summaryrefslogtreecommitdiffstats
path: root/src/devices/bus/ss50/mpc.cpp
blob: 8489e23e29bd8fb1036871522032cd116b2db108 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
// license:BSD-3-Clause
// copyright-holders:AJR
/**********************************************************************

    SWTPC MP-C Serial Control Interface

**********************************************************************/

#include "emu.h"
#include "mpc.h"

#include "bus/rs232/rs232.h"
#include "machine/6821pia.h"
#include "machine/input_merger.h"
#include "machine/ripple_counter.h"

//**************************************************************************
//  TYPE DEFINITIONS
//**************************************************************************

// ======================> ss50_mpc_device

class ss50_mpc_device : public device_t, public ss50_card_interface
{
public:
	// construction/destruction
	ss50_mpc_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
		: device_t(mconfig, SS50_MPC, tag, owner, clock),
			ss50_card_interface(mconfig, *this),
			m_pia(*this, "pia"),
			m_loopback(*this, "loopback"),
			m_counter(*this, "counter"),
			m_baud_jumper(*this, "BAUD"),
			m_count_select(false)
	{
	}

protected:
	// device-specific overrides
	virtual ioport_constructor device_input_ports() const override;
	virtual void device_add_mconfig(machine_config &config) override;
	virtual void device_start() override;

	// interface-specific overrides
	virtual DECLARE_READ8_MEMBER(register_read) override;
	virtual DECLARE_WRITE8_MEMBER(register_write) override;
	virtual DECLARE_WRITE_LINE_MEMBER(f110_w) override;
	virtual DECLARE_WRITE_LINE_MEMBER(f300_w) override;

private:
	DECLARE_WRITE_LINE_MEMBER(serial_input_w);
	DECLARE_WRITE_LINE_MEMBER(reader_control_w);
	DECLARE_READ_LINE_MEMBER(count_r);
	DECLARE_WRITE_LINE_MEMBER(count_select_w);

	required_device<pia6821_device> m_pia;
	required_device<input_merger_device> m_loopback;
	required_device<ripple_counter_device> m_counter;
	required_ioport m_baud_jumper;

	bool m_count_select;
};


static INPUT_PORTS_START( mpc )
	PORT_START("BAUD")
	PORT_DIPNAME(1, 0, "Baud Rate")
	PORT_DIPSETTING(1, "110")
	PORT_DIPSETTING(0, "300")

	PORT_START("STOP")
	PORT_DIPNAME(1, 0, "Stop Bits")
	PORT_DIPSETTING(0, "1")
	PORT_DIPSETTING(1, "2")
INPUT_PORTS_END


//-------------------------------------------------
//  input_ports - device-specific input ports
//-------------------------------------------------

ioport_constructor ss50_mpc_device::device_input_ports() const
{
	return INPUT_PORTS_NAME(mpc);
}


static DEVICE_INPUT_DEFAULTS_START( terminal )
	DEVICE_INPUT_DEFAULTS("RS232_RXBAUD", 0xff, RS232_BAUD_300)
	DEVICE_INPUT_DEFAULTS("RS232_TXBAUD", 0xff, RS232_BAUD_300)
	DEVICE_INPUT_DEFAULTS("RS232_STARTBITS", 0xff, RS232_STARTBITS_1)
	DEVICE_INPUT_DEFAULTS("RS232_DATABITS", 0xff, RS232_DATABITS_8)
	DEVICE_INPUT_DEFAULTS("RS232_PARITY", 0xff, RS232_PARITY_NONE)
	DEVICE_INPUT_DEFAULTS("RS232_STOPBITS", 0xff, RS232_STOPBITS_1)
DEVICE_INPUT_DEFAULTS_END


//-------------------------------------------------
//  device_add_mconfig - add device-specific
//  machine configuration
//-------------------------------------------------

