1 // license:BSD-3-Clause
2 // copyright-holders:Curt Coder
3 /**********************************************************************
4 
5     Rex Datentechnik 256KB EPROM cartridge emulation
6 
7 **********************************************************************/
8 
9 #include "emu.h"
10 #include "rex_ep256.h"
11 
12 
13 
14 //**************************************************************************
15 //  DEVICE DEFINITIONS
16 //**************************************************************************
17 
18 DEFINE_DEVICE_TYPE(C64_REX_EP256, c64_rex_ep256_cartridge_device, "c64_rex_ep256", "C64 Rex 256KB EPROM cartridge")
19 
20 
21 //-------------------------------------------------
22 //  device_add_mconfig - add device configuration
23 //-------------------------------------------------
24 
device_add_mconfig(machine_config & config)25 void c64_rex_ep256_cartridge_device::device_add_mconfig(machine_config &config)
26 {
27 	for (auto &eprom : m_eproms)
28 		GENERIC_SOCKET(config, eprom, generic_linear_slot, nullptr, "bin,rom");
29 }
30 
31 
32 
33 //**************************************************************************
34 //  LIVE DEVICE
35 //**************************************************************************
36 
37 //-------------------------------------------------
38 //  c64_rex_ep256_cartridge_device - constructor
39 //-------------------------------------------------
40 
c64_rex_ep256_cartridge_device(const machine_config & mconfig,const char * tag,device_t * owner,uint32_t clock)41 c64_rex_ep256_cartridge_device::c64_rex_ep256_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
42 	device_t(mconfig, C64_REX_EP256, tag, owner, clock),
43 	device_c64_expansion_card_interface(mconfig, *this),
44 	m_eproms(*this, "rom%u", 1U)
45 {
46 }
47 
48 
49 //-------------------------------------------------
50 //  device_start - device-specific startup
51 //-------------------------------------------------
52 
device_start()53 void c64_rex_ep256_cartridge_device::device_start()
54 {
55 	// state saving
56 	save_item(NAME(m_bank));
57 	save_item(NAME(m_reset));
58 	save_item(NAME(m_socket));
59 }
60 
61 
62 //-------------------------------------------------
63 //  device_reset - device-specific reset
64 //-------------------------------------------------
65 
device_reset()66 void c64_rex_ep256_cartridge_device::device_reset()
67 {
68 	m_exrom = 0;
69 	m_reset = 1;
70 	m_bank = 0;
71 	m_socket = 0;
72 }
73 
74 
75 //-------------------------------------------------
76 //  c64_cd_r - cartridge data read
77 //-------------------------------------------------
78 
c64_cd_r(offs_t offset,uint8_t data,int sphi2,int ba,int roml,int romh,int io1,int io2)79 uint8_t c64_rex_ep256_cartridge_device::c64_cd_r(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2)
80 {
81 	if (!roml)
82 	{
83 		if (m_reset)
84 		{
85 			data = m_roml[offset & 0x1fff];
86 		}
87 		else
88 		{
89 			offs_t addr = (m_bank << 13) | (offset & 0x1fff);
90 			data = m_eproms[m_socket]->read_rom(addr);
91 		}
92 	}
93 	else if (!io2)
94 	{
95 		if ((offset & 0xf0) == 0xc0)
96 		{
97 			m_exrom = 1;
98 		}
99 		else if ((offset & 0xf0) == 0xe0)
100 		{
101 			m_exrom = 0;
102 		}
103 	}
104 
105 	return data;
106 }
107 
108 
109 //-------------------------------------------------
110 //  c64_cd_w - cartridge data write
111 //-------------------------------------------------
112 
c64_cd_w(offs_t offset,uint8_t data,int sphi2,int ba,int roml,int romh,int io1,int io2)113 void c64_rex_ep256_cartridge_device::c64_cd_w(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2)
114 {
115 	if (!io2 && ((offset & 0xf0) == 0xa0))
116 	{
117 		/*
118 
119 		    bit     description
120 
121 		    0       socket selection bit 0
122 		    1       socket selection bit 1
123 		    2       socket selection bit 2
124 		    3
125 		    4
126 		    5       bank selection bit 0
127 		    6       bank selection bit 1
128 		    7
129 
130 		*/
131 
132 		m_reset = 0;
133 
134 		m_socket = data & 0x07;
135 		m_bank = (data >> 5) & 0x03;
136 	}
137 }
138