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r23749 Monday 17th June, 2013 at 12:01:51 UTC by Robbbert
(MESS) Alphatronic: Can load the user-supplied tape. Sometimes it can load its own tapes.
[src/mess/drivers]alphatro.c

trunk/src/mess/drivers/alphatro.c
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44
55    skeleton driver
66
7    z80 + HD46505 as a CRTC
7    z80 + HD46505SP as a CRTC
88
9        Has a socket for monochrome (to the standard amber monitor),
10        and another for RGB. We emulate this with a configuration switch.
9    Other chips: 8251, 8257, 8259
10    Crystals: 16MHz, 17.73447MHz
11    Floppy format: 2 sides, 40 tracks, 16 sectors, 256 bytes = 320kb.
12    FDC (unknown) is in a plug-in module.
1113
12        The Z80 must start at E000, but unlike other designs (Super80 for
13        example) which causes the ROMs to appear everywhere during boot,
14        this one (it seems) holds the data bus low until E000 is reached.
15        This kind of boot still needs to be emulated.
14    Has a socket for monochrome (to the standard amber monitor),
15    and another for RGB. We emulate this with a configuration switch.
1616
17        This machine has 64k RAM, the ROMs being copied into RAM when
18        needed.
17    The Z80 must start at E000, but unlike other designs (Super80 for
18    example) which cause the ROMs to appear everywhere during boot,
19    this one (it seems) holds the data bus low until E000 is reached.
20    This kind of boot still needs to be emulated.
1921
22    This machine has 64k RAM, the ROMs being copied into RAM when
23    needed.
24
2025***************************************************************************/
2126
2227#include "emu.h"
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4954   m_cass(*this, "cassette"),
5055   m_beep(*this, "beeper"),
5156   m_p_ram(*this, "p_ram"),
52   m_p_videoram(*this, "p_videoram"){ }
57   m_p_videoram(*this, "videoram"){ }
5358
5459   required_device<cpu_device> m_maincpu;
5560   required_device<mc6845_device> m_crtc;
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6267   DECLARE_INPUT_CHANGED_MEMBER(alphatro_break);
6368   DECLARE_READ_LINE_MEMBER(rxdata_callback);
6469   DECLARE_WRITE_LINE_MEMBER(txdata_callback);
70   TIMER_DEVICE_CALLBACK_MEMBER(alphatro_c);
71   TIMER_DEVICE_CALLBACK_MEMBER(alphatro_p);
6572
6673   required_shared_ptr<UINT8> m_p_ram;
6774   required_shared_ptr<UINT8> m_p_videoram;
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7582
7683private:
7784   UINT8 m_timer_bit;
85   UINT8 m_cass_data[4];
86   bool m_cass_state;
7887   virtual void palette_init();
7988};
8089
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105114   }
106115
107116   m_cass->change_state( BIT(data, 3) ? CASSETTE_MOTOR_ENABLED : CASSETTE_MOTOR_DISABLED, CASSETTE_MASK_MOTOR);
117
118   if (BIT(data,2))
119      m_cass_state = 1;
108120}
109121
110122void alphatro_state::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
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128140
129141READ_LINE_MEMBER( alphatro_state::rxdata_callback )
130142{
131   return (m_cass->input() > -0.1) ? 1 : 0;
143   return (bool)m_cass_data[2];
132144}
133145
134146WRITE_LINE_MEMBER( alphatro_state::txdata_callback )
135147{
136   m_cass->output( (state) ? 0.8 : -0.8);
148   m_cass_state = state;
137149}
138150
139151void alphatro_state::video_start()
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186198
187199static ADDRESS_MAP_START( alphatro_map, AS_PROGRAM, 8, alphatro_state )
188200   AM_RANGE(0x0000, 0xefff) AM_RAM AM_SHARE("p_ram")
189   AM_RANGE(0xf000, 0xffff) AM_RAM AM_SHARE("p_videoram")
201   AM_RANGE(0xf000, 0xffff) AM_RAM AM_SHARE("videoram")
190202ADDRESS_MAP_END
191203
192204static ADDRESS_MAP_START( alphatro_io, AS_IO, 8, alphatro_state )
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353365void alphatro_state::machine_reset()
354366{
355367   // do what the IPL does
356   //  UINT8* RAM = machine().device<ram_device>("ram")->pointer();
357368   UINT8* ROM = memregion("maincpu")->base();
358369   m_maincpu->set_pc(0xe000);
359370   memcpy(m_p_ram, ROM, 0xf000); // copy BASIC to RAM, which the undumped IPL is supposed to do.
