1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
|
// license:BSD-3-Clause
// copyright-holders:Robbbert
/***************************************************************************
microbee.c
video hardware
Originally written by Juergen Buchmueller, Dec 1999
Rewritten by Robbbert (see notes in driver file).
Operation of old keyboard:
The design is taken from the SY6545 Application Note AN3. As the CRTC
renders the picture, the MA lines also scan the keyboard. When a keydown
is detected, the lightpen pin is activated, which sets bit 6 of the status
register. The CPU continuously monitors this register. Once bit 6 is set,
the CPU needs to determine which key is pressed. It firstly clears bit 6,
then sets port 0B to 1. This prevents the CRTC from scanning the keyboard
and causing interference. Next, the CPU writes an address to regs 18,19 and
then instigates the transparent access. This checks one keyboard row, which
if the pressed key is found, will once again set bit 6. If not found, the
next row will be checked. Once found, the CPU clears bit 6 and port 0B, then
works out the ascii key code of the pressed key.
Tests of old keyboard. Start mbeeic.
1. Load ASTEROIDS PLUS, stay in attract mode, hold down spacebar,
it should only fire bullets. If it sometimes starts turning,
thrusting or using the shield, then there is a problem.
2. Load SCAVENGER and make sure it doesn't go to the next level
until you find the Exit.
3. At the Basic prompt, type in EDASM press enter. At the memory size
prompt press enter. Now, make sure the keyboard works properly.
Old keyboard ToDo:
- Occasional characters dropped while typing
- Lots of characters dropped when pasting
- On mbee128p, Simply Write doesn't accept any input
New keyboard ToDo:
- On mbeett, various problems caused by phantom characters.
****************************************************************************/
#include "includes/mbee.h"
WRITE_LINE_MEMBER( mbee_state::crtc_vs )
{
m_b7_vs = state;
if ((m_io_config->read() & 0xc0) == 0) // VS selected in config menu
m_pio->port_b_write(pio_port_b_r(generic_space(),0,0xff));
}
/***********************************************************
The 6845 can produce a variety of cursor shapes - all
are emulated here.
Need to find out if the 6545 works the same way.
************************************************************/
void mbee_state::sy6545_cursor_configure()
{
UINT8 i,curs_type=0,r9,r10,r11;
/* curs_type holds the general cursor shape to be created
0 = no cursor
1 = partial cursor (only shows on a block of scan lines)
2 = full cursor
3 = two-part cursor (has a part at the top and bottom with the middle blank) */
for ( i = 0; i < ARRAY_LENGTH(m_sy6545_cursor); i++) m_sy6545_cursor[i] = 0; // prepare cursor by erasing old one
r9 = m_sy6545_reg[9]; // number of scan lines - 1
r10 = m_sy6545_reg[10] & 0x1f; // cursor start line = last 5 bits
r11 = m_sy6545_reg[11]+1; // cursor end line incremented to suit for-loops below
/* decide the curs_type by examining the registers */
if (r10 < r11) curs_type=1; // start less than end, show start to end
else
