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byte mode, dtack safety
[megadrive.git] / hexed / hexed.s
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4db6e09f 1##################################################
2# #
3# Assemble with gas #
4# --register-prefix-optional --bitwise-or #
5# #
6##################################################
7
8.text
9.globl main
1286a1ba 10.globl VBL
4db6e09f 11
12##################################################
13# #
14# Register and bitmask definitions #
15# #
16##################################################
17
18.equ GFXDATA, 0xc00000
19.equ GFXCNTL, 0xc00004
20
21.equ VDP0_E_HBI, 0x10
22.equ VDP0_E_DISPLAY, 0x02
23.equ VDP0_PLTT_FULL, 0x04
24
25.equ VDP1_SMS_MODE, 0x80
26.equ VDP1_E_DISPLAY, 0x40
27.equ VDP1_E_VBI, 0x20
28.equ VDP1_E_DMA, 0x10
29.equ VDP1_NTSC, 0x00
30.equ VDP1_PAL, 0x08
31.equ VDP1_RESERVED, 0x04
32
fbad1b76 33.equ VDP12_STE, 0x08
4db6e09f 34.equ VDP12_SCREEN_V224, 0x00
35.equ VDP12_SCREEN_V448, 0x04
36.equ VDP12_PROGRESSIVE, 0x00
37.equ VDP12_INTERLACED, 0x02
38.equ VDP12_SCREEN_H256, 0x00
39.equ VDP12_SCREEN_H320, 0x81
40
41.equ VDP16_MAP_V32, 0x00
42.equ VDP16_MAP_V64, 0x10
43.equ VDP16_MAP_V128, 0x30
44.equ VDP16_MAP_H32, 0x00
45.equ VDP16_MAP_H64, 0x01
46.equ VDP16_MAP_H128, 0x03
47
4dfddc2f 48.equ MMODE_MAIN, 0
49.equ MMODE_VAL_INPUT, 1
50.equ MMODE_EDIT_VAL, 2
51.equ MMODE_GOTO, 3
27d5cc88 52.equ MMODE_START_MENU, 4
53.equ MMODE_GOTO_PREDEF, 5
4db6e09f 54
27d5cc88 55.equ predef_addr_cnt, ((predef_addrs_end-predef_addrs)/4)
4db6e09f 56
57##################################################
58# #
59# MACROS #
60# #
61##################################################
62
63
27d5cc88 64# Write val to VDP register reg
65.macro write_vdp_r_dst reg val dst
66 move.w #((\reg << 8) + 0x8000 + \val),\dst
4db6e09f 67.endm
68
27d5cc88 69# Write val to VDP register reg, vdp addr in a3
70.macro write_vdp_reg reg val
71 write_vdp_r_dst \reg, \val, (a3)
72.endm
4db6e09f 73
74/* For immediate addresses */
75.macro VRAM_ADDR reg adr
76 move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
77.endm
78
0fc4f06b 79.macro CRAM_ADDR reg adr
80 move.l #(((0xc000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
81.endm
82
83
84# make VDP word from address adr and store in d0
85.macro XRAM_ADDR_var adr
570c4371 86 move.l \adr,d0
0fc4f06b 87 lsl.l #8,d0
88 lsl.l #8,d0
89 rol.l #2,d0
90 lsl.b #2,d0
91 lsr.l #2,d0
4db6e09f 92.endm
93
94
0fc4f06b 95.macro VRAM_ADDR_var adr
96 XRAM_ADDR_var \adr
97 or.l #0x40000000,d0
4db6e09f 98.endm
99
100
0fc4f06b 101.macro CRAM_ADDR_var adr
102 XRAM_ADDR_var \adr
103 or.l #0xc0000000,d0
4db6e09f 104.endm
105
106
107.macro VSCROLL_ADDR reg adr
108 move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + ((\adr >> 14) | 0x10)),\reg
109.endm
110
111
112.macro HSCROLL_ADDR reg adr
113 move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
114.endm
115
116
1286a1ba 117# convert tile coords in d0, d1 to nametable addr to a0
118.macro XY2NT
119 lsl.w #6,d1
120 add.w d1,d0
121 lsl.w #1,d0
122 movea.l #0xe000,a0
123 add.w d0,a0
124.endm
125
4276cd7a 126# check if some d-pad button (and modifier) is pressed
fbad1b76 127.macro do_dpad bit op val
128 btst.l #\bit,d0
129 beq 0f
130 \op.l \val,a6
131 bra dpad_end
4276cd7a 1320:
4276cd7a 133.endm
134
4dfddc2f 135# convert a6 to normal addr
136# destroys d0
137.macro mk_a6_addr reg
138 move.l a6,\reg
139 moveq.l #0,d0
140 move.b \reg,d0
141 lsr.l #8,\reg
142 add.l d0,\reg
143.endm
144
