2 ; Mouse driver for Atari Touch Tablet
4 ; Christian Groessler, 2014-01-05
7 .include "zeropage.inc"
8 .include "mouse-kernel.inc"
13 ; ------------------------------------------------------------------------
14 ; Header. Includes jump table
22 .byte $6d, $6f, $75 ; "mou"
23 .byte MOUSE_API_VERSION ; Mouse driver API version number
46 .byte MOUSE_FLAG_LATE_IRQ
48 ; Callback table, set by the kernel before INSTALL is called
50 CHIDE: jmp $0000 ; Hide the cursor
51 CSHOW: jmp $0000 ; Show the cursor
52 CMOVEX: jmp $0000 ; Move the cursor to X coord
53 CMOVEY: jmp $0000 ; Move the cursor to Y coord
56 ;----------------------------------------------------------------------------
69 ;----------------------------------------------------------------------------
70 ; Global variables. The bounding box values are sorted so that they can be
71 ; written with the least effort in the SETBOX and GETBOX routines, so don't
77 YPos: .res 2 ; Current mouse position, Y
78 XPos: .res 2 ; Current mouse position, X
79 XMin: .res 2 ; X1 value of bounding box
80 YMin: .res 2 ; Y1 value of bounding box
81 XMax: .res 2 ; X2 value of bounding box
82 YMax: .res 2 ; Y2 value of bounding box
83 Buttons: .res 1 ; Button mask
88 ; Default values for above variables
92 ; (We use ".proc" because we want to define both a label and a scope.)
95 .word SCREEN_HEIGHT/2 ; YPos
96 .word SCREEN_WIDTH/2 ; XPos
99 .word SCREEN_WIDTH ; XMax
100 .word SCREEN_HEIGHT ; YMax
106 ;----------------------------------------------------------------------------
107 ; INSTALL routine. Is called after the driver is loaded into memory. If
108 ; possible, check if the hardware is present.
109 ; Must return an MOUSE_ERR_xx code in a/x.
113 ; Initialize variables. Just copy the default stuff over
115 ldx #.sizeof(DefVars)-1
121 ; Be sure the mouse cursor is invisible and at the default location. We
122 ; need to do that here, because our mouse interrupt handler doesn't set the
123 ; mouse position if it hasn't changed.
136 ; Done, return zero (= MOUSE_ERR_OK)
142 ;----------------------------------------------------------------------------
143 ; UNINSTALL routine. Is called before the driver is removed from memory.
144 ; No return code required (the driver is removed from memory on return).
146 UNINSTALL = HIDE ; Hide cursor on exit
148 ;----------------------------------------------------------------------------
149 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
150 ; a counter for calls to show/hide, and the driver entry point is only called
151 ; if the mouse is currently visible and should get hidden. For most drivers,
152 ; no special action is required besides hiding the mouse cursor.
153 ; No return code required.
162 ;----------------------------------------------------------------------------
163 ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
164 ; a counter for calls to show/hide, and the driver entry point is only called
165 ; if the mouse is currently hidden and should become visible. For most drivers,
166 ; no special action is required besides enabling the mouse cursor.
167 ; No return code required.
176 ;----------------------------------------------------------------------------
177 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
178 ; from the C program, that is, a pointer to a mouse_box struct in a/x.
179 ; No checks are done if the mouse is currently inside the box, this is the job
180 ; of the caller. It is not necessary to validate the parameters, trust the
181 ; caller and save some code here. No return code required.
184 stx ptr1+1 ; Save data pointer
186 ldy #.sizeof (MOUSE_BOX)-1
198 ;----------------------------------------------------------------------------
199 ; GETBOX: Return the mouse bounding box. The parameters are passed as they
200 ; come from the C program, that is, a pointer to a mouse_box struct in a/x.
203 stx ptr1+1 ; Save data pointer
205 ldy #.sizeof (MOUSE_BOX)-1
217 ;----------------------------------------------------------------------------
218 ; MOVE: Move the mouse to a new position. The position is passed as it comes
219 ; from the C program, that is: X on the stack and Y in a/x. The C wrapper will
220 ; remove the parameter from the stack on return.
221 ; No checks are done if the new position is valid (within the bounding box or
222 ; the screen). No return code required.
239 stx YPos+1 ; New Y position
248 sta XPos ; New X position
250 jsr CMOVEX ; Move the cursor
257 @Ret: plp ; Restore interrupt flag
260 ;----------------------------------------------------------------------------
261 ; BUTTONS: Return the button mask in a/x.
268 ;----------------------------------------------------------------------------
269 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
270 ; No return code required.
272 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
275 sei ; Disable interrupts
276 lda XPos ; Transfer the position
285 plp ; Restore interrupt flag
288 sta (ptr1),y ; Store last byte
292 ;----------------------------------------------------------------------------
293 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
294 ; struct pointed to by ptr1. No return code required.
296 ; We're cheating here to keep the code smaller: The first fields of the
297 ; mouse_info struct are identical to the mouse_pos struct, so we will just
298 ; call _mouse_pos to initialize the struct pointer and fill the position
303 ; Fill in the button state
306 ldy #MOUSE_INFO::BUTTONS
311 ;----------------------------------------------------------------------------
312 ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
313 ; specific data in ptr1, and the ioctl code in A.
314 ; Must return an error code in a/x.
317 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
318 ldx #>MOUSE_ERR_INV_IOCTL
321 ;----------------------------------------------------------------------------
322 ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
323 ; (so be careful). The routine MUST return carry set if the interrupt has been
324 ; 'handled' - which means that the interrupt source is gone. Otherwise it
325 ; MUST return carry clear.
330 ; Check for a pressed button and place the result into Buttons
335 lda PORTA ; get other buttons
338 and #5 ; pen button and left button are mapped to left mouse button
350 ; If we read 228 for X or Y positions, we assume the user has lifted the pen
351 ; and don't change the cursor position.
369 ; Get cursor position
370 ; -------------------
371 ; The touch pad is read thru the paddle potentiometers. The possible
372 ; values are 1..228. Since the maximum value is less than the X
373 ; dimension we have to "stretch" this value. In order to use only
374 ; divisions by powers of two, we use the following appoximation:
376 ; 1+1/2-1/8+1/32 = 1.4062
377 ; For Y we subtract 1/8 of it to get in the YMax ballpark.
379 ; A small area in the Y dimension of the touchpad isn't used with
380 ; this approximation. The Y value is inverted, (0,0) is the bottom
381 ; left corner of the touchpad.
385 ldx PADDL0 ; get X postion
386 dex ; decrement, since it's 1-based
397 lsr a ; port value / 4
398 lsr a ; port value / 8
408 lsr a ; port value / 16
409 lsr a ; port value / 32
420 ; Limit the X coordinate to the bounding box
438 ; Move the mouse pointer to the new X pos
445 ldx PADDL1 ; get Y postion
446 dex ; decrement, since it's 1-based
450 sbc YPos ; invert value
464 ; Limit the Y coordinate to the bounding box
482 ; Move the mouse pointer to the new X pos
491 @Done: clc ; Interrupt not "handled"