2 ; Driver for the Inkwell Systems 170-C and 184-C lightpens.
4 ; 2013-07-01, 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 CPREP: jmp $0000 ; Prepare to move the cursor
53 CDRAW: jmp $0000 ; Draw the cursor
54 CMOVEX: jmp $0000 ; Move the cursor to X co-ord.
55 CMOVEY: jmp $0000 ; Move the cursor to Y co-ord.
58 ;----------------------------------------------------------------------------
61 SCREEN_WIDTH = XSIZE * 8
62 SCREEN_HEIGHT = YSIZE * 8
65 ;----------------------------------------------------------------------------
66 ; Global variables. The bounding box values are sorted so that they can be
67 ; written with the least effort in the SETBOX and GETBOX routines; so, don't
72 ; Default values for below variables
73 ; (We use ".proc" because we want to define both a label and a scope.)
78 .word SCREEN_WIDTH - 1 ; XMax
79 .word SCREEN_HEIGHT - 1 ; YMax
80 .byte %00000000 ; Buttons
86 XMin: .res 2 ; X1 value of bounding box
87 YMin: .res 2 ; Y1 value of bounding box
88 XMax: .res 2 ; X2 value of bounding box
89 YMax: .res 2 ; Y2 value of bounding box
90 Buttons: .res 1 ; Button status bits
92 XPos: .res 2 ; Current lightpen position, X
93 YPos: .res 2 ; Current lightpen position, Y
95 OldPenX: .res 1 ; Previous HW-counter values
100 ; Default Inkwell calibration.
101 ; The first number is the width of the left border;
102 ; the second number is the actual calibration value.
104 XOffset: .byte (24 + 24) / 2 ; x-offset
106 ; Jump to a function that puts a new calibration value into XOffset.
112 ;----------------------------------------------------------------------------
113 ; INSTALL routine. Is called after the driver is loaded into memory. If
114 ; possible, check if the hardware is present.
115 ; Must return a MOUSE_ERR_xx code in .XA.
119 ; Initiate variables. Just copy the default stuff over.
121 ldx #.sizeof (DefVars) - 1
132 ; Call a calibration function through the library-reference.
136 sta ptr1 ; Point to mouse_adjuster
140 bze @L1 ; Don't call pointer if it's NULL
141 sta Calibrate+2 ; Point to function
145 lda #<XOffset ; Function will set this variable
149 ; Be sure that the lightpen cursor is invisible and at the default location.
150 ; It needs to be done here because the lightpen interrupt handler doesn't
151 ; set the lightpen position if it hasn't changed.
156 lda #<(SCREEN_HEIGHT / 2)
157 ldx #>(SCREEN_HEIGHT / 2)
159 lda #<(SCREEN_WIDTH / 2)
160 ldx #>(SCREEN_WIDTH / 2)
170 ;----------------------------------------------------------------------------
171 ; UNINSTALL routine. Is called before the driver is removed from memory.
172 ; No return code required (the driver is removed from memory on return).
174 UNINSTALL := HIDE ; Hide cursor on exit
176 ;----------------------------------------------------------------------------
177 ; HIDE routine. Is called to hide the lightpen pointer. The mouse kernel manages
178 ; a counter for calls to show/hide, and the driver entry point is called only
179 ; if the mouse is currently visible, and should get hidden. For most drivers,
180 ; no special action is required besides hiding the lightpen cursor.
181 ; No return code required.
188 ;----------------------------------------------------------------------------
189 ; SHOW routine. Is called to show the lightpen pointer. The mouse kernel manages
190 ; a counter for calls to show/hide, and the driver entry point is called only
191 ; if the mouse is currently hidden, and should become visible. For most drivers,
192 ; no special action is required besides enabling the lightpen cursor.
193 ; No return code required.
200 ;----------------------------------------------------------------------------
201 ; SETBOX: Set the lightpen bounding box. The parameters are passed as they come
202 ; from the C program, that is, a pointer to a mouse_box struct in .XA.
203 ; No checks are done if the lightpen is currently inside the box, that is the job
204 ; of the caller. It is not necessary to validate the parameters; trust the
205 ; caller; and, save some code here. No return code required.