145.macro change_mode mode_new mode_back
146 and.w #0xc0ff,d7
147 or.w #(\mode_back<<11)|(\mode_new<<8),d7
148.endm
149
27d5cc88 150.macro menu_text str x y pal
151 lea \str,a0
152 move.l #\x,d0
153 move.l #\y,d1
154 move.l #0x8000|(\pal<<13),d2
155 jsr print
156.endm
157
4db6e09f 158#################################################
159# #
160# DATA #
161# #
162#################################################
163
164colors:
4276cd7a 165 dc.w 0x0000,0x0eee,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
166 dc.w 0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
167 dc.w 0x0000,0x02e2,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
168 dc.w 0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
169 dc.w 0x0000,0x0e44,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
170 dc.w 0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
570c4371 171colors_end:
172
4db6e09f 173
174sprite_data:
175 /* Y size link attr X */
570c4371 176 dc.w 0; dc.b 0x05; dc.b 0; dc.w 0x6002; dc.w 0
4db6e09f 177sprite_data_end:
178
27d5cc88 179predef_addrs:
180 dc.l 0x000000, 0x200000, 0x400000, 0xa00000, 0xa10000
181 dc.l 0xa11100, 0xa12000, 0xa13000, 0xc00000
182predef_addrs_end:
183
184safe_addrs:
185 dc.l 0x000000, 0x7fffff
186 dc.l 0xe00000, 0xffffff
187 dc.l 0xa00000, 0xa163ff /* FIXME */
188 /* TODO: VDP */
189safe_addrs_end:
190
4dfddc2f 191txt_edit:
192 .ascii "- edit -\0"
193txt_a_confirm:
194 .ascii "A-confirm\0"
27d5cc88 195txt_about:
196 .ascii "hexed r1\0"
197txt_goto:
198 .ascii "Go to address\0"
199txt_goto_predef:
200 .ascii "Go to (predef)\0"
201txt_dtack:
202 .ascii "DTACK safety\0"
4dfddc2f 203
4db6e09f 204##################################################
205# #
206# MAIN PROGRAM #
207# #
208##################################################
27d5cc88 209
210# global regs:
211# a6 = page_start[31:8]|cursor_offs[7:0]
212# d7 = old_inputs[31:16]|edit_bytes[15:14]|g_mode_old[13:11]|g_mode[10:8]|irq_cnt[7:0]
213# d6 = edit_word_save[31:15]|edit_done[7]|no_dtack_detect[4]|autorep_cnt[3:0]
214# d5 = main: tmp
215# edit: edit_word[31:8]|edit_pos[4:2]|byte_cnt[1:0]
216# menu: sel
217
570c4371 218.align 2
219
4db6e09f 220main:
4276cd7a 221 /* mask irqs during init */
1286a1ba 222 move.w #0x2700,sr
223
27d5cc88 224.if 0
225 /* copy */
226 lea (0,pc),a0
227 move.l a0,d0
228 swap d0
229 lsr.l #4,d0
230 and.b #0x0f,d0
231 cmp.b #0,d0
232 bne 0f
233
234 move.w #8000/2,d0
235 move.l #0,a0
236 move.l #0x400000,a1
2371:
238 move.w (a0)+,(a1)+
239 dbra d0,1b
2400:
241.endif
242
1286a1ba 243 movea.l #0,a6
4dfddc2f 244 move.l #0x8000,d7
fbad1b76 245 moveq.l #0,d6
1286a1ba 246
247 /* Init pads */
248 move.b #0x40,(0xa10009).l
249 move.b #0x40,(0xa10003).l
250
4db6e09f 251 /* Initialize VDP */
252 jsr init_gfx
253
254 /* Load color data */
0fc4f06b 255 movea.l #0,a0
256 movea.l #colors,a1
257 moveq.l #(colors_end-colors)/2,d0
4db6e09f 258 jsr load_colors
259
260 /* load patterns */
0fc4f06b 261 movea.l #0,a0
262 movea.l #font,a1
263 move.l #128,d0
4db6e09f 264 jsr load_tiles
265
266 /* generate A layer map */
1286a1ba 267 movea.l #0xe000,a1
4db6e09f 268 move.l #28-1,d4
269lmaploop0:
1286a1ba 270 movea.l a1,a0
4db6e09f 271 jsr load_prepare
272
570c4371 273 move.l #64/2-1,d3
0fc4f06b 2740: move.l #0x00000000,(a0)
4db6e09f 275 dbra d3,0b
276
1286a1ba 277 add.l #64*2,a1
4db6e09f 278 dbra d4,lmaploop0
279
280 /* generate B layer map */
0fc4f06b 281 movea.l #0xc000,a0
4db6e09f 282 jsr load_prepare
283
570c4371 284 move.l #64*28/2-1,d3