if (r10 == r11) curs_type=2; // if equal, show full cursor
else curs_type=3; // if start greater than end, it's a two-part cursor
if ((r11 - 1) > r9) curs_type=2; // if end greater than scan-lines, show full cursor
if (r10 > r9) curs_type=0; // if start greater than scan-lines, then no cursor
if (r11 > 16) r11=16; // truncate 5-bit register to fit our 4-bit hardware
/* create the new cursor */
if (curs_type > 1) for (i = 0;i < ARRAY_LENGTH(m_sy6545_cursor);i++) m_sy6545_cursor[i]=0xff; // turn on full cursor
if (curs_type == 1) for (i = r10;i < r11;i++) m_sy6545_cursor[i]=0xff; // for each line that should show, turn on that scan line
if (curs_type == 3) for (i = r11; i < r10;i++) m_sy6545_cursor[i]=0; // now take a bite out of the middle
}
/***********************************************************
Handlers of video, colour, and attribute RAM
************************************************************/
READ8_MEMBER( mbee_state::video_low_r )
{
if (m_is_premium && ((m_1c & 0x9f) == 0x90))
return m_p_attribram[offset];
else
if (m_0b)
return m_p_gfxram[offset];
else
return m_p_videoram[offset];
}
WRITE8_MEMBER( mbee_state::video_low_w )
{
if BIT(m_1c, 4)
{
// non-premium attribute writes are discarded
if (m_is_premium && BIT(m_1c, 7))
m_p_attribram[offset] = data;
}
else
m_p_videoram[offset] = data;
}
READ8_MEMBER( mbee_state::video_high_r )
{
if BIT(m_08, 6)
return m_p_colorram[offset];
else
return m_p_gfxram[(((m_1c & 15) + 1) << 11) | offset];
}
WRITE8_MEMBER( mbee_state::video_high_w )
{
if (BIT(m_08, 6) && (~m_0b & 1))
m_p_colorram[offset] = data;
else
m_p_gfxram[(((m_1c & 15) + 1) << 11) | offset] = data;
}
WRITE8_MEMBER( mbee_state::port0b_w )
{
m_0b = data & 1;
}
READ8_MEMBER( mbee_state::port08_r )
{
return m_08;
}
WRITE8_MEMBER( mbee_state::port08_w )
{
m_08 = data & 0x4e;
}
READ8_MEMBER( mbee_state::port1c_r )
{
return m_1c;
}
WRITE8_MEMBER( mbee_state::port1c_w )
{
/* d7 extended graphics (1=allow attributes and pcg banks)
d5 bankswitch basic rom
d4 select attribute ram
d3..d0 select m_videoram bank */
if (m_is_premium && BIT(data, 7))
m_1c = data;
else
m_1c = data & 0x30;
if (m_basic)
m_basic->set_entry(BIT(data, 5));
}
/***********************************************************
CRTC-driven keyboard
************************************************************/
void mbee_state::oldkb_matrix_r(UINT16 offs)
{
if (m_has_oldkb)
{
UINT8 port = (offs >> 7) & 7;
UINT8 bit = (offs >> 4) & 7;
UINT8 extra = 0;
UINT8 data = m_io_oldkb[port]->read();
bool keydown = BIT(data, bit);
// This adds premium-style cursor keys to the old keyboard.
// They are used by the pc85 menu. Premium keyboards already
// have these keys fitted.
if (!keydown && !m_is_premium)
{
if ((port == 0) || (port == 2) || (port == 3))
extra = m_io_x7->read();
else
if (port == 7)
extra = data;
if (extra)
{
if BIT(extra, 0) // cursor up
{
if( port == 7 && bit == 1 ) keydown = 1;
if( port == 0 && bit == 5 ) keydown = 1; // control E
}
else
if BIT(extra, 2) // cursor down
{
if( port == 7 && bit == 1 ) keydown = 1;
if( port == 3 && bit == 0 ) keydown = 1; // control X
}
else
