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r15738 Friday 3rd August, 2012 at 23:12:32 UTC by Jonathan Gevaryahu
SOCRATES: document that an MCU dump is missing of the 4-bit TMP42C40P that decodes the IR signal from the keyboard and buffers the 'second stage' of the keyboard input. Changed code slightly to reflect this. [Lord Nightmare, Balrog]
[src/mess/drivers]socrates.c

src/mess/drivers/socrates.c
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1212    add waitstates for ram access (lack of this causes the system to run way too fast)
1313    find and hook up any timers/interrupt controls
1414    switch cartridges over to a CART system rather than abusing BIOS
15    keyboard IR decoder MCU is HLE'd for now, needs decap and cpu core (it is rather tms1000 or CIC-like)
1516
1617
17
1818  Socrates Educational Video System
1919        FFFF|----------------|
2020            | RAM (window 1) |
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8080{
8181public:
8282   socrates_state(const machine_config &mconfig, device_type type, const char *tag)
83      : driver_device(mconfig, type, tag) { }
83      : driver_device(mconfig, type, tag),
84      m_maincpu(*this, "maincpu"),
85      m_screen(*this, "screen"),
86      m_sound(*this, "soc_snd")
87      { }
88   required_device<cpu_device> m_maincpu;
89   required_device<screen_device> m_screen;
90   required_device<device_t> m_sound;
8491
8592   rgb_t m_palette[256];
8693
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9299   UINT8 m_kb_latch_low[2];
93100   UINT8 m_kb_latch_high[2];
94101   UINT8 m_kb_latch_mouse;
102   UINT8 m_kbmcu_rscount; // how many pokes the kbmcu has taken in the last frame
95103   UINT8 m_io40_latch; // what was last written to speech reg (for open bus)?
96104   UINT8 m_hblankstate; // are we in hblank?
97105   UINT8 m_vblankstate; // are we in vblank?
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106114   DECLARE_READ8_MEMBER(socrates_ram_bank_r);
107115   DECLARE_WRITE8_MEMBER(socrates_ram_bank_w);
108116   DECLARE_READ8_MEMBER(read_f3);
109   DECLARE_WRITE8_MEMBER(unknownlatch_30);
117   DECLARE_WRITE8_MEMBER(kbmcu_strobe);
110118   DECLARE_READ8_MEMBER(status_and_speech);
111119   DECLARE_WRITE8_MEMBER(speech_command);
112120   DECLARE_READ8_MEMBER(socrates_keyboard_low_r);
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207215 state->m_kb_latch_low[1] = 0x00;
208216 state->m_kb_latch_high[1] = 0x01;
209217 state->m_kb_latch_mouse = 0;
218 state->m_kbmcu_rscount = 0;
210219 state->m_io40_latch = 0;
211220 state->m_hblankstate = 0;
212221 state->m_vblankstate = 0;
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231240
232241READ8_MEMBER(socrates_state::socrates_rom_bank_r)
233242{
234 UINT8 data = 0xFF;
235 data = m_rom_bank;
236 return data;
243 return m_rom_bank;
237244}
238245
239246WRITE8_MEMBER(socrates_state::socrates_rom_bank_w)
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244251
245252READ8_MEMBER(socrates_state::socrates_ram_bank_r)
246253{
247 UINT8 data = 0xFF;
248 data = m_ram_bank;
249 return data;
254 return m_ram_bank;
250255}
251256
252257WRITE8_MEMBER(socrates_state::socrates_ram_bank_w)
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260265 return 0xF3;
261266}
262267
263WRITE8_MEMBER(socrates_state::unknownlatch_30)// writes to i/o 0x3x do SOMETHING, possibly waitstate related (may halt cpu until vblank start?) or involve status reg bit 6
268WRITE8_MEMBER(socrates_state::kbmcu_strobe) // strobe the keyboard MCU
264269{
265//logerror("write to i/o 0x30, data %x\n", data); // too annoying to leave enabled
270   //logerror("0x%04X: kbmcu written with %02X!\n", cpu_get_pc(m_maincpu), data); //if (cpu_get_pc(m_maincpu) != 0x31D)
271   // if two writes happen within one frame, reset the keyboard latches
272   m_kbmcu_rscount++;
273   if (m_kbmcu_rscount > 1)
274   {
275      m_kb_latch_low[0] = 0x00;
276      m_kb_latch_high[0] = 0x01;
277      m_kb_latch_low[1] = 0x00;
278      m_kb_latch_high[1] = 0x01;
279      m_kb_latch_mouse = 0;
280   }
266281}
267282
268283READ8_MEMBER(socrates_state::status_and_speech)// read 0x4x, some sort of status reg
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279294UINT8 *speechromext = memregion("speechext")->base();
280295   int temp = 0;
281296   temp |= (m_speech_running)?0x80:0;
282   temp |= 0x40; // unknown
297   temp |= 0x40; // unknown, possibly IR mcu busy
283298   temp |= (m_vblankstate)?0:0x20;
284299   temp |= (m_hblankstate)?0:0x10;
285300   switch(m_io40_latch&0xF0) // what was last opcode sent?
