; ; Driver for the 1351 proportional mouse. Parts of the code are from ; the Commodore 1351 mouse users guide. ; ; 2009-09-26, Ullrich von Bassewitz ; 2010-02-06, Greg King ; ; The driver prevents the keyboard from interfering by changing the ; keyboard's output port into an input port while the driver reads its ; controller device. That disables a wire that is left active by the ; Kernal. That wire is used by the STOP-key to break out of BASIC ; programs -- CC65 programs don't use that feature. The wire is shared ; by these keys: STOP, "Q", Commodore, Space, "2", CTRL, Left-Arrow, and ; "1". I listed them, in order, from bit 7 over to bit 0. The ; rightmost five keys can look like joystick switches. ; ; The driver prevents the mouse/joystick from interfering by "blinding" ; the keyboard scanner while any button/switch is active. It changes ; the input port into an output port, then stores all zero-bits in that ; port's latch. Reading from an output port sees the bitwise-AND of the ; latch and the input signals. Therefore, the scanner thinks that eight ; keys are being pushed at the same time. It doesn't know what to do ; about that condition; so, it does nothing. The driver lets the ; scanner see normally, again, when no buttons/switches are active. ; .include "zeropage.inc" .include "mouse-kernel.inc" .include "c64.inc" .macpack generic .macpack module ; ------------------------------------------------------------------------ ; Header. Includes jump table module_header _c64_1351_mou HEADER: ; Driver signature .byte $6d, $6f, $75 ; "mou" .byte MOUSE_API_VERSION ; Mouse driver API version number ; Library reference .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 = YSIZE * 8 - 1 ; (origin is zero) SCREEN_WIDTH = XSIZE * 8 - 1 ;---------------------------------------------------------------------------- ; 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: OldPotX: .res 1 ; Old hw counter values OldPotY: .res 1 XPos: .res 2 ; Current mouse position, X YPos: .res 2 ; Current mouse position, Y 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 status bits OldValue: .res 1 ; Temp for MoveCheck routine NewValue: .res 1 ; Temp for MoveCheck routine .rodata ; Default values for above variables ; (We use ".proc" because we want to define both a label and a scope.) .proc DefVars .byte 0, 0 ; OldPotX/OldPotY .word SCREEN_WIDTH/2 ; XPos .word SCREEN_HEIGHT/2 ; YPos .word 0 ; XMin .word 0 ; YMin .word SCREEN_WIDTH ; XMax .word SCREEN_HEIGHT ; YMax .byte %00000000 ; Buttons .endproc .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 ; Be sure the mouse cursor is invisible and at the default location. We ; need to do that here, because our mouse interrupt handler doesn't set the ; mouse position if it hasn't changed. sei jsr CHIDE lda XPos ldx XPos+1 jsr CMOVEX lda YPos ldx YPos+1 jsr CMOVEY cli ; 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 = HIDE ; Hide cursor on exit ;---------------------------------------------------------------------------- ; 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: sei jsr CHIDE cli 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: sei jsr CSHOW cli 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 sei @L1: lda (ptr1),y sta XMin,y dey bpl @L1 cli 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 @L1: lda XMin,y sta (ptr1),y dey bpl @L1 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: sei ; No interrupts sta YPos stx YPos+1 ; New Y position jsr CMOVEY ; Set it ldy #$01 lda (sp),y sta XPos+1 tax dey lda (sp),y sta XPos ; New X position jsr CMOVEX ; Move the cursor cli ; Allow interrupts rts ;---------------------------------------------------------------------------- ; BUTTONS: Return the button mask in a/x. BUTTONS: lda Buttons ldx #0 and #$1F 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 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 cli ; Enable interrupts 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 jsr BUTTONS ; Will not touch ptr1 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 #0 ; return value is char 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: jsr CPREP ; Record the state of the buttons. ; Avoid crosstalk between the keyboard and the mouse. ldy #%00000000 ; Set ports A and B to input sty CIA1_DDRB sty CIA1_DDRA ; Keyboard won't look like mouse lda CIA1_PRB ; Read Control-Port 1 dec CIA1_DDRA ; Set port A back to output eor #%11111111 ; Bit goes up when button goes down sta Buttons beq @L0 ;(bze) dec CIA1_DDRB ; Mouse won't look like keyboard sty CIA1_PRB ; Set "all keys pushed" @L0: lda SID_ADConv1 ; Get mouse X movement ldy OldPotX jsr MoveCheck ; Calculate movement vector ; Skip processing if nothing has changed bcc @SkipX sty OldPotX ; Calculate the new X coordinate (--> a/y) add XPos tay ; Remember low byte txa adc XPos+1 tax ; Limit the X coordinate to the bounding box cpy XMin sbc XMin+1 bpl @L1 ldy XMin ldx XMin+1 jmp @L2 @L1: txa cpy XMax sbc XMax+1 bmi @L2 ldy XMax ldx XMax+1 @L2: sty XPos stx XPos+1 ; Move the mouse pointer to the new X pos tya jsr CMOVEX ; Calculate the Y movement vector @SkipX: lda SID_ADConv2 ; Get mouse Y movement ldy OldPotY jsr MoveCheck ; Calculate movement ; Skip processing if nothing has changed bcc @SkipY sty OldPotY ; Calculate the new Y coordinate (--> a/y) sta OldValue lda YPos sub OldValue tay stx OldValue lda YPos+1 sbc OldValue tax ; Limit the Y coordinate to the bounding box cpy YMin sbc YMin+1 bpl @L3 ldy YMin ldx YMin+1 jmp @L4 @L3: txa cpy YMax sbc YMax+1 bmi @L4 ldy YMax ldx YMax+1 @L4: sty YPos stx YPos+1 ; Move the mouse pointer to the new Y pos tya jsr CMOVEY ; Done @SkipY: jsr CDRAW clc ; Interrupt not "handled" rts ; -------------------------------------------------------------------------- ; ; Move check routine, called for both coordinates. ; ; Entry: y = old value of pot register ; a = current value of pot register ; Exit: y = value to use for old value ; x/a = delta value for position ; MoveCheck: sty OldValue sta NewValue ldx #$00 sub OldValue ; a = mod64 (new - old) and #%01111111 cmp #%01000000 ; if (a > 0) bcs @L1 ; lsr a ; a /= 2; beq @L2 ; if (a != 0) ldy NewValue ; y = NewValue sec rts ; return @L1: ora #%11000000 ; else, "or" in high-order bits cmp #$FF ; if (a != -1) beq @L2 sec ror a ; a /= 2 dex ; high byte = -1 (X = $FF) ldy NewValue sec rts @L2: txa ; A = $00 clc rts