360371   memcpy(m_p_videoram, ROM+0x1000, 0x1000);
361   //  membank("bank1")->set_base(RAM);
362372
363373   // probably not correct, exact meaning of port is unknown, vblank/vsync is too slow.
364374   m_sys_timer->adjust(attotime::from_usec(10),0,attotime::from_usec(10));
365   m_serial_timer->adjust(attotime::from_hz(500),0,attotime::from_hz(500));  // USART clock - this is a guesstimate
375   m_serial_timer->adjust(attotime::from_hz(19225),0,attotime::from_hz(19225));  // USART clock - this value loads a real tape
366376   m_timer_bit = 0;
377   m_cass_state = 1;
378   m_cass_data[0] = 0;
379   m_cass_data[1] = 0;
380   m_cass_data[2] = 0;
381   m_cass_data[3] = 0;
367382   m_beep->set_state(0);
368383   m_beep->set_frequency(950);    /* piezo-device needs to be measured */
369384}
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412427   DEVCB_NULL
413428};
414429
430TIMER_DEVICE_CALLBACK_MEMBER(alphatro_state::alphatro_c)
431{
432   m_cass_data[3]++;
433
434   if (m_cass_state)
435      m_cass->output(BIT(m_cass_data[3], 0) ? -1.0 : +1.0); // 2400Hz
436   else
437      m_cass->output(BIT(m_cass_data[3], 1) ? -1.0 : +1.0); // 1200Hz
438}
439
440TIMER_DEVICE_CALLBACK_MEMBER(alphatro_state::alphatro_p)
441{
442   /* cassette - turn 1200/2400Hz to a bit */
443   m_cass_data[1]++;
444   UINT8 cass_ws = (m_cass->input() > +0.03) ? 1 : 0;
445
446   if (cass_ws != m_cass_data[0])
447   {
448      m_cass_data[0] = cass_ws;
449      m_cass_data[2] = ((m_cass_data[1] < 12) ? 1 : 0);
450      m_cass_data[1] = 0;
451   }
452}
453
415454static const cassette_interface alphatro_cassette_interface =
416455{
417456   cassette_default_formats,
418457   NULL,
419   //(cassette_state) (CASSETTE_STOPPED | CASSETTE_MOTOR_ENABLED | CASSETTE_SPEAKER_ENABLED),
420458   (cassette_state) (CASSETTE_PLAY | CASSETTE_MOTOR_DISABLED | CASSETTE_SPEAKER_ENABLED),
421459   "alphatro_cass",
422460   NULL
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446484   MCFG_SOUND_WAVE_ADD(WAVE_TAG, "cassette")
447485   MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
448486
449
450487   /* Devices */
451488   MCFG_MC6845_ADD("crtc", MC6845, XTAL_12_288MHz / 8, alphatro_crtc6845_interface) // clk unknown
452489
453490   MCFG_I8251_ADD("usart", alphatro_usart_interface)
454491
455492   MCFG_CASSETTE_ADD("cassette", alphatro_cassette_interface)
493   MCFG_TIMER_DRIVER_ADD_PERIODIC("alphatro_c", alphatro_state, alphatro_c, attotime::from_hz(4800))
494   MCFG_TIMER_DRIVER_ADD_PERIODIC("alphatro_p", alphatro_state, alphatro_p, attotime::from_hz(40000))
456495
457496   MCFG_RAM_ADD("ram")
458497   MCFG_RAM_DEFAULT_SIZE("64K")

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