1 /*
2 * vic20ieeevia1.c - IEEE488 interface VIA1 emulation in the VIC-1112.
3 *
4 * Written by
5 * Andre Fachat <a.fachat@physik.tu-chemnitz.de>
6 * Andreas Boose <viceteam@t-online.de>
7 *
8 * This file is part of VICE, the Versatile Commodore Emulator.
9 * See README for copyright notice.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24 * 02111-1307 USA.
25 *
26 */
27
28 #include "vice.h"
29
30 #include <stdio.h>
31
32 #include "drive.h"
33 #include "interrupt.h"
34 #include "lib.h"
35 #include "maincpu.h"
36 #include "parallel.h"
37 #include "types.h"
38 #include "via.h"
39 #include "vic20.h"
40 #include "vic20ieeevia.h"
41
42
ieeevia1_dump(void)43 int ieeevia1_dump(void)
44 {
45 return viacore_dump(machine_context.ieeevia1);
46 }
47
ieeevia1_store(uint16_t addr,uint8_t data)48 void ieeevia1_store(uint16_t addr, uint8_t data)
49 {
50 viacore_store(machine_context.ieeevia1, addr, data);
51 }
52
ieeevia1_read(uint16_t addr)53 uint8_t ieeevia1_read(uint16_t addr)
54 {
55 return viacore_read(machine_context.ieeevia1, addr);
56 }
57
ieeevia1_peek(uint16_t addr)58 uint8_t ieeevia1_peek(uint16_t addr)
59 {
60 return viacore_peek(machine_context.ieeevia1, addr);
61 }
62
set_ca2(via_context_t * via_context,int state)63 static void set_ca2(via_context_t *via_context, int state)
64 {
65 }
66
set_cb2(via_context_t * via_context,int state)67 static void set_cb2(via_context_t *via_context, int state)
68 {
69 }
70
set_int(via_context_t * via_context,unsigned int int_num,int value,CLOCK rclk)71 static void set_int(via_context_t *via_context, unsigned int int_num, int value, CLOCK rclk)
72 {
73 interrupt_set_irq(maincpu_int_status, int_num, value, rclk);
74 }
75
restore_int(via_context_t * via_context,unsigned int int_num,int value)76 static void restore_int(via_context_t *via_context, unsigned int int_num, int value)
77 {
78 interrupt_restore_irq(maincpu_int_status, int_num, value);
79 }
80
undump_acr(via_context_t * via_context,uint8_t byte)81 static void undump_acr(via_context_t *via_context, uint8_t byte)
82 {
83 }
84
store_acr(via_context_t * via_context,uint8_t byte)85 static void store_acr(via_context_t *via_context, uint8_t byte)
86 {
87 }
88
store_sr(via_context_t * via_context,uint8_t byte)89 static void store_sr(via_context_t *via_context, uint8_t byte)
90 {
91 }
92
store_t2l(via_context_t * via_context,uint8_t byte)93 static void store_t2l(via_context_t *via_context, uint8_t byte)
94 {
95 }
96
undump_pra(via_context_t * via_context,uint8_t byte)97 static void undump_pra(via_context_t *via_context, uint8_t byte)
98 {
99 }
100
store_pra(via_context_t * via_context,uint8_t byte,uint8_t myoldpa,uint16_t addr)101 static void store_pra(via_context_t *via_context, uint8_t byte, uint8_t myoldpa,
102 uint16_t addr)
103 {
104 }
105
undump_prb(via_context_t * via_context,uint8_t byte)106 static void undump_prb(via_context_t *via_context, uint8_t byte)
107 {
108 parallel_cpu_set_dav((uint8_t)(!(byte & 0x01)));
109 parallel_cpu_set_nrfd((uint8_t)(!(byte & 0x02)));
110 parallel_cpu_set_ndac((uint8_t)(!(byte & 0x04)));
111 }
112
store_prb(via_context_t * via_context,uint8_t byte,uint8_t myoldpb,uint16_t addr)113 static void store_prb(via_context_t *via_context, uint8_t byte, uint8_t myoldpb,
114 uint16_t addr)
115 {
116 parallel_cpu_set_dav((uint8_t)(!(byte & 0x01)));
117 parallel_cpu_set_nrfd((uint8_t)(!(byte & 0x02)));
118 parallel_cpu_set_ndac((uint8_t)(!(byte & 0x04)));
119 }
120
undump_pcr(via_context_t * via_context,uint8_t byte)121 static void undump_pcr(via_context_t *via_context, uint8_t byte)
122 {
123 }
124
reset(via_context_t * via_context)125 static void reset(via_context_t *via_context)
126 {
127 parallel_cpu_set_dav(0);
128 parallel_cpu_set_nrfd(0);
129 parallel_cpu_set_ndac(0);
130 }
131
store_pcr(via_context_t * via_context,uint8_t byte,uint16_t addr)132 static uint8_t store_pcr(via_context_t *via_context, uint8_t byte, uint16_t addr)
133 {
134 return byte;
135 }
136
read_pra(via_context_t * via_context,uint16_t addr)137 static uint8_t read_pra(via_context_t *via_context, uint16_t addr)
138 {
139 return 0xff;
140 }
141
read_prb(via_context_t * via_context)142 static uint8_t read_prb(via_context_t *via_context)
143 {
144 uint8_t byte;
145
146 drive_cpu_execute_all(maincpu_clk);
147
148 byte = 255
149 - (parallel_atn ? 0x80 : 0)
150 - (parallel_ndac ? 0x40 : 0)
151 - (parallel_nrfd ? 0x20 : 0)
152 - (parallel_dav ? 0x10 : 0)
153 - (parallel_eoi ? 0x08 : 0);
154
155 /* none of the load changes output register value -> std. masking */
156 byte = ((byte & ~(via_context->via[VIA_DDRB]))
157 | (via_context->via[VIA_PRB] & via_context->via[VIA_DDRB]));
158 return byte;
159 }
160
ieeevia1_init(via_context_t * via_context)161 void ieeevia1_init(via_context_t *via_context)
162 {
163 viacore_init(machine_context.ieeevia1, maincpu_alarm_context,
164 maincpu_int_status, maincpu_clk_guard);
165 }
166
vic20ieeevia1_setup_context(machine_context_t * machinecontext)167 void vic20ieeevia1_setup_context(machine_context_t *machinecontext)
168 {
169 via_context_t *via;
170
171 machinecontext->ieeevia1 = lib_malloc(sizeof(via_context_t));
172 via = machinecontext->ieeevia1;
173
174 via->prv = NULL;
175 via->context = NULL;
176
177 via->rmw_flag = &maincpu_rmw_flag;
178 via->clk_ptr = &maincpu_clk;
179
180 via->myname = lib_msprintf("IeeeVia1");
181 via->my_module_name = lib_msprintf("IeeeVia1");
182
183 viacore_setup_context(via);
184
185 via->write_offset = 0;
186
187 via->irq_line = IK_IRQ;
188
189 via->undump_pra = undump_pra;
190 via->undump_prb = undump_prb;
191 via->undump_pcr = undump_pcr;
192 via->undump_acr = undump_acr;
193 via->store_pra = store_pra;
194 via->store_prb = store_prb;
195 via->store_pcr = store_pcr;
196 via->store_acr = store_acr;
197 via->store_sr = store_sr;
198 via->store_t2l = store_t2l;
199 via->read_pra = read_pra;
200 via->read_prb = read_prb;
201 via->set_int = set_int;
202 via->restore_int = restore_int;
203 via->set_ca2 = set_ca2;
204 via->set_cb2 = set_cb2;
205 via->reset = reset;
206 }
207