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(MESS) bbc.c: Hooking up some more serial processor features. Cassette saving is not working yet due to the serial procesor and 6850 not entirely understanding each other yet. (nw)

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This commit is contained in:
Wilbert Pol 2013-04-28 10:01:32 +00:00
parent 6947301824
commit b74602c6a9
3 changed files with 167 additions and 57 deletions
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4
src/mess/drivers/bbc.c
View File

@ -743,9 +743,9 @@ static ACIA6850_INTERFACE( bbc_acia6850_interface )
0,
0,
DEVCB_DRIVER_LINE_MEMBER(bbc_state,bbc_rxd_r),
DEVCB_NULL,
DEVCB_DRIVER_LINE_MEMBER(bbc_state,bbc_txd_w),
DEVCB_DRIVER_LINE_MEMBER(bbc_state,bbc_cts_r),
DEVCB_NULL,
DEVCB_DRIVER_LINE_MEMBER(bbc_state,bbc_rts_w),
DEVCB_DRIVER_LINE_MEMBER(bbc_state,bbc_dcd_r),
DEVCB_DRIVER_LINE_MEMBER(bbc_state,bbcb_acia6850_irq_w)
};

7
src/mess/includes/bbc.h
View File

@ -165,7 +165,12 @@ public:
int m_rxd_cass;
int m_rxd_rs423;
int m_cts_rs423;
int m_cass_out_enabled;
int m_txd;
UINT32 m_nr_high_tones;
int m_cass_out_samples_to_go;
int m_cass_out_bit;
int m_cass_out_phase;
emu_timer *m_tape_timer;
@ -330,6 +335,8 @@ public:
DECLARE_READ_LINE_MEMBER(bbc_rxd_r) { return ( m_serproc_data & 0x40 ) ? m_rxd_rs423 : m_rxd_cass; }
DECLARE_READ_LINE_MEMBER(bbc_dcd_r) { return ( m_serproc_data & 0x40 ) ? 0 : m_dcd_cass; }
DECLARE_READ_LINE_MEMBER(bbc_cts_r) { return ( m_serproc_data & 0x40 ) ? m_cts_rs423 : 1; }
DECLARE_WRITE_LINE_MEMBER(bbc_rts_w);
DECLARE_WRITE_LINE_MEMBER(bbc_txd_w);
DECLARE_DEVICE_IMAGE_LOAD_MEMBER( bbcb_cart );

