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 SCREEN_WIDTH = XSIZE * 8
60 SCREEN_HEIGHT = YSIZE * 8
63 ;----------------------------------------------------------------------------
64 ; Global variables. The bounding box values are sorted so that they can be
65 ; written with the least effort in the SETBOX and GETBOX routines; so, don't
70 ; Default values for below variables
71 ; (We use ".proc" because we want to define both a label and a scope.)
76 .word SCREEN_WIDTH - 1 ; XMax
77 .word SCREEN_HEIGHT - 1 ; YMax
78 .byte %00000000 ; Buttons
84 XMin: .res 2 ; X1 value of bounding box
85 YMin: .res 2 ; Y1 value of bounding box
86 XMax: .res 2 ; X2 value of bounding box
87 YMax: .res 2 ; Y2 value of bounding box
88 Buttons: .res 1 ; Button status bits
90 XPos: .res 2 ; Current lightpen position, X
91 YPos: .res 2 ; Current lightpen position, Y
93 OldPenX: .res 1 ; Previous HW-counter values
98 ; Default Inkwell calibration.
99 ; The first number is the width of the left border;
100 ; the second number is the actual calibration value.
102 XOffset: .byte (24 + 24) / 2 ; x-offset
104 ; Jump to a function that puts a new calibration value into XOffset.
110 ;----------------------------------------------------------------------------
111 ; INSTALL routine. Is called after the driver is loaded into memory. If
112 ; possible, check if the hardware is present.
113 ; Must return a MOUSE_ERR_xx code in .XA.
117 ; Initiate variables. Just copy the default stuff over.
119 ldx #.sizeof (DefVars) - 1
130 ; Call a calibration function through the library-reference.
134 sta ptr1 ; Point to mouse_adjuster
138 sta Calibrate+1 ; Point to function
142 ora Calibrate+1 ; Don't call pointer if it's NULL
144 lda #<XOffset ; Function will set this variable
148 ; Be sure that the lightpen cursor is invisible and at the default location.
149 ; It needs to be done here because the lightpen interrupt handler doesn't
150 ; set the lightpen position if it hasn't changed.
154 lda #<(SCREEN_HEIGHT / 2)
155 ldx #>(SCREEN_HEIGHT / 2)
157 lda #<(SCREEN_WIDTH / 2)
158 ldx #>(SCREEN_WIDTH / 2)
167 ;----------------------------------------------------------------------------
168 ; UNINSTALL routine. Is called before the driver is removed from memory.
169 ; No return code required (the driver is removed from memory on return).
171 UNINSTALL := HIDE ; Hide cursor on exit
173 ;----------------------------------------------------------------------------
174 ; HIDE routine. Is called to hide the lightpen pointer. The mouse kernel manages
175 ; a counter for calls to show/hide, and the driver entry point is called only
176 ; if the mouse is currently visible, and should get hidden. For most drivers,
177 ; no special action is required besides hiding the lightpen cursor.
178 ; No return code required.
185 ;----------------------------------------------------------------------------
186 ; SHOW routine. Is called to show the lightpen pointer. The mouse kernel manages
187 ; a counter for calls to show/hide, and the driver entry point is called only
188 ; if the mouse is currently hidden, and should become visible. For most drivers,
189 ; no special action is required besides enabling the lightpen cursor.
190 ; No return code required.
197 ;----------------------------------------------------------------------------
198 ; SETBOX: Set the lightpen bounding box. The parameters are passed as they come
199 ; from the C program, that is, a pointer to a mouse_box struct in .XA.
200 ; No checks are done if the lightpen is currently inside the box, that is the job
201 ; of the caller. It is not necessary to validate the parameters; trust the
202 ; caller; and, save some code here. No return code required.
205 stx ptr1+1 ; Save data pointer
207 ldy #.sizeof (MOUSE_BOX) - 1
218 ;----------------------------------------------------------------------------
219 ; GETBOX: Return the lightpen bounding box. The parameters are passed as they
220 ; come from the C program, that is, a pointer to a mouse_box struct in .XA.
