1 // license:BSD-3-Clause
2 // copyright-holders:Curt Coder
3 /**********************************************************************
4
5 VizaStar 64 XL4 cartridge emulation
6
7 **********************************************************************/
8
9 /*
10
11 PCB Layout
12 ----------
13 RB84 (C) MICROPORT
14 |===========================|
15 |=| |
16 |=| |
17 |=| |
18 |=| |
19 |=| ROM |
20 |=| |
21 |=| |
22 |=| |
23 |===========================|
24
25 ROM - Hitachi HN462732G 4Kx8 EPROM "V"
26
27 */
28
29 #include "emu.h"
30 #include "vizastar.h"
31
32
33
34 //**************************************************************************
35 // MACROS/CONSTANTS
36 //**************************************************************************
37
38 #define UNSCRAMBLE_ADDRESS(_offset) \
39 bitswap<16>(_offset,15,14,13,12,5,0,7,10,11,9,8,6,4,3,2,1)
40
41 #define UNSCRAMBLE_DATA(_data) \
42 bitswap<8>(_data,7,6,0,5,1,4,2,3)
43
44
45
46 //**************************************************************************
47 // DEVICE DEFINITIONS
48 //**************************************************************************
49
50 DEFINE_DEVICE_TYPE(C64_VIZASTAR, c64_vizastar_cartridge_device, "c64_vizastar", "VizaStar 64 XL4")
51
52
53
54 //**************************************************************************
55 // LIVE DEVICE
56 //**************************************************************************
57
58 //-------------------------------------------------
59 // c64_vizastar_cartridge_device - constructor
60 //-------------------------------------------------
61
c64_vizastar_cartridge_device(const machine_config & mconfig,const char * tag,device_t * owner,uint32_t clock)62 c64_vizastar_cartridge_device::c64_vizastar_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
63 device_t(mconfig, C64_VIZASTAR, tag, owner, clock),
64 device_c64_expansion_card_interface(mconfig, *this)
65 {
66 }
67
68
69 //-------------------------------------------------
70 // device_start - device-specific startup
71 //-------------------------------------------------
72
device_start()73 void c64_vizastar_cartridge_device::device_start()
74 {
75 }
76
77
78 //-------------------------------------------------
79 // c64_cd_r - cartridge data read
80 //-------------------------------------------------
81
c64_cd_r(offs_t offset,uint8_t data,int sphi2,int ba,int roml,int romh,int io1,int io2)82 uint8_t c64_vizastar_cartridge_device::c64_cd_r(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2)
83 {
84 if (!roml)
85 {
86 data = UNSCRAMBLE_DATA(m_roml[UNSCRAMBLE_ADDRESS(offset & 0xfff)]);
87 }
88
89 return data;
90 }
91