2 ; Driver for the Inkwell Systems 170-C and 184-C lightpens.
4 ; 2013-06-17, Greg King
7 .include "zeropage.inc"
8 .include "mouse-kernel.inc"
13 ; ------------------------------------------------------------------------
14 ; Header. Includes jump table.
22 .byte $6d, $6f, $75 ; ASCII "mou"
23 .byte MOUSE_API_VERSION ; Mouse driver API version number
46 .byte MOUSE_FLAG_EARLY_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 co-ord.
53 CMOVEY: jmp $0000 ; Move the cursor to Y co-ord.
56 ;----------------------------------------------------------------------------
59 ; This driver is for the 40-column screen.
64 SCREEN_WIDTH = XSIZE * 8
65 SCREEN_HEIGHT = YSIZE * 8
68 ;----------------------------------------------------------------------------
69 ; Global variables. The bounding box values are sorted so that they can be
70 ; written with the least effort in the SETBOX and GETBOX routines; so, don't
75 ; Default values for below variables
76 ; (We use ".proc" because we want to define both a label and a scope.)
81 .word SCREEN_WIDTH - 1 ; XMax
82 .word SCREEN_HEIGHT - 1 ; YMax
83 .byte %00000000 ; Buttons
89 XMin: .res 2 ; X1 value of bounding box
90 YMin: .res 2 ; Y1 value of bounding box
91 XMax: .res 2 ; X2 value of bounding box
92 YMax: .res 2 ; Y2 value of bounding box
93 Buttons: .res 1 ; Button status bits
95 XPos: .res 2 ; Current lightpen position, X
96 YPos: .res 2 ; Current lightpen position, Y
98 OldPenX: .res 1 ; Previous HW-counter values
105 ; Default Inkwell calibration.
106 ; The first number is the width of the left border;
107 ; the second number is the actual calibration value.
109 XOffset: .byte (24 + 24) / 2 ; x-offset
111 ; Jump to a function that puts a new calibration value into XOffset.
117 ;----------------------------------------------------------------------------
118 ; INSTALL routine. Is called after the driver is loaded into memory. If
119 ; possible, check if the hardware is present.
120 ; Must return a MOUSE_ERR_xx code in .XA.
124 ; Disable the BASIC interpreter's interrupt-driven sprite-motion code.
125 ; That allows direct access to the VIC-IIe's sprite registers.
132 ; Initiate variables. Just copy the default stuff over.
134 ldx #.sizeof (DefVars) - 1
145 ; Call a calibration function through the library-reference.
149 sta ptr1 ; Point to mouse_adjuster
153 sta Calibrate+1 ; Point to function
157 ora Calibrate+1 ; Don't call pointer if it's NULL
159 lda #<XOffset ; Function will set this variable
163 ; Be sure that the lightpen cursor is invisible and at the default location.
164 ; It needs to be done here because the lightpen interrupt handler doesn't
165 ; set the lightpen position if it hasn't changed.
169 lda #<(SCREEN_HEIGHT / 2)
170 ldx #>(SCREEN_HEIGHT / 2)
172 lda #<(SCREEN_WIDTH / 2)
173 ldx #>(SCREEN_WIDTH / 2)
182 ;----------------------------------------------------------------------------
183 ; UNINSTALL routine. Is called before the driver is removed from memory.
184 ; No return code required (the driver is removed from memory on return).
187 jsr HIDE ; Hide cursor on exit
192 ;----------------------------------------------------------------------------
193 ; HIDE routine. Is called to hide the lightpen pointer. The mouse kernel manages
194 ; a counter for calls to show/hide, and the driver entry point is called only
195 ; if the mouse is currently visible, and should get hidden. For most drivers,
196 ; no special action is required besides hiding the lightpen cursor.
197 ; No return code required.
204 ;----------------------------------------------------------------------------
205 ; SHOW routine. Is called to show the lightpen pointer. The mouse kernel manages
206 ; a counter for calls to show/hide, and the driver entry point is called only
207 ; if the mouse is currently hidden, and should become visible. For most drivers,
208 ; no special action is required besides enabling the lightpen cursor.
209 ; No return code required.
216 ;----------------------------------------------------------------------------
217 ; SETBOX: Set the lightpen bounding box. The parameters are passed as they come
218 ; from the C program, that is, a pointer to a mouse_box struct in .XA.