223 stx ptr1+1 ; Save data pointer
225 ldy #.sizeof (MOUSE_BOX) - 1
232 ;----------------------------------------------------------------------------
233 ; MOVE: Move the mouse to a new position. The position is passed as it comes
234 ; from the C program, that is: X on the stack and Y in .XA. The C wrapper will
235 ; remove the parameter from the stack on return.
236 ; No checks are done if the new position is valid (within the bounding box or
237 ; the screen). No return code required.
240 MOVE: sei ; No interrupts
248 jsr MoveX ; Move the cursor
250 cli ; Allow interrupts
253 ;----------------------------------------------------------------------------
254 ; BUTTONS: Return the button mask in .XA.
260 ; Make the lightpen buttons look like a 1351 mouse.
263 asl SID_ADConv2 ; PotY
266 and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
269 ;----------------------------------------------------------------------------
270 ; POS: Return the lightpen position in the MOUSE_POS struct pointed to by ptr1.
271 ; No return code required.
273 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
275 sei ; Disable interrupts
276 lda XPos ; Transfer the position
285 cli ; Enable interrupts
288 sta (ptr1),y ; Store last byte
291 ;----------------------------------------------------------------------------
292 ; INFO: Returns lightpen position and current button mask in the MOUSE_INFO
293 ; struct pointed to by ptr1. No return code required.
295 ; We're cheating here, to keep the code smaller: The first fields of the
296 ; mouse_info struct are identical to the mouse_pos struct; so, we'll just
297 ; call _mouse_pos to initiate the struct pointer, and fill the position
302 ; Fill in the button state
304 jsr BUTTONS ; Will not touch ptr1
305 ldy #MOUSE_INFO::BUTTONS
309 ;----------------------------------------------------------------------------
310 ; IOCTL: Driver-defined entry point. The wrapper will pass a pointer to ioctl-
311 ; specific data in ptr1, and the ioctl code in .A.
312 ; Must return an error code in .XA.
315 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioctls, for now
316 ldx #>MOUSE_ERR_INV_IOCTL
319 ;----------------------------------------------------------------------------
320 ; IRQ: IRQ handler entry point. Called as a subroutine, but in the IRQ context
321 ; (so, be careful). The routine MUST return carry set if the interrupt has been
322 ; 'handled' -- which means that the interrupt source is gone. Otherwise, it
323 ; MUST return carry clear.
328 ; Record the state of the buttons.
329 ; Try to avoid crosstalk between the keyboard and the lightpen.
331 ldy #%00000000 ; Set ports A and B to input
333 sty CIA1_DDRA ; Keyboard won't look like buttons
334 lda CIA1_PRB ; Read Control-Port 1
335 dec CIA1_DDRA ; Set port A back to output
336 eor #%11111111 ; Bit goes up when button goes down
339 lda #%11101111 ; (Don't change bit that feeds VIC-II)
340 sta CIA1_DDRB ; Buttons won't look like keyboard
341 sty CIA1_PRB ; Set "all keys pushed"
343 ; Read the VIC-II lightpen registers.
348 ; Skip processing if nothing has changed.
353 ; Subtract the height of the top border, so that the lightpen co-ordinate
354 ; will match the TGI co-ordinate.
357 tay ; Remember low byte
360 ; Limit the Y co-ordinate to the bounding box.
380 @SkipY: lda VIC_LPEN_X
383 ; Skip processing if nothing has changed.
388 ; Adjust the value by the calibration offset.
392 ; Calculate the new X co-ordinate.
393 ; The VIC-II register is eight bits; but, the screen co-ordinate is nine bits.
394 ; Therefore, the VIC-II number is doubled. Then, it points to every other pixel;
395 ; but, it can reach across the screen.
398 tay ; Remember low byte
401 tax ; Remember high byte
403 ; Limit the X co-ordinate to the bounding box.
424 @SkipX: clc ; Interrupt not "handled"
427 ; Move the lightpen pointer to the new Y pos.
433 ; Move the lightpen pointer to the new X pos.