summaryrefslogtreecommitdiffstatshomepage
path: root/src/emu/bus/c64/pagefox.c
blob: 2edc58983c64a9ad7c24cb8effd04cd0f8ce86ac (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
// license:BSD-3-Clause
// copyright-holders:Curt Coder
/**********************************************************************

    Scanntronik Pagefox cartridge emulation

    Copyright MESS Team.
    Visit http://mamedev.org for licensing and usage restrictions.

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

/*

    PCB Layout
    ----------

    |===========================|
    |=|                         |
    |=|     RAM         LS11    |
    |=|                         |
    |=|                 LS139   |
    |=|     ROM0                |
    |=|                 LS273   |
    |=|                         |
    |=|     ROM1        LS00    |
    |===========================|

    RAM   - NEC D43256-12L 32Kx8 RAM
    ROM0  - SGS M27256-2FI 32Kx8 EPROM
    ROM1  - National Instruments NMC27C256Q 32Kx8 EPROM

*/

#include "pagefox.h"



//**************************************************************************
//  DEVICE DEFINITIONS
//**************************************************************************

const device_type C64_PAGEFOX = &device_creator<c64_pagefox_cartridge_device>;



//**************************************************************************
//  LIVE DEVICE
//**************************************************************************

//-------------------------------------------------
//  c64_pagefox_cartridge_device - constructor
//-------------------------------------------------

c64_pagefox_cartridge_device::c64_pagefox_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
	device_t(mconfig, C64_PAGEFOX, "C64 Pagefox cartridge", tag, owner, clock, "c64_pagefox", __FILE__),
	device_c64_expansion_card_interface(mconfig, *this),
	m_ram(*this, "ram")
{
}


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

void c64_pagefox_cartridge_device::device_start()
{
	// allocate memory
	m_ram.allocate(0x8000);
	
	// state saving
	save_item(NAME(m_bank));
}


//-------------------------------------------------
//  device_reset - device-specific reset
//-------------------------------------------------

void c64_pagefox_cartridge_device::device_reset()
{
	m_bank = 0;
}


//-------------------------------------------------
//  c64_cd_r - cartridge data read
//-------------------------------------------------

UINT8 c64_pagefox_cartridge_device::c64_cd_r(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
{
	if (!roml || !romh)
	{
		if (BIT(m_bank, 3))
		{
			offs_t addr = (BIT(m_bank, 1) << 14) | (offset & 0x3fff);
			data = m_ram[addr];
		}
		else
		{
			int bank = (m_bank >> 1) & 0x07;
			offs_t addr = (bank << 14) | (offset & 0x3fff);
			data = m_roml[addr];
		}
	}

	return data;
}


//-------------------------------------------------
//  c64_cd_w - cartridge data write
//-------------------------------------------------

void c64_pagefox_cartridge_device::c64_cd_w(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
{
	if (offset >= 0x8000 && offset < 0xc000)
	{
		if (BIT(m_bank, 3))
		{
			offs_t addr = (BIT(m_bank, 1) << 14) | (offset & 0x3fff);
			m_ram[addr] = data;
		}
	}
	else if (!io1 && BIT(offset, 7))
	{
		if (data == 0xff)
		{
			m_game = 1;
			m_exrom = 1;
		}
		else
		{
			m_game = 0;
			m_exrom = 0;
		}

		m_bank = data;
	}
}