|
|
|
; Mouse driver flags
|
|
|
|
.byte MOUSE_FLAG_LATE_IRQ
|
|
|
|
; Callback table, set by the kernel before INSTALL is called
|
|
|
|
CHIDE: jmp $0000 ; Hide the cursor
|
|
CSHOW: jmp $0000 ; Show the cursor
|
|
CPREP: jmp $0000 ; Prepare to move the cursor
|
|
CDRAW: jmp $0000 ; Draw the cursor
|
|
CMOVEX: jmp $0000 ; Move the cursor to X coord
|
|
CMOVEY: jmp $0000 ; Move the cursor to Y coord
|
|
|
|
|
|
;----------------------------------------------------------------------------
|
|
; Constants
|
|
|
|
SCREEN_HEIGHT = 191
|
|
SCREEN_WIDTH = 319
|
|
|
|
.enum JOY
|
|
UP = $01
|
|
DOWN = $02
|
|
LEFT = $04
|
|
RIGHT = $08
|
|
.endenum
|
|
|
|
;----------------------------------------------------------------------------
|
|
; Global variables. The bounding box values are sorted so that they can be
|
|
; written with the least effort in the SETBOX and GETBOX routines, so don't
|
|
; reorder them.
|
|
|
|
.bss
|
|
|
|
Vars:
|
|
YPos: .res 2 ; Current mouse position, Y
|
|
XPos: .res 2 ; Current mouse position, X
|
|
XMin: .res 2 ; X1 value of bounding box
|
|
YMin: .res 2 ; Y1 value of bounding box
|
|
XMax: .res 2 ; X2 value of bounding box
|
|
YMax: .res 2 ; Y2 value of bounding box
|
|
Buttons: .res 1 ; Button mask
|
|
OldButton: .res 1 ; previous buttons
|
|
|
|
XPosWrk: .res 2
|
|
YPosWrk: .res 2
|
|
|
|
irq_enabled: .res 1 ; flag indicating that the high frequency polling interrupt is enabled
|
|
old_porta_vbi: .res 1 ; previous PORTA value of the VBI interrupt (IRQ)
|
|
how_long: .res 1 ; counter for how many VBI interrupts the mouse hasn't been moved
|
|
in_irq: .res 1 ; flag indicating high-frequency polling interrupt is active
|
|
|
|
.if .defined (AMIGA_MOUSE) .or .defined (ST_MOUSE)
|
|
dumx: .res 1
|
|
dumy: .res 1
|
|
.endif
|
|
|
|
.ifdef TRAK_MOUSE
|
|
oldval: .res 1
|
|
.endif
|
|
|
|
.ifndef __ATARIXL__
|
|
OldT2: .res 2
|
|
.else
|
|
|
|
.data
|
|
set_VTIMR2_handler:
|
|
.byte $4C, 0, 0
|
|
.endif
|
|
|
|
.rodata
|
|
|
|
; Default values for some of the above variables
|
|
; (We use ".proc" because we want to define both a label and a scope.)
|
|
|
|
.proc DefVars
|
|
.word (SCREEN_HEIGHT+1)/2 ; YPos
|
|
.word (SCREEN_WIDTH+1)/2 ; XPos
|
|
.word 0 ; XMin
|
|
.word 0 ; YMin
|
|
.word SCREEN_WIDTH ; XMax
|
|
.word SCREEN_HEIGHT ; YMax
|
|
.byte 0 ; Buttons
|
|
.endproc
|
|
|
|
.ifdef ST_MOUSE
|
|
|
|
; ST mouse lookup table
|
|
|
|
STTab: .byte $FF,$01,$00,$01
|
|
.byte $00,$FF,$00,$01
|
|
.byte $01,$00,$FF,$00
|
|
.byte $01,$00,$01,$FF
|
|
|
|
.endif
|
|
|
|
.ifdef AMIGA_MOUSE
|
|
|
|
; Amiga mouse lookup table
|
|
|
|
AmiTab: .byte $FF,$01,$00,$FF
|
|
.byte $00,$FF,$FF,$01
|
|
.byte $01,$FF,$FF,$00
|
|
.byte $FF,$00,$01,$FF
|
|
|
|
.endif
|
|
|
|
.code
|
|
|
|
;----------------------------------------------------------------------------
|
|
; INSTALL routine. Is called after the driver is loaded into memory. If
|
|
; possible, check if the hardware is present.
|
|
; Must return an MOUSE_ERR_xx code in a/x.