0fc4f06b 2850: move.l #0x00000000,(a0)
4db6e09f 286 dbra d3,0b
287
288 /* upload sprite data */
0fc4f06b 289 movea.l #0xfc00,a0
4db6e09f 290 jsr load_prepare
0fc4f06b 291 movea.l #sprite_data,a1
4db6e09f 292
293 move.l #(sprite_data_end-sprite_data)/2-1,d3
0fc4f06b 2940: move.l (a1)+,(a0)
4db6e09f 295 dbra d3,0b
296
1286a1ba 297 move.w #0x2000,sr
570c4371 298
4db6e09f 299##################################################
1286a1ba 300
4db6e09f 301forever:
4db6e09f 302 jsr wait_vsync
303 bra forever
4db6e09f 304
305
1286a1ba 306VBL:
fbad1b76 307 addq.b #1,d7
5f6473d9 308 movem.l d0-d4/a0-a5,-(a7)
1286a1ba 309
fbad1b76 310 moveq.l #0,d0
311 move.w d7,d0
312 lsr.w #6,d0
313 and.w #0x1c,d0
314 move.l (jumptab,pc,d0),a0
315 jmp (a0)
316jumptab:
317 dc.l mode_main
4dfddc2f 318 dc.l mode_val_input
319 dc.l mode_edit_val /* edit val in editor */
320 dc.l mode_goto
27d5cc88 321 dc.l mode_start_menu
322 dc.l mode_goto_predef
fbad1b76 323 dc.l mode_main
324 dc.l mode_main
325
326##################### main #######################
327
328mode_main:
4276cd7a 329 clr.l d1
1286a1ba 330 move.l a6,d0
4276cd7a 331 move.b d0,d1
1286a1ba 332 lsr.l #8,d0
333 move.l d0,a1 /* current addr */
4276cd7a 334 lsr.b #3,d1
335 neg.b d1
336 add.b #27-1,d1 /* line where the cursor sits */
337 swap d1
1286a1ba 338
27d5cc88 339 movea.l #0xe002,a2
4276cd7a 340 move.l #27-1,d5 /* line counter for dbra */
341 or.l d1,d5
1286a1ba 342
27d5cc88 343draw_row:
1286a1ba 344 move.l a2,a0
345 jsr load_prepare
346
27d5cc88 347 btst.l #15,d7
348 beq 0f
349 move.w #' ',(a0)
3500:
1286a1ba 351 /* addr */
352 move.l a1,d2
353 moveq.l #6,d3
354 jsr print_hex_preped
355
27d5cc88 356 btst.l #4,d6
357 bne draw_row_safe
358
359 bsr is_addr_safe
360 bne draw_row_safe
361
362# draw unreadable areas
363 btst.l #15,d7
364 bne draw_row_unsafe_words
365
366draw_row_unsafe_bytes:
367 /* 8 bytes */
368 moveq.l #8-1,d4
3690:
370 move.w #' ',(a0)
371 move.l #'?'|('?'<<16),(a0)
372 dbra d4,0b
373
374 move.w #' ',(a0)
375
376 move.l d5,d0
377 swap d0
378 cmp.w d5,d0
379 beq draw_cursor_unsafe_byte
380 bra draw_chars_unsafe
381
382draw_row_unsafe_words:
383 /* 4 shorts */
384 moveq.l #4-1,d4
3850:
386 move.w #' ',(a0)
387 move.l #'?'|('?'<<16),(a0)
388 move.l #'?'|('?'<<16),(a0)
389 dbra d4,0b
390
391 move.l #(' '<<16)|' ',(a0)
392
393 move.l d5,d0
394 swap d0
395 cmp.w d5,d0
396 beq draw_cursor_unsafe_word
397
398draw_chars_unsafe:
399 move.l #'?'|('?'<<16),(a0)
400 move.l #'?'|('?'<<16),(a0)
401 move.l #'?'|('?'<<16),(a0)
402 move.l #'?'|('?'<<16),(a0)
403
404 move.l #(' '<<16)|' ',(a0)
405 addq.l #8,a1
406 add.w #0x80,a2
407 dbra d5,draw_row
408 bra draw_status_bar
409
410
411# normal draw
412draw_row_safe:
413 btst.l #15,d7
414 bne draw_row_words
415
416draw_row_bytes:
417 /* 8 bytes */
418 moveq.l #2,d3
419 moveq.l #8-1,d4
420draw_bytes:
421 move.w #' ',(a0)
422 move.b (a1)+,d2
423 jsr print_hex_preped
424 dbra d4,draw_bytes
425
426 move.w #' ',(a0)
427
428 move.l d5,d0
429 swap d0
430 cmp.w d5,d0
431 beq draw_cursor_byte
432 bra draw_chars_pre
433
434draw_row_words:
1286a1ba 435 /* 4 shorts */
4276cd7a 436 moveq.l #4,d3
1286a1ba 437 moveq.l #4-1,d4
27d5cc88 438draw_words:
1286a1ba 439 move.w #' ',(a0)
440 move.w (a1)+,d2
1286a1ba 441 jsr print_hex_preped
27d5cc88 442 dbra d4,draw_words
443
444 move.l #(' '<<16)|' ',(a0)
1286a1ba 445
4276cd7a 446 move.l d5,d0
447 swap d0
448 cmp.w d5,d0
27d5cc88 449 beq draw_cursor_word
4276cd7a 450
451draw_chars_pre:
1286a1ba 452 /* 8 chars */