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688703    0x21 - W - msb offset of screen display
689704    resulting screen line is one of 512 total offsets on 128-byte boundaries in the whole 64k ram
690705    */
691   AM_RANGE(0x30, 0x30) AM_READWRITE(read_f3, unknownlatch_30) AM_MIRROR (0xf) /* unknown, write only. may relate to waitstate timing? */
706   AM_RANGE(0x30, 0x30) AM_READWRITE(read_f3, kbmcu_strobe) AM_MIRROR (0xf) /* resets the keyboard IR decoder MCU */
692707   AM_RANGE(0x40, 0x40) AM_READWRITE(status_and_speech, speech_command ) AM_MIRROR(0xf) /* reads status register for vblank/hblank/speech, also reads and writes speech module */
693708   AM_RANGE(0x50, 0x50) AM_READWRITE(socrates_keyboard_low_r, socrates_keyboard_clear) AM_MIRROR(0xE) /* Keyboard keycode low, latched on keypress, can be unlatched by writing anything here */
694709   AM_RANGE(0x51, 0x51) AM_READWRITE(socrates_keyboard_high_r, socrates_keyboard_clear) AM_MIRROR(0xE) /* Keyboard keycode high, latched as above, unlatches same as above */
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900915   device->machine().scheduler().timer_set(downcast<cpu_device *>(device)->cycles_to_attotime(44), FUNC(clear_irq_cb));
901916// 44 is a complete and total guess, need to properly measure how many clocks/microseconds the int line is high for.
902917   state->m_vblankstate = 1;
918   state->m_kbmcu_rscount = 0; // clear the mcu poke count
903919}
904920
905921static MACHINE_CONFIG_START( socrates, socrates_state )
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9951011
9961012    ROM_REGION(0x10000, "vram", ROMREGION_ERASEFF) /* fill with ff, driver_init changes this to the 'correct' startup pattern */
9971013
1014    ROM_REGION(0x800, "kbmcu", ROMREGION_ERASEFF)
1015    ROM_LOAD("tmp42c40p1844.bin", 0x000, 0x200, NO_DUMP) /* keyboard IR decoder MCU */
1016
9981017    /* english speech cart has a green QC sticker */
9991018    ROM_REGION(0x2000, "speechint", ROMREGION_ERASE00) // speech data inside of the speech chip; fill with 00, if no speech cart is present socrates will see this
10001019    ROM_LOAD_OPTIONAL("speech_internal.bin", 0x0000, 0x2000, CRC(edc1fb3f) SHA1(78b4631fc3b1c038e14911047f9edd6c4e8bae58)) // 8k on the speech chip itself
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10141033
10151034    ROM_REGION(0x10000, "vram", ROMREGION_ERASEFF) /* fill with ff, driver_init changes this to the 'correct' startup pattern */
10161035
1036    ROM_REGION(0x800, "kbmcu", ROMREGION_ERASEFF)
1037    ROM_LOAD("tmp42c40p1844.bin", 0x000, 0x200, NO_DUMP) /* keyboard IR decoder MCU */
1038
10171039    ROM_REGION(0x2000, "speechint", ROMREGION_ERASE00) // speech data inside of the speech chip; fill with 00, if no speech cart is present socrates will see this
10181040    ROM_LOAD_OPTIONAL("speech_fra_internal.bin", 0x0000, 0x2000, BAD_DUMP CRC(edc1fb3f) SHA1(78b4631fc3b1c038e14911047f9edd6c4e8bae58)) // probably same on french and english speech carts
10191041

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