if BIT(extra, 3) // cursor left
{
if( port == 7 && bit == 1 ) keydown = 1;
if( port == 2 && bit == 3 ) keydown = 1; // control S
}
else
if BIT(extra, 6) // cursor right
{
if( port == 7 && bit == 1 ) keydown = 1;
if( port == 0 && bit == 4 ) keydown = 1; // control D
}
}
}
if( keydown )
m_crtc->assert_light_pen_input(); //lpen_strobe
}
}
void mbee_state::oldkb_scan( UINT16 param )
{
if (m_0b) return; // IC5 (pins 11,12,13)
if (param & 15) return; // only scan once per row instead of 16 times
oldkb_matrix_r(param);
}
/***********************************************************
CRTC registers
************************************************************/
WRITE8_MEMBER ( mbee_state::m6545_index_w )
{
data &= 0x1f;
m_sy6545_ind = data;
m_crtc->address_w( space, 0, data );
}
WRITE8_MEMBER ( mbee_state::m6545_data_w )
{
static const UINT8 sy6545_mask[32]={0xff,0xff,0xff,0x0f,0x7f,0x1f,0x7f,0x7f,3,0x1f,0x7f,0x1f,0x3f,0xff,0x3f,0xff,0,0,0x3f,0xff};
switch( m_sy6545_ind )
{
case 12:
data &= 0x3f; // select alternate character set
if( m_sy6545_reg[12] != data )
memcpy(m_p_gfxram, memregion("gfx")->base() + (((data & 0x30) == 0x20) << 11), 0x800);
break;
}
m_sy6545_reg[m_sy6545_ind] = data & sy6545_mask[m_sy6545_ind]; /* save data in register */
m_crtc->register_w( space, 0, data );
if ((m_sy6545_ind > 8) && (m_sy6545_ind < 12)) sy6545_cursor_configure(); /* adjust cursor shape - remove when mame fixed */
}
/***********************************************************
Video
************************************************************/
VIDEO_START_MEMBER( mbee_state, mono )
{
m_p_videoram = memregion("videoram")->base();
m_p_gfxram = memregion("gfx")->base()+0x1000;
m_p_colorram = 0;
m_p_attribram = 0;
m_is_premium = 0;
}
VIDEO_START_MEMBER( mbee_state, standard )
{
m_p_videoram = memregion("videoram")->base();
m_p_gfxram = memregion("gfx")->base()+0x1000;
m_p_colorram = memregion("colorram")->base();
m_p_attribram = 0;
m_is_premium = 0;
}
VIDEO_START_MEMBER( mbee_state, premium )
{
m_p_videoram = memregion("videoram")->base();
m_p_colorram = memregion("colorram")->base();
m_p_gfxram = memregion("gfx")->base()+0x1000;
m_p_attribram = memregion("attrib")->base();
m_is_premium = 1;
}
UINT32 mbee_state::screen_update_mbee(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
{
m_framecnt++;
m_crtc->screen_update(screen, bitmap, cliprect);
return 0;
}
MC6845_ON_UPDATE_ADDR_CHANGED( mbee_state::crtc_update_addr )
{
// parameters passed are device, address, strobe(always 0)
// not used on 256TC
oldkb_matrix_r(address);
}
MC6845_UPDATE_ROW( mbee_state::crtc_update_row )
{
const rgb_t *palette = m_palette->palette()->entry_list_raw();
// colours
UINT8 colourm = (m_08 & 0x0e) >> 1;
UINT8 monopal = (m_io_config->read() & 0x30) >> 4;
// if colour chosen on mono bee, default to amber
if (!monopal && !m_p_colorram)
monopal = 2;
UINT32 *p = &bitmap.pix32(y);
UINT8 inv, attr=0, gfx, fg=96+monopal, bg=96, col=0;
UINT16 mem, x, chr;
for (x = 0; x < x_count; x++) // for each character
{
inv = 0;
mem = (ma + x) & 0x7ff;
chr = m_p_videoram[mem];
if BIT(m_1c, 7) // premium graphics enabled?