453 subq.l #8,a1
454 moveq.l #8-1,d4
455draw_chars:
456 move.b (a1)+,d0
457 move.b d0,d1
458 sub.b #0x20,d1
459 cmp.b #0x60,d1
460 blo 0f
461 move.w #'.',d0
4620:
463 move.w d0,(a0)
464 dbra d4,draw_chars
465
27d5cc88 466 move.l #(' '<<16)|' ',(a0)
467
1286a1ba 468 add.w #0x80,a2
27d5cc88 469 dbra d5,draw_row
1286a1ba 470
27d5cc88 471draw_status_bar:
4276cd7a 472 /* status bar */
27d5cc88 473 move.l a2,a0
4276cd7a 474 jsr load_prepare
27d5cc88 475
476 btst.l #15,d7
477 beq 0f
478 move.w #' ',(a0)
4790:
4dfddc2f 480 mk_a6_addr d2
4276cd7a 481 move.l #0x4006,d3
482 jsr print_hex_preped
27d5cc88 483 move.w #' ',(a0)
4276cd7a 484
1286a1ba 485 /* handle input */
486 jsr get_input /* x0cbrldu x1sa00du */
1286a1ba 487
fbad1b76 488 btst.l #16+4,d0 /* A - scroll modifier */
489 beq input_noa
490
491 do_dpad 16+0, sub, #0x0800
492 do_dpad 16+1, add, #0x0800
493 do_dpad 16+10, sub, #0xd800
494 do_dpad 16+11, add, #0xd800
495input_noa:
496 moveq.l #0,d1
4dfddc2f 497 move.w d7,d1
498 lsr.w #7,d1
499 lsr.w #7,d1
fbad1b76 500
501 do_dpad 0, subq, #0x0008
502 do_dpad 1, addq, #0x0008
503 do_dpad 10, sub, d1
504 do_dpad 11, add, d1
505
506dpad_end:
4dfddc2f 507 /* update addr */
508 move.l a6,d1
509 cmp.b #0xf0,d1
510 blo 0f
511 sub.l #0xd800,a6
512 add.w #0x00d8,a6
513 bra 1f
5140:
515 cmp.b #0xd8,d1
516 blo 1f
517 add.l #0xd800,a6
518 sub.w #0x00d8,a6
5191:
520
521 /* other btns */
fbad1b76 522 moveq.l #0,d1
523 btst.l #12,d0 /* B - switch byte/word mode */
524 beq input_nob
4dfddc2f 525 bclr.l #15,d7
526 add.w #0x4000,d7 /* changes between 01 10 */
fbad1b76 527 move.l a6,d1
528 and.l #1,d1
529 sub.l d1,a6 /* make even, just in case */
530
531input_nob:
532 btst.l #13,d0 /* C - edit selected byte */
533 beq input_noc
4dfddc2f 534
535 change_mode MMODE_EDIT_VAL, MMODE_MAIN
27d5cc88 536 write_vdp_r_dst 12,(VDP12_SCREEN_V224 | VDP12_SCREEN_H320 | VDP12_STE),(GFXCNTL)
fbad1b76 537
538input_noc:
27d5cc88 539 btst.l #5,d0 /* Start - menu */
4dfddc2f 540 beq input_nos
541
27d5cc88 542 moveq.l #0,d5
543 change_mode MMODE_START_MENU, MMODE_MAIN
544 write_vdp_r_dst 12,(VDP12_SCREEN_V224 | VDP12_SCREEN_H320 | VDP12_STE),(GFXCNTL)
1286a1ba 545
4dfddc2f 546input_nos:
fbad1b76 547vbl_end:
5f6473d9 548 movem.l (a7)+,d0-d4/a0-a5
1286a1ba 549 rte
550
551
27d5cc88 552draw_cursor_unsafe_byte:
553 move.l a6,d0
554 and.l #7,d0 /* byte offs */
555 move.b d0,d1
556 add.b d0,d0
557 add.b d1,d0 /* d0 *= 3 (chars) */
558 add.b d0,d0
559 lea (7*2,a2,d0),a0
560 jsr load_prepare
561 move.l #(0x2000|'?'|((0x2000|'?')<<16)),(a0)
562
563 move.l a2,a0
564 add.w #31*2,a0
565 jsr load_prepare /* restore a0 */
566 jmp draw_chars_unsafe
567
568draw_cursor_unsafe_word:
4276cd7a 569 move.l a6,d0
570 and.l #7,d0 /* byte offs */
571 move.l d0,d1
572 lsr.b #1,d1 /* which word */
573 move.b d1,d2
574 lsl.b #2,d2
575 add.b d2,d1 /* num of chars to skip */
27d5cc88 576 add.b d1,d1
577
578 lea (8*2,a2,d1),a0
579 jsr load_prepare
580 move.l #(0x2000|'?'|((0x2000|'?')<<16)),d0
581 move.l d0,(a0)
582 move.l d0,(a0)
583
584 move.l a2,a0
585 add.w #29*2,a0
586 jsr load_prepare /* restore a0 */
587 jmp draw_chars_unsafe
4276cd7a 588
4276cd7a 589
fbad1b76 590draw_cursor_byte:
27d5cc88 591 move.l a6,d0
592 and.l #7,d0 /* byte offs */
593 move.w #0x2002,d3
594
fbad1b76 595 move.b (-8,a1,d0),d2
27d5cc88 596 move.b d0,d1
597 add.b d0,d0
598 add.b d1,d0 /* d0 *= 3 (chars) */
599 add.b d0,d0
600 lea (7*2,a2,d0),a0
601 jsr load_prepare
602 jsr print_hex_preped
603
604 move.l a2,a0