|
|
|
|
INSTALL:
|
|
|
|
; Initialize variables. Just copy the default stuff over
|
|
|
|
ldx #.sizeof(DefVars)-1
|
|
@L1: lda DefVars,x
|
|
sta Vars,x
|
|
dex
|
|
bpl @L1
|
|
|
|
; Make sure the mouse cursor is at the default location.
|
|
|
|
lda XPos
|
|
sta XPosWrk
|
|
ldx XPos+1
|
|
stx XPosWrk+1
|
|
jsr CMOVEX
|
|
lda YPos
|
|
sta YPosWrk
|
|
ldx YPos+1
|
|
stx YPosWrk+1
|
|
jsr CMOVEY
|
|
|
|
; Install timer irq routine to poll mouse.
|
|
|
|
.ifdef __ATARIXL__
|
|
|
|
; Setup pointer to wrapper install/deinstall function.
|
|
lda libref
|
|
sta set_VTIMR2_handler+1
|
|
lda libref+1
|
|
sta set_VTIMR2_handler+2
|
|
|
|
; Install my handler.
|
|
sec
|
|
lda #<T2Han
|
|
ldx #>T2Han
|
|
jsr set_VTIMR2_handler
|
|
|
|
.else
|
|
|
|
lda VTIMR2
|
|
sta OldT2
|
|
lda VTIMR2+1
|
|
sta OldT2+1
|
|
|
|
php
|
|
sei
|
|
lda #<T2Han
|
|
sta VTIMR2
|
|
lda #>T2Han
|
|
sta VTIMR2+1
|
|
plp
|
|
|
|
.endif
|
|
|
|
lda #%00000001
|
|
sta AUDCTL
|
|
|
|
lda #0
|
|
sta AUDC2
|
|
|
|
lda #15
|
|
sta AUDF2
|
|
sta STIMER
|
|
|
|
lda PORTA
|
|
and #$0f
|
|
sta old_porta_vbi
|
|
|
|
; Done
|
|
|
|
ldx #MOUSE_ERR_OK
|
|
.assert MOUSE_ERR_OK = 0, error
|
|
txa
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; UNINSTALL routine. Is called before the driver is removed from memory.
|
|
; No return code required (the driver is removed from memory on return).
|
|
|
|
UNINSTALL:
|
|
|
|
; uninstall timer irq routine
|
|
|
|
lda POKMSK
|
|
and #%11111101 ; timer 2 disable
|
|
sta IRQEN
|
|
sta POKMSK
|
|
|
|
.ifdef __ATARIXL__
|
|
|
|
clc
|
|
jsr set_VTIMR2_handler
|
|
|
|
.else
|
|
|
|
php
|
|
sei
|
|
lda OldT2
|
|
sta VTIMR2
|
|
lda OldT2+1
|
|
sta VTIMR2+1
|
|
plp
|
|
|
|
.endif
|
|
; fall thru...
|
|
|
|
;----------------------------------------------------------------------------
|
|
; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
|
|
; a counter for calls to show/hide, and the driver entry point is only called
|
|
; if the mouse is currently visible and should get hidden. For most drivers,
|
|
; no special action is required besides hiding the mouse cursor.
|
|
; No return code required.
|
|
|
|
HIDE: php
|
|
sei
|
|
jsr CHIDE
|
|
plp
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
|
|
; a counter for calls to show/hide, and the driver entry point is only called
|
|
; if the mouse is currently hidden and should become visible. For most drivers,
|
|
; no special action is required besides enabling the mouse cursor.
|
|
; No return code required.
|
|
|
|
SHOW: php
|
|
sei
|
|
jsr CSHOW
|
|
plp
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; SETBOX: Set the mouse bounding box. The parameters are passed as they come
|
|
; from the C program, that is, a pointer to a mouse_box struct in a/x.
|
|
; No checks are done if the mouse is currently inside the box, this is the job
|
|
; of the caller. It is not necessary to validate the parameters, trust the
|
|
; caller and save some code here. No return code required.
|
|
|
|
SETBOX: sta ptr1
|
|
stx ptr1+1 ; Save data pointer
|
|
|
|
ldy #.sizeof (MOUSE_BOX)-1
|
|
php
|
|
sei
|
|
|
|
@L1: lda (ptr1),y
|
|
sta XMin,y
|
|
dey
|
|
bpl @L1
|
|
|
|
plp
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; GETBOX: Return the mouse bounding box. The parameters are passed as they
|
|
; come from the C program, that is, a pointer to a mouse_box struct in a/x.
