summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/drivers/kim1.cpp
blob: fa2a39ff1f7045534142631fb1df720e8d178fff (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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
// license:GPL-2.0+
// copyright-holders:Juergen Buchmueller
/******************************************************************************

    kim1.cpp - KIM-1

    LED: six 7-segment LEDs
        left 4 digits (address)
        right 2 digits (data)
    Keyboard: 23 keys and SST switch
        0-F  16 keys to enter data
        AD   address entry mode
        DA   data entry mode
        +    increment address
        PC   recalls address stored in the Program Counter
        RS   system reset
        GO   execute program
        ST   program stop
        SST  single step slide switch

    How to use cassette:
        00F1      00 to clear decimal mode
        17F5-17F6 start address low and high
        17F7-17F8 end address low and high
        17F9      2 digit program ID
        1800      press GO to save tape
        1873      press GO to load tape
    NOTE: save end address is next address from program end

The cassette interface
======================
The KIM-1 stores data on cassette using 2 frequencies: ~3700Hz (high) and ~2400Hz
(low). A high tone is output for 9 cycles and a low tone for 6 cycles. A logic bit
is encoded using 3 sequences of high and low tones. It always starts with a high
tone and ends with a low tone. The middle tone is high for a logic 0 and low for
0 logic 1.

These high and low tone signals are fed to a circuit containing a LM565 PLL and
a 311 comparator. For a high tone a 1 is passed to DB7 of 6530-U2 for a low tone
a 0 is passed. The KIM-1 software measures the time it takes for the signal to
change from 1 to 0.

Keyboard and Display logic
==========================
PA0-PA6 of 6530-U2 are connected to the columns of the keyboard matrix. These
columns are also connected to segments A-G of the LEDs. PB1-PB3 of 6530-U2 are
connected to a 74145 BCD which connects outputs 0-2 to the rows of the keyboard
matrix. Outputs 4-9 of the 74145 are connected to LEDs U18-U23

When a key is pressed the corresponding input to PA0-PA6 is set low and the KIM-1
software reads this signal. The KIM-1 software sends an output signal to PA0-PA6
and the corresponding segments of an LED are illuminated.

TODO:
- LEDs should be dark at startup (RS key to activate)
- hook up Single Step dip switch
- slots for expansion & application ports
- add TTY support
******************************************************************************/

#include "emu.h"
#include "includes/kim1.h"
#include "kim1.lh"

//**************************************************************************
//  ADDRESS MAPS
//**************************************************************************

void kim1_state::kim1_map(address_map &map)
{
	map(0x0000, 0x03ff).mirror(0xe000).ram();
	map(0x1700, 0x173f).mirror(0xe000).rw("miot_u3", FUNC(mos6530_device::read), FUNC(mos6530_device::write));
	map(0x1740, 0x177f).mirror(0xe000).rw(m_riot2, FUNC(mos6530_device::read), FUNC(mos6530_device::write));
	map(0x1780, 0x17bf).mirror(0xe000).ram();
	map(0x17c0, 0x17ff).mirror(0xe000).ram();
	map(0x1800, 0x1bff).mirror(0xe000).rom();
	map(0x1c00, 0x1fff).mirror(0xe000).rom();
}

// RS and ST key input
INPUT_CHANGED_MEMBER(kim1_state::trigger_reset)
{
		m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? CLEAR_LINE : ASSERT_LINE);
}

INPUT_CHANGED_MEMBER(kim1_state::trigger_nmi)
{
		m_maincpu->set_input_line(INPUT_LINE_NMI, newval ? CLEAR_LINE : ASSERT_LINE);
}

//**************************************************************************
//  INPUT PORTS
//**************************************************************************

static INPUT_PORTS_START( kim1 )
	PORT_START("ROW0")
	PORT_BIT( 0x80, 0x00, IPT_UNUSED )
	PORT_BIT( 0x40, 0x40, IPT_KEYBOARD ) PORT_NAME("0") PORT_CODE(KEYCODE_0)      PORT_CHAR('0') PORT_CODE(KEYCODE_0_PAD)
	PORT_BIT( 0x20, 0x20, IPT_KEYBOARD ) PORT_NAME("1") PORT_CODE(KEYCODE_1)      PORT_CHAR('1') PORT_CODE(KEYCODE_1_PAD)
	PORT_BIT( 0x10, 0x10, IPT_KEYBOARD ) PORT_NAME("2") PORT_CODE(KEYCODE_2)      PORT_CHAR('2') PORT_CODE(KEYCODE_2_PAD)
	PORT_BIT( 0x08, 0x08, IPT_KEYBOARD ) PORT_NAME("3") PORT_CODE(KEYCODE_3)      PORT_CHAR('3') PORT_CODE(KEYCODE_3_PAD)
	PORT_BIT( 0x04, 0x04, IPT_KEYBOARD ) PORT_NAME("4") PORT_CODE(KEYCODE_4)      PORT_CHAR('4') PORT_CODE(KEYCODE_4_PAD)
	PORT_BIT( 0x02, 0x02, IPT_KEYBOARD ) PORT_NAME("5") PORT_CODE(KEYCODE_5)      PORT_CHAR('5') PORT_CODE(KEYCODE_5_PAD)
	PORT_BIT( 0x01, 0x01, IPT_KEYBOARD ) PORT_NAME("6") PORT_CODE(KEYCODE_6)      PORT_CHAR('6') PORT_CODE(KEYCODE_6_PAD)

