1 /*
2 * KCemu -- The emulator for the KC85 homecomputer series and much more.
3 * Copyright (C) 1997-2010 Torsten Paul
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23
24 #include "kc/system.h"
25
26 #include "kc/kc.h"
27 #include "kc/z80.h"
28 #include "kc/disk_io.h"
29
30 #include "libdbg/dbg.h"
31
FloppyIO(void)32 FloppyIO::FloppyIO(void)
33 {
34 _bit[0] = _bit[1] = _bit[2] = _bit[3] = 0;
35 }
36
~FloppyIO(void)37 FloppyIO::~FloppyIO(void)
38 {
39 }
40
41 /*
42 * BIT 7 6 5 4 3 2 1 0
43 * | | | |
44 * | | | - Freigabe des Prozessors
45 * | | --- Setzen des Prozessors in Dauer-RESET
46 * | ----- Ausgabe RESET-Impuls
47 * ------- Ausgabe NMI-Impuls
48 */
49 byte_t
in(word_t addr)50 FloppyIO::in(word_t addr)
51 {
52 byte_t val = _val;
53
54 DBG(2, form("KCemu/FloppyIO/in",
55 "FloppyIO::in(): addr = %04x, val = %02x\n",
56 addr, val));
57
58 return val;
59 }
60
61 void
out(word_t addr,byte_t val)62 FloppyIO::out(word_t addr, byte_t val)
63 {
64 int a;
65
66 DBG(2, form("KCemu/FloppyIO/out",
67 "FloppyIO::out(): addr = %04x, val = %02x\n",
68 addr, val));
69
70 for (a = 0;a < 3;a++)
71 {
72 if (val & (1 << a))
73 {
74 _bit[a] = true;
75 /*
76 * Hmm, the manual says activation is done after a 1/0
77 * transition but this doen't really works :-(
78 */
79 activate(a);
80 }
81 else
82 {
83 _bit[a] = false;
84 }
85 }
86
87 _val = val;
88 }
89
90 void
activate(int bit_nr)91 FloppyIO::activate(int bit_nr)
92 {
93 switch (bit_nr)
94 {
95 case 0:
96 DBG(2, form("KCemu/FloppyIO/activate",
97 "FloppyIO::activate(): bit = %d, start processor\n",
98 bit_nr));
99 z80->start_floppy_cpu();
100 break;
101 case 1:
102 DBG(2, form("KCemu/FloppyIO/activate",
103 "FloppyIO::activate(): bit = %d, halt processor\n",
104 bit_nr));
105 z80->halt_floppy_cpu(false);
106 break;
107 case 2:
108 DBG(2, form("KCemu/FloppyIO/activate",
109 "FloppyIO::activate(): bit = %d, trigger RESET\n",
110 bit_nr));
111 break;
112 case 3:
113 DBG(2, form("KCemu/FloppyIO/activate",
114 "FloppyIO::activate(): bit = %d, trigger NMI\n",
115 bit_nr));
116 break;
117 default:
118 DBG(0, form("KCemu/warning",
119 "FloppyIO::activate(): bit = %d ???\n",
120 bit_nr));
121 break;
122 }
123 }
124