|
|
|
|
GETBOX: sta ptr1
|
|
stx ptr1+1 ; Save data pointer
|
|
|
|
ldy #.sizeof (MOUSE_BOX)-1
|
|
php
|
|
sei
|
|
|
|
@L1: lda XMin,y
|
|
sta (ptr1),y
|
|
dey
|
|
bpl @L1
|
|
|
|
plp
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; MOVE: Move the mouse to a new position. The position is passed as it comes
|
|
; from the C program, that is: X on the stack and Y in a/x. The C wrapper will
|
|
; remove the parameter from the stack on return.
|
|
; No checks are done if the new position is valid (within the bounding box or
|
|
; the screen). No return code required.
|
|
;
|
|
|
|
MOVE: php
|
|
sei ; No interrupts
|
|
|
|
pha
|
|
txa
|
|
pha
|
|
jsr CPREP
|
|
pla
|
|
tax
|
|
pla
|
|
|
|
sta YPos
|
|
sta YPosWrk
|
|
stx YPos+1 ; New Y position
|
|
stx YPosWrk+1
|
|
jsr CMOVEY ; Set it
|
|
|
|
ldy #$01
|
|
lda (sp),y
|
|
sta XPos+1
|
|
sta XPosWrk+1
|
|
tax
|
|
dey
|
|
lda (sp),y
|
|
sta XPos ; New X position
|
|
sta XPosWrk
|
|
jsr CMOVEX ; Move the cursor
|
|
|
|
jsr CDRAW
|
|
|
|
plp ; Restore interrupt flag
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; BUTTONS: Return the button mask in a/x.
|
|
|
|
BUTTONS:
|
|
lda Buttons
|
|
ldx #$00
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
|
|
; No return code required.
|
|
|
|
POS: ldy #MOUSE_POS::XCOORD ; Structure offset
|
|
|
|
php
|
|
sei ; Disable interrupts
|
|
lda XPos ; Transfer the position
|
|
sta (ptr1),y
|
|
lda XPos+1
|
|
iny
|
|
sta (ptr1),y
|
|
lda YPos
|
|
iny
|
|
sta (ptr1),y
|
|
lda YPos+1
|
|
plp ; Restore interrupt flag
|
|
|
|
iny
|
|
sta (ptr1),y ; Store last byte
|
|
|
|
rts ; Done
|
|
|
|
;----------------------------------------------------------------------------
|
|
; INFO: Returns mouse position and current button mask in the MOUSE_INFO
|
|
; struct pointed to by ptr1. No return code required.
|
|
;
|
|
; We're cheating here to keep the code smaller: The first fields of the
|
|
; mouse_info struct are identical to the mouse_pos struct, so we will just
|
|
; call _mouse_pos to initialize the struct pointer and fill the position
|
|
; fields.
|
|
|
|
INFO: jsr POS
|
|
|
|
; Fill in the button state
|
|
|
|
lda Buttons
|
|
ldy #MOUSE_INFO::BUTTONS
|
|
sta (ptr1),y
|
|
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
|
|
; specific data in ptr1, and the ioctl code in A.
|
|
; Must return an error code in a/x.
|
|
;
|
|
|
|
IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
|
|
ldx #>MOUSE_ERR_INV_IOCTL
|
|
rts
|
|
|
|
;----------------------------------------------------------------------------
|
|
; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
|
|
; (so be careful). The routine MUST return carry set if the interrupt has been
|
|
; 'handled' - which means that the interrupt source is gone. Otherwise it
|
|
; MUST return carry clear.
|
|
;
|
|
|
|
IRQ: lda PORTA ; mouse port contents
|
|
and #$0f ; check port 1 only
|
|
ldx irq_enabled
|
|
bne @L1
|
|
|
|
; IRQ is disabled, check for mouse motion and enable IRQ if mouse motion detected
|
|
|
|
cmp old_porta_vbi
|
|
beq @L3 ; no motion
|
|
lda #0
|
|
sta ATRACT ; disable "attract mode"
|
|
|
|
; Turn mouse polling IRQ back on
|
|
|
|
lda POKMSK
|
|
ora #%00000010 ; timer 2 enable
|
|
sta POKMSK
|
|
sta IRQEN
|
|
sta irq_enabled
|
|
bne @L3
|
|
; not reached
|
|
|
|
; IRQ is enabled
|
|
|
|
@L1: cmp old_porta_vbi ; mouse motion since last VBI?