219 ; No checks are done if the lightpen is currently inside the box, that is the job
220 ; of the caller. It is not necessary to validate the parameters; trust the
221 ; caller; and, save some code here. No return code required.
224 stx ptr1+1 ; Save data pointer
226 ldy #.sizeof (MOUSE_BOX) - 1
237 ;----------------------------------------------------------------------------
238 ; GETBOX: Return the lightpen bounding box. The parameters are passed as they
239 ; come from the C program, that is, a pointer to a mouse_box struct in .XA.
242 stx ptr1+1 ; Save data pointer
244 ldy #.sizeof (MOUSE_BOX) - 1
251 ;----------------------------------------------------------------------------
252 ; MOVE: Move the mouse to a new position. The position is passed as it comes
253 ; from the C program, that is: X on the stack and Y in .XA. The C wrapper will
254 ; remove the parameter from the stack on return.
255 ; No checks are done if the new position is valid (within the bounding box or
256 ; the screen). No return code required.
259 MOVE: sei ; No interrupts
267 jsr MoveX ; Move the cursor
269 cli ; Allow interrupts
272 ;----------------------------------------------------------------------------
273 ; BUTTONS: Return the button mask in .XA.
279 ; Make the lightpen buttons look like a 1351 mouse.
282 asl SID_ADConv2 ; PotY
285 and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
288 ;----------------------------------------------------------------------------
289 ; POS: Return the lightpen position in the MOUSE_POS struct pointed to by ptr1.
290 ; No return code required.
292 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
294 sei ; Disable interrupts
295 lda XPos ; Transfer the position
304 cli ; Enable interrupts
307 sta (ptr1),y ; Store last byte
310 ;----------------------------------------------------------------------------
311 ; INFO: Returns lightpen position and current button mask in the MOUSE_INFO
312 ; struct pointed to by ptr1. No return code required.
314 ; We're cheating here, to keep the code smaller: The first fields of the
315 ; mouse_info struct are identical to the mouse_pos struct; so, we'll just
316 ; call _mouse_pos to initiate the struct pointer, and fill the position
321 ; Fill in the button state
323 jsr BUTTONS ; Will not touch ptr1
324 ldy #MOUSE_INFO::BUTTONS
328 ;----------------------------------------------------------------------------
329 ; IOCTL: Driver-defined entry point. The wrapper will pass a pointer to ioctl-
330 ; specific data in ptr1, and the ioctl code in .A.
331 ; Must return an error code in .XA.
334 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioctls, for now
335 ldx #>MOUSE_ERR_INV_IOCTL
338 ;----------------------------------------------------------------------------
339 ; IRQ: IRQ handler entry point. Called as a subroutine, but in the IRQ context
340 ; (so, be careful). The routine MUST return carry set if the interrupt has been
341 ; 'handled' -- which means that the interrupt source is gone. Otherwise, it
342 ; MUST return carry clear.
347 ; Record the state of the buttons.
348 ; Try to avoid crosstalk between the keyboard and the lightpen.
350 ldy #%00000000 ; Set ports A and B to input
352 sty CIA1_DDRA ; Keyboard won't look like buttons
353 lda CIA1_PRB ; Read Control-Port 1
354 dec CIA1_DDRA ; Set port A back to output
355 eor #%11111111 ; Bit goes up when button goes down
358 lda #%11101111 ; (Don't change bit that feeds VIC-II)
359 sta CIA1_DDRB ; Buttons won't look like keyboard
360 sty CIA1_PRB ; Set "all keys pushed"
362 ; Read the VIC-II lightpen registers.
367 ; Skip processing if nothing has changed.
372 ; Subtract the height of the top border, so that the lightpen co-ordinate
373 ; will match the TGI co-ordinate.
376 tay ; Remember low byte
379 ; Limit the Y co-ordinate to the bounding box.
399 @SkipY: lda VIC_LPEN_X
402 ; Skip processing if nothing has changed.
407 ; Adjust the value by the calibration offset.
411 ; Calculate the new X co-ordinate.
412 ; The VIC-II register is eight bits; but, the screen co-ordinate is nine bits.
413 ; Therefore, the VIC-II number is doubled. Then, it points to every other pixel;
414 ; but, it can reach across the screen.
417 tay ; Remember low byte
420 tax ; Remember high byte
422 ; Limit the X co-ordinate to the bounding box.
443 @SkipX: clc ; Interrupt not "handled"
446 ; Move the lightpen pointer to the new Y pos.
452 ; Move the lightpen pointer to the new X pos.