	PORT_START("ROW1")
	PORT_BIT( 0x80, 0x00, IPT_UNUSED )
	PORT_BIT( 0x40, 0x40, IPT_KEYBOARD ) PORT_NAME("7") PORT_CODE(KEYCODE_7)      PORT_CHAR('7') PORT_CODE(KEYCODE_7_PAD)
	PORT_BIT( 0x20, 0x20, IPT_KEYBOARD ) PORT_NAME("8") PORT_CODE(KEYCODE_8)      PORT_CHAR('8') PORT_CODE(KEYCODE_8_PAD)
	PORT_BIT( 0x10, 0x10, IPT_KEYBOARD ) PORT_NAME("9") PORT_CODE(KEYCODE_9)      PORT_CHAR('9') PORT_CODE(KEYCODE_9_PAD)
	PORT_BIT( 0x08, 0x08, IPT_KEYBOARD ) PORT_NAME("A") PORT_CODE(KEYCODE_A)      PORT_CHAR('A')
	PORT_BIT( 0x04, 0x04, IPT_KEYBOARD ) PORT_NAME("B") PORT_CODE(KEYCODE_B)      PORT_CHAR('B')
	PORT_BIT( 0x02, 0x02, IPT_KEYBOARD ) PORT_NAME("C") PORT_CODE(KEYCODE_C)      PORT_CHAR('C')
	PORT_BIT( 0x01, 0x01, IPT_KEYBOARD ) PORT_NAME("D") PORT_CODE(KEYCODE_D)      PORT_CHAR('D')

	PORT_START("ROW2")
	PORT_BIT( 0x80, 0x00, IPT_UNUSED )
	PORT_BIT( 0x40, 0x40, IPT_KEYBOARD ) PORT_NAME("E")  PORT_CODE(KEYCODE_E)      PORT_CHAR('E')
	PORT_BIT( 0x20, 0x20, IPT_KEYBOARD ) PORT_NAME("F")  PORT_CODE(KEYCODE_F)      PORT_CHAR('F')
	PORT_BIT( 0x10, 0x10, IPT_KEYBOARD ) PORT_NAME("AD") PORT_CODE(KEYCODE_MINUS)  PORT_CHAR('-') PORT_CODE(KEYCODE_MINUS_PAD)
	PORT_BIT( 0x08, 0x08, IPT_KEYBOARD ) PORT_NAME("DA") PORT_CODE(KEYCODE_EQUALS) PORT_CHAR('=')
	PORT_BIT( 0x04, 0x04, IPT_KEYBOARD ) PORT_NAME("+")  PORT_CODE(KEYCODE_UP)     PORT_CHAR(' ') PORT_CODE(KEYCODE_PLUS_PAD)
	PORT_BIT( 0x02, 0x02, IPT_KEYBOARD ) PORT_NAME("GO") PORT_CODE(KEYCODE_ENTER)  PORT_CHAR(13)  PORT_CODE(KEYCODE_ENTER_PAD)
	PORT_BIT( 0x01, 0x01, IPT_KEYBOARD ) PORT_NAME("PC") PORT_CODE(KEYCODE_F6)

	PORT_START("SPECIAL")
	PORT_BIT( 0x80, 0x00, IPT_UNUSED )
	PORT_BIT( 0x40, 0x40, IPT_KEYBOARD ) PORT_NAME("sw1: ST") PORT_CODE(KEYCODE_F7) PORT_CHANGED_MEMBER(DEVICE_SELF, kim1_state, trigger_nmi, nullptr)
	PORT_BIT( 0x20, 0x20, IPT_KEYBOARD ) PORT_NAME("sw2: RS") PORT_CODE(KEYCODE_F3) PORT_CHANGED_MEMBER(DEVICE_SELF, kim1_state, trigger_reset, nullptr)
	PORT_DIPNAME(0x10, 0x10, "sw3: SS")                       PORT_CODE(KEYCODE_NUMLOCK) PORT_TOGGLE
	PORT_DIPSETTING( 0x00, "single step")
	PORT_DIPSETTING( 0x10, "run")
	PORT_BIT( 0x08, 0x00, IPT_UNUSED )
	PORT_BIT( 0x04, 0x00, IPT_UNUSED )
	PORT_BIT( 0x02, 0x00, IPT_UNUSED )
	PORT_BIT( 0x01, 0x00, IPT_UNUSED )
INPUT_PORTS_END

// Read from keyboard
READ8_MEMBER( kim1_state::kim1_u2_read_a )
{
	uint8_t data = 0xff;

	offs_t const sel = ( m_u2_port_b >> 1 ) & 0x0f;
	if ( 3U > sel )
		data = m_row[sel]->read();

	return data;
}

// Write to 7-Segment LEDs
WRITE8_MEMBER( kim1_state::kim1_u2_write_a )
{
	uint8_t idx = ( m_u2_port_b >> 1 ) & 0x0f;

	if ( idx >= 4 && idx < 10 )
	{
		if ( data & 0x80 )
		{
			m_digit[idx - 4] = data & 0x7f;
			m_led_time[idx - 4] = 15;
		}
	}
}

