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(MESS) D6800: Cassette connected up, system marked as WORKING [Robbbert]

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Robbbert 2013-05-08 14:04:25 +00:00
parent 9247f1bd34
commit 19a36083f9
1 changed files with 23 additions and 9 deletions
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32
src/mess/drivers/d6800.c
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@ -11,12 +11,16 @@
NOTE that the display only updates after each 4 digits is entered, and
you can't see what you type as you change bytes. This is by design.
The cassette has no checksum, header or blocks. It is simply a stream
of pulses. The successful loading of a tape is therefore a matter of luck.
Function keys:
FN 0 - Modify memory - firstly enter a 4-digit address, then 2-digit data
the address will increment by itself, enter the next byte.
FN by itself will step to the next address.
FN 1 - Tape load
FN 1 - Tape load. You must have entered the start address at 0002, and
the end address+1 at 0004 (big-endian).
FN 2 - Tape save. You must have entered the start address at 0002, and
the end address+1 at 0004 (big-endian).
@ -29,9 +33,6 @@
Information and programs can be found at http://chip8.com/?page=78
TODO:
- Cassette
*/
@ -73,6 +74,7 @@ public:
DECLARE_READ_LINE_MEMBER( d6800_rtc_pulse );
DECLARE_WRITE_LINE_MEMBER( d6800_screen_w );
UINT32 screen_update_d6800(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
TIMER_DEVICE_CALLBACK_MEMBER(d6800_c);
TIMER_DEVICE_CALLBACK_MEMBER(d6800_p);
DECLARE_QUICKLOAD_LOAD_MEMBER( d6800 );
protected:
@ -96,7 +98,7 @@ private:
bool m_ca2;
bool m_cb1;
bool m_cb2;
UINT8 m_cass_data[3];
UINT8 m_cass_data[4];
UINT8 m_portb;
virtual void machine_start();
virtual void machine_reset();
@ -208,8 +210,19 @@ UINT32 d6800_state::screen_update_d6800(screen_device &screen, bitmap_ind16 &bit
return 0;
}
/* PIA6821 Interface */
/* NE556 */
TIMER_DEVICE_CALLBACK_MEMBER(d6800_state::d6800_c)
{
m_cass_data[3]++;
if (BIT(m_portb, 0))
m_cass->output(BIT(m_cass_data[3], 0) ? -1.0 : +1.0); // 2400Hz
else
m_cass->output(BIT(m_cass_data[3], 1) ? -1.0 : +1.0); // 1200Hz
}
/* PIA6821 Interface */
TIMER_DEVICE_CALLBACK_MEMBER(d6800_state::d6800_p)
{
@ -233,7 +246,7 @@ TIMER_DEVICE_CALLBACK_MEMBER(d6800_state::d6800_p)
if (cass_ws != m_cass_data[0])
{
m_cass_data[0] = cass_ws;
m_cass_data[2] = ((m_cass_data[1] < 12) ? 0 : 128);
m_cass_data[2] = ((m_cass_data[1] < 12) ? 128 : 0);
m_cass_data[1] = 0;
}
}
@ -280,7 +293,6 @@ WRITE8_MEMBER( d6800_state::d6800_cassette_w )
are in progress (DMA/CB2 line low).
*/
m_cass->output(BIT(data, 0) ? -1.0 : +1.0);
m_beeper->set_frequency(BIT(data, 0) ? 2400 : 1200);
m_beeper->set_state(BIT(data, 6) & m_cb2);
@ -348,6 +360,7 @@ void d6800_state::machine_reset()
m_cass_data[0] = 0;
m_cass_data[1] = 0;
m_cass_data[2] = 128;
m_cass_data[3] = 0;
}
/* Machine Drivers */
@ -433,6 +446,7 @@ static MACHINE_CONFIG_START( d6800, d6800_state )
/* devices */
MCFG_PIA6821_ADD("pia", d6800_mc6821_intf)
MCFG_CASSETTE_ADD("cassette", d6800_cassette_interface)
MCFG_TIMER_DRIVER_ADD_PERIODIC("d6800_c", d6800_state, d6800_c, attotime::from_hz(4800))
MCFG_TIMER_DRIVER_ADD_PERIODIC("d6800_p", d6800_state, d6800_p, attotime::from_hz(40000))
/* quickload */
@ -451,4 +465,4 @@ ROM_START( d6800 )
ROM_END
/* YEAR NAME PARENT COMPAT MACHINE INPUT CLASS, INIT COMPANY FULLNAME FLAGS */
COMP( 1979, d6800, 0, 0, d6800, d6800, driver_device, 0, "Michael Bauer", "Dream 6800", GAME_NOT_WORKING )
COMP( 1979, d6800, 0, 0, d6800, d6800, driver_device, 0, "Michael Bauer", "Dream 6800", 0 )