605 add.w #31*2,a0
606 jsr load_prepare /* restore a0 */
607
608 jmp draw_chars_pre
fbad1b76 609
610draw_cursor_word:
27d5cc88 611 move.l a6,d0
612 and.l #7,d0 /* byte offs */
613 move.l d0,d1
614 lsr.b #1,d1 /* which word */
615 move.b d1,d2
616 lsl.b #2,d2
617 add.b d2,d1 /* num of chars to skip */
618 add.b d1,d1
619 move.w #0x2004,d3
620
fbad1b76 621 move.w (-8,a1,d0),d2
27d5cc88 622 lea (8*2,a2,d1),a0
4276cd7a 623 jsr load_prepare
4276cd7a 624 jsr print_hex_preped
625
626 move.l a2,a0
27d5cc88 627 add.w #29*2,a0
4276cd7a 628 jsr load_prepare /* restore a0 */
629
630 jmp draw_chars_pre
631
632
4dfddc2f 633#################### hedit #######################
634
635mode_edit_val:
636 btst.l #7,d6
637 bne mode_hedit_finish
638
639 /* read val to edit */
5f6473d9 640 moveq.l #0,d5
4dfddc2f 641 mk_a6_addr d1
642 move.l d1,a0
4dfddc2f 643 btst.l #15,d7
644 bne 0f
5f6473d9 645 move.b (a0),d5
646 lsl.l #8,d5
647 or.b #1,d5
4dfddc2f 648 bra 1f
6490:
5f6473d9 650 move.w (a0),d5
651 lsl.l #8,d5
652 or.b #2,d5
4dfddc2f 6531:
4dfddc2f 654
4dfddc2f 655 change_mode MMODE_VAL_INPUT, MMODE_EDIT_VAL
656 jmp vbl_end
657
658mode_hedit_finish:
659 /* write the val */
660 mk_a6_addr d1
661 move.l d1,a0
5f6473d9 662 lsr.l #8,d5
4dfddc2f 663
664 btst.l #15,d7
665 bne 0f
5f6473d9 666 move.b d5,(a0)
4dfddc2f 667 bra 1f
6680:
5f6473d9 669 move.w d5,(a0)
4dfddc2f 6701:
671
4dfddc2f 672 bra return_to_main
673
674##################### goto #######################
675
676mode_goto:
677 btst.l #7,d6
678 bne mode_goto_finish
fbad1b76 679
5f6473d9 680 moveq.l #0,d5
681 swap d6
682 move.w d6,d5
683 swap d6
684 swap d5
685 or.b #3,d5 /* 3 bytes */
4dfddc2f 686 bclr.l #7,d6
687 change_mode MMODE_VAL_INPUT, MMODE_GOTO
688 jmp vbl_end
689
690mode_goto_finish:
5f6473d9 691 lsr.l #8,d5
692 move.l d5,d0
4dfddc2f 693 move.l d0,d1
694 and.l #7,d1
695 and.b #0xf8,d0
696 lsl.l #8,d0
697 or.l d1,d0
698 move.l d0,a6
699
5f6473d9 700 lsr.l #8,d5
701 swap d6
702 move.w d5,d6
703 swap d6
704
4dfddc2f 705 bra return_to_main
706
707################### val edit #####################
708
709mode_val_input:
710 /* frame */
711 movea.l #0xe000+14*2+11*64*2,a1
712 moveq.l #6-1,d1
7130:
714 move.w a1,a0
715 jsr load_prepare
716 moveq.l #11-1,d0
7171:
718 move.w #0,(a0)
719 dbra d0,1b
720
721 add.w #64*2,a1
722 dbra d1,0b
723
724 /* text */
725 lea txt_edit,a0
726 move.l #15,d0
727 move.l #11,d1
728 move.l #0xc000,d2
729 jsr print
730
731 lea txt_a_confirm,a0
732 move.l #15,d0
733 move.l #15,d1
734 move.l #0xc000,d2
735 jsr print
736
737 /* edit field */
738 moveq.l #0,d0
739 moveq.l #0,d1
740 moveq.l #0,d3
5f6473d9 741 move.b d5,d3
742 and.b #3,d3 /* edit field bytes */
4dfddc2f 743
744 move.b #19,d0
745 sub.b d3,d0
746 move.b #13,d1
5f6473d9 747 move.l d5,d2
4dfddc2f 748 lsr.l #8,d2
749 add.b d3,d3
750 or.w #0x8000,d3
751 jsr print_hex
752
753 /* current char */
754 moveq.l #0,d0
755 moveq.l #0,d1
756
757 and.w #6,d3
758 move.b #19,d0
759 move.b d3,d1
760 lsr.b #1,d1 /* length in bytes */
761 sub.b d1,d0
5f6473d9 762 move.b d5,d1
763 lsr.b #2,d1
4dfddc2f 764 and.b #7,d1 /* nibble to edit */
765 add.b d1,d0
766
767 sub.b d1,d3
768 sub.b #1,d3 /* chars to shift out */
769 lsl.b #2,d3
770 add.b #8,d3
5f6473d9 771 move.l d5,d2
4dfddc2f 772 lsr.l d3,d2
773
774 move.b #13,d1
775 move.w #0xa001,d3
776 jsr print_hex
777
778 /* handle input */
779 jsr get_input /* x0cbrldu x1sa00du */
780
781 move.w d0,d1
782 and.w #0x0f00,d1
783 beq ai_no_dpad
5f6473d9 784 move.b d5,d1
785 and.b #3,d1
