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r8971 Tuesday 31st August, 2010 at 10:52:11 UTC by Barry Rodewald
[PCW] Implemented serial transfer of keyboard input data from the keyboard MCU.
[src/mess/drivers]pcw.c

src/mess/drivers/pcw.c
r8970r8971
133133
134134static UINT16 pcw_kb_scan_row;
135135
136static UINT8* mcu_shared_ram;
136static UINT8 mcu_keyboard_data[16];
137static UINT8 mcu_transmit_reset_seq;
138static UINT8 mcu_transmit_count;
137139
138140static void pcw_update_interrupt_counter(void)
139141{
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227229ADDRESS_MAP_END
228230
229231
230/* Keyboard is read by the MCU and passed onto an area of RAM */
232/* Keyboard is read by the MCU and sent as serial data to the gate array ASIC */
231233static  READ8_HANDLER(pcw_keyboard_r)
232234{
233235   static const char *const keynames[] = {
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235237      "LINE8", "LINE9", "LINE10", "LINE11", "LINE12", "LINE13", "LINE14", "LINE15"
236238   };
237239
238   if(offset == 10)  // the MCU swaps the low 7 bits read from scan row 9, and places them in 0x3A.  This should fix any issue until we know just how the MCU transmits the RAM contents.
239      return (input_port_read(space->machine, keynames[offset]) & 0x80) | (input_port_read(space->machine, keynames[offset-1]) & 0x7f);
240240   return input_port_read(space->machine, keynames[offset]);
241241}
242242
243static READ8_HANDLER(pcw_mcu_shared_r)
243static READ8_HANDLER(pcw_keyboard_data_r)
244244{
245   return mcu_shared_ram[offset];
245   return mcu_keyboard_data[offset];
246246}
247247
248248/* -----------------------------------------------------------------------
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262262           handler */
263263      memory_install_read8_handler(space,
264264         block * 0x04000 + 0x3ff0, block * 0x04000 + 0x3fff, 0, 0,
265         pcw_mcu_shared_r);
265         pcw_keyboard_data_r);
266266//      LOG(("MEM: read block %i -> bank %i\n",block,bank));
267267   }
268268   else
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717717   return pcw_printer_command;
718718}
719719
720/*
721 *  Keyboard MCU (i8048)
722 *  P1 = keyboard scan row select (low 8 bits)
723 *  P2 = bits 7-4: keyboard scan row select (high 4 bits)
724 *       bit 1: keyboard serial clock
725 *       bit 0: keyboard serial data
726 */
727static void mcu_transmit_serial(UINT8 bit)
728{
729   static UINT8 selected;
730   static UINT8 buffer;
731   int seq;
732
733   /* Keyboard data is sent in serial from the MCU through the keyboard port, to the ASIC
734      Sends a string of 12-bit sequences, first 4 bits are the RAM location (from &3ff0),
735      then 8 bits for the data to be written there. */
736   logerror("KB: Transmitting bit #%i [%i]\n",mcu_transmit_count,bit);
737   seq = mcu_transmit_count % 12;
738   if(seq < 4)
739   {
740      if(bit == 0)
741         selected &= ~(8 >> seq);
742      else
743         selected |= (8 >> seq);
744   }
745   else
746   {
747      seq -= 4;
748      if(bit == 0)
749         buffer &= ~(128 >> seq);
750      else
751         buffer |= (128 >> seq);
752   }
753   mcu_transmit_count++;
754   if(mcu_transmit_count >= 12)
755   {
756      mcu_keyboard_data[selected] = buffer;
757      mcu_transmit_count = 0;
758      logerror("KB: Recieved data byte #%i [%02x]\n",selected,buffer);
759   }
760}
761
720762static READ8_HANDLER(mcu_kb_scan_r)
721763{
722764   return pcw_kb_scan_row & 0xff;
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734776
735777static WRITE8_HANDLER(mcu_kb_scan_high_w)
736778{
779   static UINT8 prev;
780
781   if((prev & 0x02) && !(data & 0x02))  // bit is transmitted on high-to-low clock transition
782   {
783      mcu_transmit_serial(data & 0x01);
784      mcu_transmit_reset_seq = 0;
785   }
786
787   if((prev & 0x01) != (data & 0x01))  // two high->low transitions on the data pin signals the beginning of a new transfer
788   {
789      mcu_transmit_reset_seq++;
790      if(mcu_transmit_reset_seq > 3)
791         mcu_transmit_count = 0;
792   }
793
737794   pcw_kb_scan_row = (pcw_kb_scan_row & 0x00ff) | ((data & 0xff) << 8);
795   prev = data;
738796}
739797
740798static READ8_HANDLER(mcu_kb_data_r)
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831889   AM_RANGE(MCS48_PORT_BUS, MCS48_PORT_BUS) AM_READ(mcu_kb_data_r)
832890ADDRESS_MAP_END
833891
834static ADDRESS_MAP_START(pcw_keyboard_data, ADDRESS_SPACE_DATA, 8)
835   AM_RANGE(0x30, 0x3f) AM_RAM AM_BASE(&mcu_shared_ram)
836ADDRESS_MAP_END
837892
838
839893static TIMER_CALLBACK(setup_beep)
840894{
841895   running_device *speaker = machine->device("beep");
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870924   pcw_boot = 0;   // System starts up in bootstrap mode, disabled until it's possible to emulate it.
871925
872926   /* copy boot code into RAM - yes, it's skipping a step */
873
874927   memset(messram_get_ptr(machine->device("messram")),0x00,messram_get_size(machine->device("messram")));
875928   for(x=0;x<256;x++)
876929      messram_get_ptr(machine->device("messram"))[x+2] = code[x+0x300];
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10451098   /* 2008-05  FP: not sure if this key is correct, "Caps Lock" is already mapped above.
10461099    For now, I let it with no default mapping. */
10471100   PORT_START("LINE13")   /* 0x03ffd */
1048   PORT_BIT(0x3f, 0xff, IPT_UNUSED)
1049   PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SHIFT LOCK") //PORT_CODE(KEYCODE_CAPSLOCK)
1050   PORT_BIT(0x80, 0xff, IPT_UNUSED)
1101   PORT_BIT(0xff, 0xff, IPT_UNUSED)
1102//   PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SHIFT LOCK") //PORT_CODE(KEYCODE_CAPSLOCK)
1103//   PORT_BIT(0x80, 0xff, IPT_UNUSED)
10511104
10521105   PORT_START("LINE14")   /* 0x03ffe */
10531106   PORT_BIT ( 0xff, 0xff,    IPT_UNUSED )
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11191172
11201173   MDRV_CPU_ADD("keyboard_mcu", I8048, 1000000) // clock is a guess for now
11211174   MDRV_CPU_IO_MAP(pcw_keyboard_io)
1122   MDRV_CPU_DATA_MAP(pcw_keyboard_data)
11231175
11241176   MDRV_I8243_ADD("printer_8243", NULL, pcw_printer_output_w)
11251177

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