213
src/mess/machine/bbc.c
View File

@ -1307,70 +1307,134 @@ void bbc_state::MC6850_Receive_Clock(int new_clock)
TIMER_CALLBACK_MEMBER(bbc_state::bbc_tape_timer_cb)
{
double dev_val = m_cassette->input();
// look for edges on the cassette wave
if (((dev_val>=0.0) && (m_last_dev_val<0.0)) || ((dev_val<0.0) && (m_last_dev_val>=0.0)))
if ( m_cass_out_enabled )
{
if (m_wav_len>(9*3))
{
//this is to long to recive anything so reset the serial IC. This is a hack, this should be done as a timer in the MC6850 code.
logerror ("Cassette length %d\n",m_wav_len);
m_nr_high_tones = 0;
m_dcd_cass = 0;
m_len0=0;
m_len1=0;
m_len2=0;
m_len3=0;
m_wav_len=0;
// 0 = 18-18 18-17-1
// 1 = 9-9-9-9 9-9-9-8-1
switch ( m_cass_out_samples_to_go )
{
case 0:
if ( m_cass_out_phase == 0 )
{
// get bit value
m_cass_out_bit = m_txd;
if ( m_cass_out_bit )
{
m_cass_out_phase = 3;
m_cass_out_samples_to_go = 9;
}
else
{
m_cass_out_phase = 1;
m_cass_out_samples_to_go = 18;
}
m_cassette->output( +1.0 );
}
else
{
// switch phase
m_cass_out_phase--;
m_cass_out_samples_to_go = m_cass_out_bit ? 9 : 18;
m_cassette->output( ( m_cass_out_phase & 1 ) ? +1.0 : -1.0 );
}
break;
case 1:
if ( m_cass_out_phase == 0 )
{
m_cassette->output( 0.0 );
}
break;
}
m_len3=m_len2;
m_len2=m_len1;
m_len1=m_len0;
m_len0=m_wav_len;
m_wav_len=0;
logerror ("cassette %d %d %d %d\n",m_len3,m_len2,m_len1,m_len0);
if ((m_len0+m_len1)>=(18+18-5))
{
/* Clock a 0 onto the serial line */
logerror("Serial value 0\n");
m_nr_high_tones = 0;
m_dcd_cass = 0;
MC6850_Receive_Clock(0);
m_len0=0;
m_len1=0;
m_len2=0;
m_len3=0;
}
if (((m_len0+m_len1+m_len2+m_len3)<=41) && (m_len3!=0))
{
/* Clock a 1 onto the serial line */
logerror("Serial value 1\n");
m_nr_high_tones++;
if ( m_nr_high_tones > 100 )
{
m_dcd_cass = 1;
}
MC6850_Receive_Clock(1);
m_len0=0;
m_len1=0;
m_len2=0;
m_len3=0;
}
m_cass_out_samples_to_go--;
}
else
{
double dev_val = m_cassette->input();
m_wav_len++;
m_last_dev_val=dev_val;
// look for edges on the cassette wave
if (((dev_val>=0.0) && (m_last_dev_val<0.0)) || ((dev_val<0.0) && (m_last_dev_val>=0.0)))
{
if (m_wav_len>(9*3))
{
//this is to long to recive anything so reset the serial IC. This is a hack, this should be done as a timer in the MC6850 code.
logerror ("Cassette length %d\n",m_wav_len);
m_nr_high_tones = 0;
m_dcd_cass = 0;
m_len0=0;
m_len1=0;
m_len2=0;
m_len3=0;
m_wav_len=0;
}
m_len3=m_len2;
m_len2=m_len1;
m_len1=m_len0;
m_len0=m_wav_len;
m_wav_len=0;
logerror ("cassette %d %d %d %d\n",m_len3,m_len2,m_len1,m_len0);
if ((m_len0+m_len1)>=(18+18-5))
{
/* Clock a 0 onto the serial line */
logerror("Serial value 0\n");
m_nr_high_tones = 0;
m_dcd_cass = 0;
MC6850_Receive_Clock(0);
m_len0=0;
m_len1=0;
m_len2=0;
m_len3=0;
}
if (((m_len0+m_len1+m_len2+m_len3)<=41) && (m_len3!=0))
{
/* Clock a 1 onto the serial line */
logerror("Serial value 1\n");
m_nr_high_tones++;
if ( m_nr_high_tones > 100 )
{
m_dcd_cass = 1;
}
MC6850_Receive_Clock(1);
m_len0=0;
m_len1=0;
m_len2=0;
m_len3=0;
}
}
m_wav_len++;
m_last_dev_val=dev_val;
}
}
WRITE_LINE_MEMBER( bbc_state::bbc_rts_w )
{
if ( m_serproc_data & 0x40 )
{
m_cass_out_enabled = 0;
}
else
{
m_cass_out_enabled = state ? 0 : 1;
}
}
WRITE_LINE_MEMBER( bbc_state::bbc_txd_w )
{
m_txd = state;
}
void bbc_state::BBC_Cassette_motor(unsigned char status)
{
if (status)
@ -1387,6 +1451,8 @@ void bbc_state::BBC_Cassette_motor(unsigned char status)
m_len2 = 0;
m_len3 = 0;
m_wav_len = 0;
m_cass_out_phase = 0;
m_cass_out_samples_to_go = 4;
}
}
@ -1397,11 +1463,46 @@ void bbc_state::BBC_Cassette_motor(unsigned char status)
// -x-- ---- - Cassette(0)/RS243 input(1)
// --xx x--- - Receive baud rate generator control
// ---- -xxx - Transmit baud rate generator control
// These possible settings apply to both the receive
// and transmit baud generator control bits:
// 000 - 16MHz / 13 / 1 - 19200 baud
// 001 - 16MHz / 13 / 16 - 1200 baud
// 010 - 16MHz / 13 / 4 - 4800 baud
// 011 - 16MHz / 13 / 128 - 150 baud
// 100 - 16MHz / 13 / 2 - 9600 baud
// 101 - 16MHz / 13 / 64 - 300 baud
// 110 - 16MHz / 13 / 8 - 2400 baud
// 110 - 16MHz / 13 / 256 - 75 baud
//
WRITE8_MEMBER(bbc_state::bbc_SerialULA_w)
{
static const int serial_clocks[8] =
{
XTAL_16MHz / 13 / 1, // 000
XTAL_16MHz / 13 / 16, // 001
XTAL_16MHz / 13 / 4, // 010
XTAL_16MHz / 13 / 128, // 011
XTAL_16MHz / 13 / 2, // 100
XTAL_16MHz / 13 / 64, // 101
XTAL_16MHz / 13 / 8, // 110
XTAL_16MHz / 13 / 256 // 111
};
m_serproc_data = data;
BBC_Cassette_motor(m_serproc_data & 0x80);
// Set transmit clock rate
m_acia->set_tx_clock( serial_clocks[ data & 0x07 ] );
if ( data & 0x40 )
{
// Set receive clock rate
m_acia->set_rx_clock( serial_clocks[ ( data >> 3 ) & 0x07 ] );
}
else
{
m_acia->set_rx_clock( 0 );
}
}
/**************************************
@ -1993,6 +2094,7 @@ DRIVER_INIT_MEMBER(bbc_state,bbc)
m_cts_rs423 = 1;
m_nr_high_tones = 0;
m_serproc_data = 0;
m_cass_out_enabled = 0;
m_tape_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(bbc_state::bbc_tape_timer_cb),this));
}
@ -2005,6 +2107,7 @@ DRIVER_INIT_MEMBER(bbc_state,bbcm)
m_cts_rs423 = 1;
m_nr_high_tones = 0;
m_serproc_data = 0;
m_cass_out_enabled = 0;
m_tape_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(bbc_state::bbc_tape_timer_cb),this));
}