|
|
sta old_porta_vbi
|
|
beq @L2 ; no, increment timeout to disable IRQ
|
|
|
|
lda #0
|
|
sta how_long ; yes, reinitialize wait counter
|
|
beq @L3
|
|
; not reached
|
|
|
|
@L2: inc how_long ; no motion, increment wait counter
|
|
lda how_long
|
|
cmp #DISABLE_TIMEOUT ; timeout?
|
|
bcc @L3 ; no
|
|
|
|
lda #0 ; yes, turn off IRQ
|
|
sta how_long
|
|
|
|
; no mouse input -- turn IRQ off
|
|
|
|
sta irq_enabled
|
|
lda POKMSK
|
|
and #%11111101 ; timer 2 disable
|
|
sta IRQEN
|
|
sta POKMSK
|
|
|
|
; Check for a pressed button and place the result into Buttons
|
|
|
|
@L3: ldx #0
|
|
lda TRIG0 ; joystick #0 trigger
|
|
bne @L4 ; not pressed
|
|
ldx #MOUSE_BTN_LEFT
|
|
@L4: stx Buttons
|
|
|
|
jsr CPREP
|
|
|
|
; Disable "attract mode" if button status has changed
|
|
|
|
lda Buttons
|
|
cmp OldButton
|
|
beq @L5
|
|
sta OldButton
|
|
lda #0
|
|
sta ATRACT
|
|
|
|
; Limit the X coordinate to the bounding box
|
|
|
|
@L5: lda XPosWrk+1
|
|
ldy XPosWrk
|
|
tax
|
|
cpy XMin
|
|
sbc XMin+1
|
|
bpl @L6
|
|
ldy XMin
|
|
ldx XMin+1
|
|
jmp @L7
|
|
|
|
@L6: txa
|
|
cpy XMax
|
|
sbc XMax+1
|
|
bmi @L7
|
|
ldy XMax
|
|
ldx XMax+1
|
|
@L7: sty XPos
|
|
stx XPos+1
|
|
tya
|
|
jsr CMOVEX
|
|
|
|
; Limit the Y coordinate to the bounding box
|
|
|
|
lda YPosWrk+1
|
|
ldy YPosWrk
|
|
tax
|
|
cpy YMin
|
|
sbc YMin+1
|
|
bpl @L8
|
|
ldy YMin
|
|
ldx YMin+1
|
|
jmp @L9
|
|
|
|
@L8: txa
|
|
cpy YMax
|
|
sbc YMax+1
|
|
bmi @L9
|
|
ldy YMax
|
|
ldx YMax+1
|
|
@L9: sty YPos
|
|
stx YPos+1
|
|
tya
|
|
jsr CMOVEY
|
|
|
|
jsr CDRAW
|
|
|
|
.ifdef DEBUG
|
|
; print on upper right corner 'E' or 'D', indicating the IRQ is enabled or disabled
|
|
ldy irq_enabled
|
|
beq @L10
|
|
lda #37 ; screen code for 'E'
|
|
.byte $2c ; bit opcode, eats next 2 bytes
|
|
@L10: lda #36 ; screen code for 'D'
|
|
ldy #39
|
|
sta (SAVMSC),y
|
|
.endif
|
|
|
|
clc
|
|
rts
|
|
|
|
|
|
;----------------------------------------------------------------------------
|
|
; T2Han: Local IRQ routine to poll mouse
|
|
;
|
|
|
|
T2Han: lda CRITIC ; if CRITIC flag is set, disable the
|
|
bne disable_me ; high frequency polling IRQ, in order
|
|
; not to interfere with SIO I/O (e.g.
|
|
; floppy access or serial I/O)
|
|
|
|
lda in_irq ; handler entered again?