{
attr = m_p_attribram[mem];
if BIT(chr, 7)
chr += ((attr & 15) << 7); // bump chr to its particular pcg definition
if BIT(attr, 6)
inv ^= 0xff; // inverse attribute
if (BIT(attr, 7) & BIT(m_framecnt, 4)) // flashing attribute
chr = 0x20;
}
oldkb_scan(x+ma);
/* process cursor */
if (x == cursor_x)
inv ^= m_sy6545_cursor[ra]; // cursor scan row
/* get pattern of pixels for that character scanline */
gfx = m_p_gfxram[(chr<<4) | ra] ^ inv;
// get colours
if (!monopal)
{
col = m_p_colorram[mem]; // read a byte of colour
if (m_is_premium)
{
fg = col & 15;
bg = col >> 4;
}
else
{
fg = (col & 0x1f) | 64;
bg = ((col & 0xe0) >> 2) | colourm;
}
}
/* Display a scanline of a character (8 pixels) */
*p++ = palette[BIT(gfx, 7) ? fg : bg];
*p++ = palette[BIT(gfx, 6) ? fg : bg];
*p++ = palette[BIT(gfx, 5) ? fg : bg];
*p++ = palette[BIT(gfx, 4) ? fg : bg];
*p++ = palette[BIT(gfx, 3) ? fg : bg];
*p++ = palette[BIT(gfx, 2) ? fg : bg];
*p++ = palette[BIT(gfx, 1) ? fg : bg];
*p++ = palette[BIT(gfx, 0) ? fg : bg];
}
}
/*****************************************************************************************************
Palette
Standard Palette: The 8 bits from the colour RAM are divided into 5 bits for foreground, and 3
bits for background. The 5 foreground bits pass through a PAL, which has 6 outputs. A write to
port 8 produces 3 more background lines, giving 6 in total. These 12 lines travel to a pair of
74LS157 switching chips, where the foreground or background lines are selected by the absence or
or presence of a pixel. The 6 chosen lines pass through a 7407 then are merged to the final 3 RGB
lines. Each pair is merged like this:
VCC --- 330 ohm --- primary colour line + out to monitor ---- 120 ohm --- secondary colour line
*****************************************************************************************************/
PALETTE_INIT_MEMBER( mbee_state, standard )
{
const UINT8 *color_prom = memregion("proms")->base();
UINT8 i=0, r, b, g, k, r1, g1, b1;
UINT8 bglevel[] = { 0, 0x54, 0xa0, 0xff };
UINT8 fglevel[] = { 0, 0xa0, 0xff, 0xff };
// set up background colours (00-63)
for (b1 = 0; b1 < 4; b1++)
{
b = bglevel[b1];
for (g1 = 0; g1 < 4; g1++)
{
g = bglevel[g1];
for (r1 = 0; r1 < 4; r1++)
{
r = bglevel[r1];
k = BITSWAP8(i, 7, 6, 5, 3, 1, 4, 2, 0);
palette.set_pen_color(k, rgb_t(r, g, b));
i++;
}
}
}
// set up foreground palette (64-95) by reading the prom
for (i = 0; i < 32; i++)
{
k = color_prom[i];
r = fglevel[(BIT(k, 2))|(BIT(k, 5)<<1)];
g = fglevel[(BIT(k, 1))|(BIT(k, 4)<<1)];
b = fglevel[(BIT(k, 0))|(BIT(k, 3)<<1)];
palette.set_pen_color(i|64, rgb_t(r, g, b));
}
// monochrome palette
palette.set_pen_color(96, rgb_t(0x00, 0x00, 0x00)); // black
palette.set_pen_color(97, rgb_t(0x00, 0xff, 0x00)); // green
palette.set_pen_color(98, rgb_t(0xf7, 0xaa, 0x00)); // amber
palette.set_pen_color(99, rgb_t(0xff, 0xff, 0xff)); // white
}
PALETTE_INIT_MEMBER( mbee_state, premium )
{
UINT8 i, r, b, g;
/* set up 8 low intensity colours */
for (i = 0; i < 7; i++)
{
r = BIT(i, 0) ? 0xc0 : 0;
g = BIT(i, 1) ? 0xc0 : 0;
b = BIT(i, 2) ? 0xc0 : 0;
palette.set_pen_color(i, rgb_t(r, g, b));
}
// colour 8 is dark grey, rather than black
palette.set_pen_color(8, rgb_t(96, 96, 96));
/* set up 8 high intensity colours */
for (i = 9; i < 16; i++)
{
r = BIT(i, 0) ? 0xff : 0;
g = BIT(i, 1) ? 0xff : 0;
b = BIT(i, 2) ? 0xff : 0;
palette.set_pen_color(i, rgb_t(r, g, b));
}
// monochrome palette
palette.set_pen_color(96, rgb_t(0x00, 0x00, 0x00)); // black
palette.set_pen_color(97, rgb_t(0x00, 0xff, 0x00)); // green
palette.set_pen_color(98, rgb_t(0xf7, 0xaa, 0x00)); // amber
palette.set_pen_color(99, rgb_t(0xff, 0xff, 0xff)); // white
}
|