4dfddc2f 786 add.b d1,d1 /* nibble count */
787 sub.b #1,d1 /* max n.t.e. val */
5f6473d9 788 move.b d5,d2
789 lsr.b #2,d2
4dfddc2f 790 and.b #7,d2 /* nibble to edit */
791
792 move.b d0,d3
793 and.b #3,d3
794 beq ai_no_ud
795 moveq.l #0,d3
796 moveq.l #0,d4
797 move.b #0xf,d3
798 move.b #0x1,d4
799 sub.b d2,d1
800 lsl.b #2,d1
801 add.b #8,d1
802 lsl.l d1,d3 /* mask */
803 lsl.l d1,d4 /* what to add/sub */
5f6473d9 804 move.l d5,d1
4dfddc2f 805 and.l d3,d1
806 btst.l #8,d0
807 beq 0f
808 add.l d4,d1
809 bra 1f
8100:
811 sub.l d4,d1
8121:
813 and.l d3,d1
814 eor.l #0xffffffff,d3
5f6473d9 815 and.l d3,d5
816 or.l d1,d5
4dfddc2f 817 jmp vbl_end
818
819ai_no_ud:
820 btst.l #10,d0
821 bne 0f
822 add.b #1,d2
823 bra 1f
8240:
825 sub.b #1,d2
8261:
827 cmp.b #0,d2
828 bge 0f
829 move.b d1,d2
8300:
831 cmp.b d1,d2
832 ble 0f
833 move.b #0,d2
8340:
5f6473d9 835 and.b #0xe3,d5
836 lsl.b #2,d2
837 or.b d2,d5
4dfddc2f 838 jmp vbl_end
839
840ai_no_dpad:
841 move.w d0,d1
842 and.w #0x1020,d1
843 beq ai_no_sb
844
4dfddc2f 845 bra return_to_main
846
847ai_no_sb:
5f6473d9 848 btst.l #4,d0 /* A - confirm */
4dfddc2f 849 beq ai_no_input
850 bset.l #7,d6
5f6473d9 851 move.w d7,d1 /* back to prev mode */
4dfddc2f 852 and.w #0x3800,d1
853 lsr.w #3,d1
854 and.w #0xc0ff,d7
855 or.w d1,d7
856
857ai_no_input:
858 jmp vbl_end
859
860
27d5cc88 861################### start menu ###################
862
863mode_start_menu:
864 /* frame */
865 bsr start_menu_box
866
867 /* text */
868 menu_text txt_about, 13, 9, 1
869 menu_text txt_goto, 13, 11, 0
870 menu_text txt_goto_predef, 13, 12, 0
871 menu_text txt_dtack, 13, 13, 0
872 menu_text txt_a_confirm, 13, 15, 2
873
874 /* dtack safety on/off */
875 movea.l #0xe000+26*2+13*64*2,a0
876 jsr load_prepare
877 move.w #0x8000|'O',(a0)
878 btst.l #4,d6
879 bne 0f
880 move.w #0x8000|'N',(a0)
881 bra 1f
8820:
883 move.w #0x8000|'F',(a0)
884 move.w #0x8000|'F',(a0)
8851:
886
887 /* cursor */
888 movea.l #0xe000+11*2+11*64*2,a0
889 moveq.l #0,d0
890 move.b d5,d0
891 and.b #3,d0
892 lsl.w #7,d0
893 add.w d0,a0
894 jsr load_prepare
895 move.w #'>',(a0)
896
897 /* input */
898 jsr get_input /* x0cbrldu x1sa00du */
899
900 move.w d0,d1
901 and.w #3,d1
902 beq msm_no_ud
903 move.b d5,d1
904 and.b #3,d1
905 btst.l #0,d0
906 sne d2
907 or.b #1,d2 /* up -1, down 1 */
908 add.b d2,d1
909 cmp.b #0,d1
910 bge 0f
911 move.b #2,d1
9120:
913 cmp.b #2,d1
914 ble 0f
915 move.b #0,d1
9160:
917 and.b #0xfc,d5
918 or.b d1,d5
919 jmp vbl_end
920
921msm_no_ud:
922 btst.l #4,d0 /* A - confirm */
923 beq msm_no_a
924 move.b d5,d1
925 and.b #3,d1
926 bne 0f
927 change_mode MMODE_GOTO, MMODE_MAIN
928 bsr start_menu_box
929 jmp vbl_end
9300:
931 cmp.b #1,d1
932 bne 0f
933 moveq.l #0,d5
934 change_mode MMODE_GOTO_PREDEF, MMODE_MAIN
935 bsr start_menu_box
936 jmp vbl_end
9370:
938 cmp.b #2,d1
939 bne 0f
940 bchg.l #4,d6
941 jmp vbl_end
9420:
943
944msm_no_a:
945 move.w d0,d1
946 and.w #0x3000,d1
947 beq msm_no_bc
948 bra return_to_main
949
950msm_no_bc:
951 jmp vbl_end
952
953start_menu_box:
954 movea.l #0xe000+10*2+8*64*2,a1
955 move.w #9-1,d1
9560:
957 move.w a1,a0
958 jsr load_prepare
959 move.w #20-1,d0
9601:
961 move.w #0,(a0)
962 dbra d0,1b
963
964 add.w #64*2,a1
965 dbra d1,0b
966 rts
967
968################### goto predef ##################
969
970mode_goto_predef:
971 /* frame */
972 movea.l #0xe000+14*2+8*64*2,a1
973 move.l #predef_addr_cnt+2-1,d1
9740:
975 move.w a1,a0
976 jsr load_prepare
977 moveq.l #10-1,d0
9781:
979 move.w #0,(a0)