MACHINE_CONFIG_START(ss50_mpc_device::device_add_mconfig)
	MCFG_DEVICE_ADD("pia", PIA6821, 0) // actually MC6820
	MCFG_PIA_WRITEPA_HANDLER(WRITELINE("outgate", input_merger_device, in_w<0>)) MCFG_DEVCB_BIT(0)
	MCFG_PIA_CB2_HANDLER(WRITELINE(*this, ss50_mpc_device, reader_control_w))
	MCFG_PIA_READPB_HANDLER(IOPORT("STOP")) MCFG_DEVCB_BIT(6)
	MCFG_DEVCB_CHAIN_INPUT(READLINE(*this, ss50_mpc_device, count_r)) MCFG_DEVCB_BIT(7)
	MCFG_PIA_WRITEPB_HANDLER(WRITELINE(*this, ss50_mpc_device, count_select_w)) MCFG_DEVCB_BIT(2)
	MCFG_DEVCB_CHAIN_OUTPUT(WRITELINE("counter", ripple_counter_device, reset_w)) MCFG_DEVCB_BIT(0)
	//MCFG_PIA_IRQA_HANDLER(WRITELINE(*this, ss50_mpc_device, pia_irq_w))
	//MCFG_PIA_IRQB_HANDLER(WRITELINE(*this, ss50_mpc_device, pia_irq_w))

	MCFG_DEVICE_ADD("rs232", RS232_PORT, default_rs232_devices, "terminal")
	MCFG_RS232_RXD_HANDLER(WRITELINE(*this, ss50_mpc_device, serial_input_w))
	MCFG_SLOT_OPTION_DEVICE_INPUT_DEFAULTS("terminal", terminal)

	MCFG_INPUT_MERGER_ALL_HIGH("outgate")
	MCFG_INPUT_MERGER_OUTPUT_HANDLER(WRITELINE("rs232", rs232_port_device, write_txd))

	MCFG_INPUT_MERGER_ANY_HIGH("loopback")
	MCFG_INPUT_MERGER_OUTPUT_HANDLER(WRITELINE("outgate", input_merger_device, in_w<1>))

	MCFG_DEVICE_ADD("counter", RIPPLE_COUNTER, 0) // CD4024AE (IC3)
	MCFG_RIPPLE_COUNTER_STAGES(7) // only Q5 (÷32) and Q4 (÷16) are actually used
MACHINE_CONFIG_END


//-------------------------------------------------
//  device_start - device-specific startup
//-------------------------------------------------

void ss50_mpc_device::device_start()
{
	save_item(NAME(m_count_select));
}

WRITE_LINE_MEMBER(ss50_mpc_device::serial_input_w)
{
	m_pia->set_a_input(state << 7, 0x7f);
	m_loopback->in_w<0>(state);
}


WRITE_LINE_MEMBER(ss50_mpc_device::reader_control_w)
{
	m_loopback->in_w<1>(state);
}

READ_LINE_MEMBER(ss50_mpc_device::count_r)
{
	return BIT(m_counter->count(), m_count_select ? 4 : 3);
}

WRITE_LINE_MEMBER(ss50_mpc_device::count_select_w)
{
	m_count_select = bool(state);
}


//-------------------------------------------------
//  register_read - read from a port register
//-------------------------------------------------

READ8_MEMBER(ss50_mpc_device::register_read)
{
	return m_pia->read(space, offset & 3, 0);
}

//-------------------------------------------------
//  register_write - write to a port register
//-------------------------------------------------

WRITE8_MEMBER(ss50_mpc_device::register_write)
{
	m_pia->write(space, offset & 3, data);
}

WRITE_LINE_MEMBER(ss50_mpc_device::f110_w)
{
	if (m_baud_jumper->read())
		m_counter->clock_w(state);
}

WRITE_LINE_MEMBER(ss50_mpc_device::f300_w)
{
	if (!m_baud_jumper->read())
		m_counter->clock_w(state);
}


// device type definition
DEFINE_DEVICE_TYPE_PRIVATE(SS50_MPC, ss50_card_interface, ss50_mpc_device, "ss50_mpc", "MP-C Serial Control Interface")