1 // license:BSD-3-Clause
2 // copyright-holders:Curt Coder
3 /**********************************************************************
4
5 Structured Basic cartridge emulation
6
7 **********************************************************************/
8
9 #include "emu.h"
10 #include "structured_basic.h"
11
12
13
14 //**************************************************************************
15 // DEVICE DEFINITIONS
16 //**************************************************************************
17
18 DEFINE_DEVICE_TYPE(C64_STRUCTURED_BASIC, c64_structured_basic_cartridge_device, "c64_structured_basic", "C64 Structured Basic cartridge")
19
20
21
22 //**************************************************************************
23 // LIVE DEVICE
24 //**************************************************************************
25
26 //-------------------------------------------------
27 // c64_structured_basic_cartridge_device - constructor
28 //-------------------------------------------------
29
c64_structured_basic_cartridge_device(const machine_config & mconfig,const char * tag,device_t * owner,uint32_t clock)30 c64_structured_basic_cartridge_device::c64_structured_basic_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
31 device_t(mconfig, C64_STRUCTURED_BASIC, tag, owner, clock),
32 device_c64_expansion_card_interface(mconfig, *this),
33 m_bank(0)
34 {
35 }
36
37
38 //-------------------------------------------------
39 // device_start - device-specific startup
40 //-------------------------------------------------
41
device_start()42 void c64_structured_basic_cartridge_device::device_start()
43 {
44 // state saving
45 save_item(NAME(m_bank));
46 }
47
48
49 //-------------------------------------------------
50 // device_reset - device-specific reset
51 //-------------------------------------------------
52
device_reset()53 void c64_structured_basic_cartridge_device::device_reset()
54 {
55 m_exrom = 0;
56
57 m_bank = 0;
58 }
59
60
61 //-------------------------------------------------
62 // c64_cd_r - cartridge data read
63 //-------------------------------------------------
64
c64_cd_r(offs_t offset,uint8_t data,int sphi2,int ba,int roml,int romh,int io1,int io2)65 uint8_t c64_structured_basic_cartridge_device::c64_cd_r(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2)
66 {
67 if (!roml)
68 {
69 offs_t addr = (m_bank << 13) | (offset & 0x1fff);
70
71 data = m_roml[addr];
72 }
73
74 return data;
75 }
76
77
78 //-------------------------------------------------
79 // c64_cd_w - cartridge data write
80 //-------------------------------------------------
81
c64_cd_w(offs_t offset,uint8_t data,int sphi2,int ba,int roml,int romh,int io1,int io2)82 void c64_structured_basic_cartridge_device::c64_cd_w(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2)
83 {
84 if (!io1)
85 {
86 switch (data & 0x03)
87 {
88 case 0:
89 case 1:
90 m_exrom = 0;
91 m_bank = 0;
92 break;
93
94 case 2:
95 m_exrom = 0;
96 m_bank = 1;
97 break;
98
99 case 3:
100 m_exrom = 1;
101 m_bank = 0;
102 break;
103 }
104 }
105 }
106