// Load from cassette
READ8_MEMBER( kim1_state::kim1_u2_read_b )
{
	if ( m_riot2->portb_out_get() & 0x20 )
		return 0xFF;

	return 0x7F | ( m_311_output ^ 0x80 );
}

// Save to cassette
WRITE8_MEMBER( kim1_state::kim1_u2_write_b )
{
	m_u2_port_b = data;

	if ( data & 0x20 )
		/* cassette write/speaker update */
		m_cass->output(( data & 0x80 ) ? -1.0 : 1.0 );

	/* Set IRQ when bit 7 is cleared */
}

TIMER_DEVICE_CALLBACK_MEMBER(kim1_state::kim1_cassette_input)
{
	double tap_val = m_cass->input();

	if ( tap_val <= 0 )
	{
		if ( m_cassette_high_count )
		{
			m_311_output = ( m_cassette_high_count < 8 ) ? 0x80 : 0;
			m_cassette_high_count = 0;
		}
	}

	if ( tap_val > 0 )
		m_cassette_high_count++;
}

// Blank LEDs during cassette operations
TIMER_DEVICE_CALLBACK_MEMBER(kim1_state::kim1_update_leds)
{
	uint8_t i;

	for ( i = 0; i < 6; i++ )
	{
		if ( m_led_time[i] )
			m_led_time[i]--;
		else
			m_digit[i] = 0;
	}
}

// Register for save states
void kim1_state::machine_start()
{
	m_digit.resolve();

	save_item(NAME(m_u2_port_b));
	save_item(NAME(m_311_output));
	save_item(NAME(m_cassette_high_count));
}

void kim1_state::machine_reset()
{
	uint8_t i;

	for ( i = 0; i < 6; i++ )
		m_led_time[i] = 0;

	m_311_output = 0;
	m_cassette_high_count = 0;
}

//**************************************************************************
//  MACHINE DRIVERS
//**************************************************************************

MACHINE_CONFIG_START(kim1_state::kim1)
	// basic machine hardware
	MCFG_DEVICE_ADD("maincpu", M6502, 1000000)        /* 1 MHz */
	MCFG_DEVICE_PROGRAM_MAP(kim1_map)
	MCFG_QUANTUM_TIME(attotime::from_hz(60))

	// video hardware
	MCFG_DEFAULT_LAYOUT( layout_kim1 )

	// devices
	MCFG_DEVICE_ADD("miot_u2", MOS6530, 1000000)
	MCFG_MOS6530_IN_PA_CB(READ8(*this, kim1_state, kim1_u2_read_a))
	MCFG_MOS6530_OUT_PA_CB(WRITE8(*this, kim1_state, kim1_u2_write_a))
	MCFG_MOS6530_IN_PB_CB(READ8(*this, kim1_state, kim1_u2_read_b))
	MCFG_MOS6530_OUT_PB_CB(WRITE8(*this, kim1_state, kim1_u2_write_b))

	MCFG_DEVICE_ADD("miot_u3", MOS6530, 1000000)

	MCFG_CASSETTE_ADD( "cassette" )
	MCFG_CASSETTE_FORMATS(kim1_cassette_formats)
	MCFG_CASSETTE_DEFAULT_STATE(CASSETTE_STOPPED)
	MCFG_CASSETTE_INTERFACE ("kim1_cass")

	MCFG_TIMER_DRIVER_ADD_PERIODIC("led_timer", kim1_state, kim1_update_leds, attotime::from_hz(60))
	MCFG_TIMER_DRIVER_ADD_PERIODIC("cassette_timer", kim1_state, kim1_cassette_input, attotime::from_hz(44100))

	// software list
	MCFG_SOFTWARE_LIST_ADD ("cass_list", "kim1_cass")

MACHINE_CONFIG_END

//**************************************************************************
//  ROM DEFINITIONS
//**************************************************************************

ROM_START(kim1)
	ROM_REGION(0x10000,"maincpu",0)
	ROM_LOAD("6530-003.bin",    0x1800, 0x0400, CRC(a2a56502) SHA1(60b6e48f35fe4899e29166641bac3e81e3b9d220))
	ROM_LOAD("6530-002.bin",    0x1c00, 0x0400, CRC(2b08e923) SHA1(054f7f6989af3a59462ffb0372b6f56f307b5362))
ROM_END

//**************************************************************************
//  SYSTEM DRIVERS
//**************************************************************************

//    YEAR  NAME  PARENT  COMPAT  MACHINE  INPUT  CLASS       INIT        COMPANY             FULLNAME  FLAGS
COMP( 1975, kim1, 0,      0,      kim1,    kim1,  kim1_state, empty_init, "MOS Technologies", "KIM-1",  MACHINE_NO_SOUND_HW | MACHINE_SUPPORTS_SAVE)