208 stx ptr1+1 ; Save data pointer
210 ldy #.sizeof (MOUSE_BOX) - 1
221 ;----------------------------------------------------------------------------
222 ; GETBOX: Return the lightpen bounding box. The parameters are passed as they
223 ; come from the C program, that is, a pointer to a mouse_box struct in .XA.
226 stx ptr1+1 ; Save data pointer
228 ldy #.sizeof (MOUSE_BOX) - 1
235 ;----------------------------------------------------------------------------
236 ; MOVE: Move the mouse to a new position. The position is passed as it comes
237 ; from the C program, that is: X on the stack and Y in .XA. The C wrapper will
238 ; remove the parameter from the stack on return.
239 ; No checks are done if the new position is valid (within the bounding box or
240 ; the screen). No return code required.
243 MOVE: sei ; No interrupts
251 jsr MoveX ; Move the cursor
253 cli ; Allow interrupts
256 ;----------------------------------------------------------------------------
257 ; BUTTONS: Return the button mask in .XA.
263 ; Make the lightpen buttons look like a 1351 mouse.
266 asl SID_ADConv2 ; PotY
269 and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
272 ;----------------------------------------------------------------------------
273 ; POS: Return the lightpen position in the MOUSE_POS struct pointed to by ptr1.
274 ; No return code required.
276 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
278 sei ; Disable interrupts
279 lda XPos ; Transfer the position
288 cli ; Enable interrupts
291 sta (ptr1),y ; Store last byte
294 ;----------------------------------------------------------------------------
295 ; INFO: Returns lightpen position and current button mask in the MOUSE_INFO
296 ; struct pointed to by ptr1. No return code required.
298 ; We're cheating here, to keep the code smaller: The first fields of the
299 ; mouse_info struct are identical to the mouse_pos struct; so, we'll just
300 ; call _mouse_pos to initiate the struct pointer, and fill the position
305 ; Fill in the button state
307 jsr BUTTONS ; Will not touch ptr1
308 ldy #MOUSE_INFO::BUTTONS
312 ;----------------------------------------------------------------------------
313 ; IOCTL: Driver-defined entry point. The wrapper will pass a pointer to ioctl-
314 ; specific data in ptr1, and the ioctl code in .A.
315 ; Must return an error code in .XA.
318 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioctls, for now
319 ldx #>MOUSE_ERR_INV_IOCTL
322 ;----------------------------------------------------------------------------
323 ; IRQ: IRQ handler entry point. Called as a subroutine, but in the IRQ context
324 ; (so, be careful). The routine MUST return carry set if the interrupt has been
325 ; 'handled' -- which means that the interrupt source is gone. Otherwise, it
326 ; MUST return carry clear.
331 ; Record the state of the buttons.
332 ; Try to avoid crosstalk between the keyboard and the lightpen.
334 ldy #%00000000 ; Set ports A and B to input
336 sty CIA1_DDRA ; Keyboard won't look like buttons
337 lda CIA1_PRB ; Read Control-Port 1
338 dec CIA1_DDRA ; Set port A back to output
339 eor #%11111111 ; Bit goes up when button goes down
342 lda #%11101111 ; (Don't change bit that feeds VIC-II)
343 sta CIA1_DDRB ; Buttons won't look like keyboard
344 sty CIA1_PRB ; Set "all keys pushed"
346 ; Read the VIC-II lightpen registers.
351 ; Skip processing if nothing has changed.
356 ; Subtract the height of the top border, so that the lightpen co-ordinate
357 ; will match the TGI co-ordinate.
360 tay ; Remember low byte
363 ; Limit the Y co-ordinate to the bounding box.
383 @SkipY: lda VIC_LPEN_X
386 ; Skip processing if nothing has changed.
391 ; Adjust the value by the calibration offset.
395 ; Calculate the new X co-ordinate.
396 ; The VIC-II register is eight bits; but, the screen co-ordinate is nine bits.
397 ; Therefore, the VIC-II number is doubled. Then, it points to every other pixel;
398 ; but, it can reach across the screen.
401 tay ; Remember low byte
404 tax ; Remember high byte
406 ; Limit the X co-ordinate to the bounding box.
428 clc ; Interrupt not "handled"
431 ; Move the lightpen pointer to the new Y pos.
437 ; Move the lightpen pointer to the new X pos.