|
|
bne skip ; yes, ignore this interrupt
|
|
inc in_irq
|
|
cli ; enable IRQs so that we don't block them for too long
|
|
|
|
tya
|
|
pha
|
|
txa
|
|
pha
|
|
|
|
.ifdef DEBUG
|
|
lda RANDOM
|
|
sta COLBK
|
|
.endif
|
|
|
|
lda PORTA
|
|
tay
|
|
|
|
.ifdef ST_MOUSE
|
|
|
|
; ST mouse version
|
|
|
|
and #%00000011
|
|
ora dumx
|
|
tax
|
|
lda STTab,x
|
|
bmi nxst
|
|
|
|
beq xist
|
|
|
|
dec XPosWrk
|
|
lda XPosWrk
|
|
cmp #255
|
|
bne nxst
|
|
dec XPosWrk+1
|
|
jmp nxst
|
|
|
|
xist: inc XPosWrk
|
|
bne nxst
|
|
inc XPosWrk+1
|
|
|
|
nxst: tya
|
|
and #%00001100
|
|
ora dumy
|
|
tax
|
|
lda STTab,x
|
|
bmi nyst
|
|
|
|
bne yst
|
|
|
|
dec YPosWrk
|
|
lda YPosWrk
|
|
cmp #255
|
|
bne nyst
|
|
dec YPosWrk+1
|
|
jmp nyst
|
|
|
|
yst: inc YPosWrk
|
|
bne nyst
|
|
inc YPosWrk+1
|
|
|
|
; store old readings
|
|
|
|
nyst: tya
|
|
and #%00000011
|
|
asl
|
|
asl
|
|
sta dumx
|
|
tya
|
|
and #%00001100
|
|
lsr
|
|
lsr
|
|
sta dumy
|
|
|
|
.elseif .defined (AMIGA_MOUSE)
|
|
|
|
; Amiga mouse version
|
|
|
|
lsr
|
|
and #%00000101
|
|
ora dumx
|
|
tax
|
|
lda AmiTab,x
|
|
bmi nxami
|
|
|
|
bne xiami
|
|
|
|
dec XPosWrk
|
|
lda XPosWrk
|
|
cmp #255
|
|
bne nxami
|
|
dec XPosWrk+1
|
|
jmp nxami
|
|
|
|
xiami: inc XPosWrk
|
|
bne nxami
|
|
inc XPosWrk+1
|
|
|
|
nxami: tya
|
|
|
|
and #%00000101
|
|
ora dumy
|
|
tax
|
|
lda AmiTab,x
|
|
bmi nyami
|
|
|
|
bne yiami
|
|
|
|
dec YPosWrk
|
|
lda YPosWrk
|
|
cmp #255
|
|
bne nyami
|
|
dec YPosWrk+1
|
|
jmp nyami
|
|
|
|
yiami: inc YPosWrk
|
|
bne nyami
|
|
inc YPosWrk+1
|
|
|
|
; store old readings
|
|
|
|
nyami: tya
|
|
and #%00001010
|
|
sta dumx
|
|
tya
|
|
and #%00000101
|
|
asl
|
|
sta dumy
|
|
|
|
.elseif .defined (TRAK_MOUSE)
|
|
|
|
; trakball version
|
|
|
|
eor oldval
|
|
and #%00001000
|
|
beq horiz
|
|
|
|
tya
|
|
and #%00000100
|
|
beq mmup
|
|
|
|
inc YPosWrk
|
|
bne horiz
|
|
inc YPosWrk+1
|
|
bne horiz
|
|
|
|
mmup: dec YPosWrk
|
|
lda YPosWrk
|
|
cmp #255
|
|
bne horiz
|
|
dec YPosWrk+1
|
|
|
|
horiz: tya
|
|
eor oldval
|
|
and #%00000010
|
|
beq mmexit
|
|
|
|
tya
|
|
and #%00000001
|
|
beq mmleft
|
|
|
|
inc XPosWrk
|
|
bne mmexit
|
|
inc XPosWrk+1
|
|
bne mmexit
|
|
|
|
mmleft: dec XPosWrk
|
|
lda XPosWrk
|
|
cmp #255
|
|
bne mmexit
|
|
dec XPosWrk+1
|
|
|
|
mmexit: sty oldval
|
|
|
|
.endif
|
|
|
|
pla
|
|
tax
|
|
pla
|
|
tay
|
|
dec in_irq
|
|
skip:
|
|
.ifdef __ATARIXL__
|
|
rts
|
|
.else
|
|
pla
|
|
rti
|
|
.endif
|
|
|
|
|
|
; Disable the interrupt source which caused us to be called.
|
|
; The interrupt will be enabled again by the "IRQ" routine.
|
|
; The "IRQ" routine, despite its name, is called from the
|
|
; vertical blank NMI interrupt *only* if the CRITIC flag has
|
|
; been cleared.
|
|
|
|
disable_me:
|
|
lda POKMSK
|
|
and #%11111101 ; timer 2 disable
|
|
sta IRQEN
|
|
sta POKMSK
|
|
lda #0
|
|
sta irq_enabled
|
|
lda PORTA
|
|
and #$0f
|
|
sta old_porta_vbi
|
|
.ifdef __ATARIXL__
|
|
rts
|
|
.else
|
|
pla
|
|
rti
|
|
.endif
|