980 dbra d0,1b
981
982 add.w #64*2,a1
983 dbra d1,0b
984
985 /* draw addresses */
986 movea.l #0xe000+17*2+9*64*2,a1
987 lea predef_addrs,a2
988 move.w #predef_addr_cnt-1,d4
989 move.l #0x8006,d3
990mgp_da_loop:
991 move.w a1,a0
992 jsr load_prepare
993 move.l (a2)+,d2
994 jsr print_hex_preped
995 add.w #64*2,a1
996 dbra d4,mgp_da_loop
997
998 /* cursor */
999 movea.l #0xe000+15*2+9*64*2,a0
1000 moveq.l #0,d0
1001 move.b d5,d0
1002 lsl.w #7,d0
1003 add.w d0,a0
1004 jsr load_prepare
1005 move.w #'>',(a0)
1006
1007 /* input */
1008 jsr get_input /* x0cbrldu x1sa00du */
1009
1010 move.w d0,d1
1011 and.w #3,d1
1012 beq mgp_no_ud
1013 btst.l #0,d0
1014 sne d2
1015 or.b #1,d2 /* up -1, down 1 */
1016 add.b d2,d5
1017 cmp.b #0,d5
1018 bge 0f
1019 move.b #predef_addr_cnt-1,d5
10200:
1021 cmp.b #predef_addr_cnt-1,d5
1022 ble 0f
1023 move.b #0,d5
10240:
1025 jmp vbl_end
1026
1027mgp_no_ud:
1028 btst.l #4,d0 /* A - confirm */
1029 beq mgp_no_a
1030 moveq.l #0,d0
1031 move.b d5,d0
1032 lsl.w #2,d0
1033 lea predef_addrs,a0
1034 move.l (a0,d0),d5
1035 lsl.l #8,d5
1036 jmp mode_goto_finish
1037
1038mgp_no_a:
1039 move.w d0,d1
1040 and.w #0x3000,d1
1041 beq mgp_no_bc
1042 bra return_to_main
1043
1044mgp_no_bc:
1045 jmp vbl_end
1046
1047
4dfddc2f 1048# go back to main mode
1049return_to_main:
5f6473d9 1050 bclr.l #7,d6 /* not edited */
4dfddc2f 1051 change_mode MMODE_MAIN, MMODE_MAIN
27d5cc88 1052 write_vdp_r_dst 12,(VDP12_SCREEN_V224 | VDP12_SCREEN_H320),(GFXCNTL)
fbad1b76 1053 jmp vbl_end
1054
1055
4db6e09f 1056#################################################
1057# #
1058# Initialize VDP registers #
1059# #
1060#################################################
1061
1062init_gfx:
1063 move.l #GFXCNTL,a3
570c4371 1064 write_vdp_reg 0,(VDP0_E_DISPLAY | VDP0_PLTT_FULL)
1065 write_vdp_reg 1,(VDP1_E_VBI | VDP1_E_DISPLAY | VDP1_E_DMA | VDP1_RESERVED)
4db6e09f 1066 write_vdp_reg 2,(0xe000 >> 10) /* Screen map a adress */
1067 write_vdp_reg 3,(0xe000 >> 10) /* Window address */
1068 write_vdp_reg 4,(0xc000 >> 13) /* Screen map b address */
1069 write_vdp_reg 5,(0xfc00 >> 9) /* Sprite address */
1070 write_vdp_reg 6,0
570c4371 1071 write_vdp_reg 7,0 /* Backdrop color */
4db6e09f 1072 write_vdp_reg 10,1 /* Lines per hblank interrupt */
1073 write_vdp_reg 11,0 /* 2-cell vertical scrolling */
570c4371 1074 write_vdp_reg 12,(VDP12_SCREEN_V224 | VDP12_SCREEN_H320)
1075 write_vdp_reg 13,(0x8000 >> 10) /* Horizontal scroll address */
4db6e09f 1076 write_vdp_reg 15,2
570c4371 1077 write_vdp_reg 16,(VDP16_MAP_V32 | VDP16_MAP_H64) /* layer size */
4db6e09f 1078 write_vdp_reg 17,0
1079 write_vdp_reg 18,0xff
1080 rts
1081
1082
27d5cc88 1083# determine if address packed in a6 is safe
1084# a1 - address to check
1085# destroys d0-d2, strips upper bits from a1
1086is_addr_safe:
1087 move.l a1,d1
1088 lsl.l #8,d1
1089 lsr.l #8,d1
1090 lea safe_addrs,a1
1091 move.w #(safe_addrs_end - safe_addrs)/8-1,d2
10920:
1093 move.l (a1)+,d0
1094 cmp.l d0,d1
1095 blt 1f
1096 move.l (a1),d0
1097 cmp.l d0,d1
1098 ble addr_safe
10991:
1100 addq.l #4,a1
1101 dbra d2,0b
1102
1103addr_unsafe:
1104 move.l d1,a1
1105 moveq.l #0,d0
1106 rts
1107
1108addr_safe:
1109 move.l d1,a1
1110 moveq.l #1,d0
1111 rts
1112
1113
1286a1ba 1114# read single phase from controller
fbad1b76 1115# #a0 - addr
1286a1ba 1116# d0 - result
fbad1b76 1117# destroys d1,d2
1286a1ba 1118get_input:
1119 move.b #0x40,(0xa10003)
1120 nop
1121 nop
1122 nop
1123 move.b (0xa10003),d0
1124 move.b #0x00,(0xa10003)
1125 lsl.w #8,d0
1126 nop
1127 move.b (0xa10003),d0
1128 eor.w #0xffff,d0
fbad1b76 1129
1130 swap d7
1131 move.w d7,d1
1132 eor.w d0,d1 /* changed btns */
1133 move.w d0,d7 /* old val */
1134 swap d7
1135 and.w d0,d1 /* what changed now */
1136 bne 0f
1137
1138 addq.b #1,d6
1139 move.b d6,d2
27d5cc88 1140 and.b #0x0f,d2 /* do autorepeat */
1141 cmp.b #9,d2
fbad1b76 1142 bne 1f
1143 move.w d0,d1
11440:
27d5cc88 1145 and.b #0xf0,d6
fbad1b76 11461:
1147 swap d0
1148 move.w d1,d0
1286a1ba 1149 rts
1150
0fc4f06b 1151# Load tile data from ROM
1152# a0: VRAM base
1153# a1: pattern address
1154# d0: number of tiles to load
1155# destroys d1
4db6e09f 1156
1157load_tiles:
0fc4f06b 1158 move.l d0,d1
1159 VRAM_ADDR_var a0
1160 move.l d0,(GFXCNTL).l
4db6e09f 1161
0fc4f06b 1162 move.l #GFXDATA,a0
1163 lsl.w #3,d1
1164 subq.l #1,d1
11650:
1166 move.l (a1)+,(a0)
1167 dbra d1,0b
4db6e09f 1168
1169 rts
1170
1171
4dfddc2f 1172# Prepare to write to VDP RAM @a0
0fc4f06b 1173# sets a0 to VDP data port for convenience
1174# a0: VRAM base
1175# destroys d0
570c4371 1176
4db6e09f 1177load_prepare:
0fc4f06b 1178 VRAM_ADDR_var a0
1179 move.l d0,(GFXCNTL).l
1180 move.l #GFXDATA,a0
4db6e09f 1181 rts
1182
1183
0fc4f06b 1184# Load color data from ROM
1185# a0: CRAM base
1186# a1: color list address
1187# d0: number of colors to load
1188# destroys d1
4db6e09f 1189
1190load_colors:
0fc4f06b 1191 move.l d0,d1
1192 CRAM_ADDR_var a0
1193 move.l d0,(GFXCNTL).l
4db6e09f 1194
0fc4f06b 1195 move.l #GFXDATA,a0
1196 subq.w #1,d1
11970:
1198 move.w (a1)+,(a0)
1199 dbra d1,0b
4db6e09f 1200
1201 rts
1202
0fc4f06b 1203
1204# print
1205# a0 - string
1206# d0 - x
1207# d1 - y
4dfddc2f 1208# d2 - tile_bits[15:11]
0fc4f06b 1209# destroys a1
570c4371 1210
1211print:
0fc4f06b 1212 move.l a0,a1
1286a1ba 1213 XY2NT
0fc4f06b 1214 jsr load_prepare
4dfddc2f 1215 move.l d2,d0
1216 and.w #0xf800,d0
570c4371 1217
1218_print_loop:
0fc4f06b 1219 move.b (a1)+,d0
570c4371 1220 beq _print_end
1221
0fc4f06b 1222 move.w d0,(a0)
570c4371 1223 jmp _print_loop
1224
1225_print_end:
1226 rts
1227
4db6e09f 1228
1286a1ba 1229# print_hex
1230# d0 - x
1231# d1 - y
1232# d2 - value
27d5cc88 1233# d3 - tile_bits[15:11]|digit_cnt[7:0]
4276cd7a 1234# destroys a0, preserves d3
1286a1ba 1235
1236print_hex:
1237 XY2NT
1238 jsr load_prepare
1239
1240print_hex_preped:
4276cd7a 1241 moveq.l #0,d0
1242 move.b d3,d0
1243 move.l d0,d1
1286a1ba 1244 lsl.b #2,d0
1245 ror.l d0,d2 /* prep value */
4276cd7a 1246 subq.l #1,d1 /* count */
1247 move.w d3,d0
1248 and.w #0xf800,d0 /* keep upper bits in d0 */
1286a1ba 1249
1250_print_hex_loop:
1251 rol.l #4,d2
1252 move.b d2,d0
1253 and.b #0xf,d0
1286a1ba 1254
1255 add.b #'0',d0
4276cd7a 1256 cmp.b #'9',d0
1257 ble 0f
1258 addq.b #7,d0
12590:
1286a1ba 1260 move.w d0,(a0)
4276cd7a 1261 dbra d1,_print_hex_loop
1286a1ba 1262
1263 rts
1264
1265
4db6e09f 1266#################################################
1267# #
1268# Wait for next VBlank interrupt #
1269# #
1270#################################################
1271
1272wait_vsync:
fbad1b76 1273 move.b d7,d0
4db6e09f 1274_wait_change:
1275 stop #0x2000
fbad1b76 1276 cmp.b d7,d0
4db6e09f 1277 beq _wait_change
1278 rts
1279
1280
1281#################################################
1282# #
1283# RAM DATA #
1284# #
1285#################################################
1286
1287.bss
570c4371 1288
fbad1b76 1289# nothing :)
4db6e09f 1290
1291.end
1292
1293# vim:filetype=asmM68k
Genesis/MegaDrive related projects