OXYGENHUB
◆ main openmsx / src / MSXKanji.cc
3.6 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
1 
#include "MSXKanji.hh"
2
3 
#include "MSXException.hh"
4 
#include "TclObject.hh"
5 
#include "serialize.hh"
6
7 
#include "one_of.hh"
8
9 
namespace openmsx {
10
11 
MSXKanji::MSXKanji(DeviceConfig& config)
12 
	: MSXDevice(config)
13 
	, rom(getName(), "Kanji ROM", config)
14 
	, highAddressMask(config.getChildData("type", {}) == "hangul" ? 0x7F : 0x3F)
15 
{
16 
	auto level2ViaStr = config.getChildData("level_2_via", "read"); // default 'read' for bw compat
17 
	if (level2ViaStr == "read") {
18 
		level2Via = Level2Via::Read;
19 
		portMask = 3;
20 
	} else if (level2ViaStr == "write") {
21 
		level2Via = Level2Via::Write;
22 
		portMask = 3;
23 
	} else if (level2ViaStr == "interlocked_write_read") {
24 
		level2Via = Level2Via::InterlockedWriteRead;
25 
		portMask = 3;
26 
	} else if (level2ViaStr == "only_level_1") {
27 
		level2Via = Level2Via::Read;
28 
		portMask = 1; // implemented by redirecting level2 ports to level1
29 
	} else {
30 
		throw MSXException("MSXKanji: invalid value for 'level_2_via'");
31 
	}
32
33 
	auto size = rom.size();
34 
	if (size != one_of(0x20000u, 0x40000u)) {
35 
		throw MSXException("MSXKanji: wrong kanji ROM, it should be either 128kB or 256kB.");
36 
	}
37 
	if ((highAddressMask == 0x7F) && (size != 0x40000)) {
38 
		throw MSXException("MSXKanji: for hangul type, the font ROM must be 256kB.");
39 
	}
40
41 
	reset(EmuTime::dummy());
42 
}
43
44 
void MSXKanji::reset(EmuTime /*time*/)
45 
{
46 
	adr = 0; // TODO check inital value
47 
	writeLevel = 0;
48 
}
49
50 
void MSXKanji::writeIO(uint16_t port, uint8_t value, EmuTime /*time*/)
51 
{
52 
	port &= portMask;
53 
	writeLevel = (port & 2) ? 1 : 0;
54
55 
	switch (port & 1) {
56 
	case 0:
57 
		adr = (adr & 0x3f800) | ((value & 0x3f) << 5); // 6 bit column
58 
		break;
59 
	case 1:
60 
		adr = (adr & 0x007e0) | ((value & highAddressMask) << 11); // 6 or 7 (for 'hangul') bit row
61 
		break;
62 
	}
63 
	// note: write to either row/column resets the counter
64 
}
65
66 
MSXKanji::ReadImplResult MSXKanji::readImpl(uint16_t port) const
67 
{
68 
	uint8_t readLevel = (port & portMask & 2) ? 1 : 0;
69
70 
	unsigned address = 0;
71 
	switch (level2Via) {
72 
	case Level2Via::Read:
73 
		address = adr | (readLevel << 17);
74 
		break;
75 
	case Level2Via::InterlockedWriteRead:
76 
		if (readLevel != writeLevel) return {.valid = false, .value = 0xFF};
77 
		[[fallthrough]];
78 
	case Level2Via::Write:
79 
		address = adr | (writeLevel << 17);
80 
		break;
81 
	}
82
83 
	auto value = (address < rom.size()) ? rom[address] : uint8_t(0xff);
84 
	return {.valid = true, .value = value};
85 
}
86
87 
uint8_t MSXKanji::peekIO(uint16_t port, EmuTime /*time*/) const
88 
{
89 
	return readImpl(port).value;
90 
}
91
92 
uint8_t MSXKanji::readIO(uint16_t port, EmuTime /*time*/)
93 
{
94 
	auto [valid, value] = readImpl(port);
95 
	if (valid) {
96 
		adr = (adr & ~0x1f) | ((adr + 1) & 0x1f);
97 
	}
98 
	return value;
99 
}
100
101 
void MSXKanji::getExtraDeviceInfo(TclObject& result) const
102 
{
103 
	rom.getInfo(result);
104 
}
105
106 
// version 1 : initial version
107 
// version 2 : replaced adr1/adr2 with a single shared adr, added writeLevel
108 
template<typename Archive>
109 
void MSXKanji::serialize(Archive& ar, unsigned version)
110 
{
111 
	ar.template serializeBase<MSXDevice>(*this);
112 
	if (ar.versionBelow(version, 2)) {
113 
		assert(Archive::IS_LOADER);
114 
		ar.serialize("adr1", adr);
115 
		//ar.serialize("adr2", adr); // ignored
116 
		writeLevel = 0;
117 
	} else {
118 
		ar.serialize("adr",        adr,
119 
		             "writeLevel", writeLevel);
120 
	}
121 
}
122 
INSTANTIATE_SERIALIZE_METHODS(MSXKanji);
123 
REGISTER_MSXDEVICE(MSXKanji, "Kanji");
124
125 
/*
126 
This really works!
127
128 
10 DIM A(32)
129 
20 FOR I=0 TO 4095
130 
30 OUT &HD8, I MOD 64: OUT &HD9, I\64
131 
40 FOR J=0 TO 31: A(J)=INP(&HD9): NEXT
132 
50 FOR J=0 TO 7
133 
60 PRINT RIGHT$("0000000"+BIN$(A(J)), 8);
134 
70 PRINT RIGHT$("0000000"+BIN$(A(J+8)), 8)
135 
80 NEXT
136 
90 FOR J=16 TO 23
137 
100 PRINT RIGHT$("0000000"+BIN$(A(J)), 8);
138 
110 PRINT RIGHT$("0000000"+BIN$(A(J+8)), 8)
139 
120 NEXT
140 
130 PRINT
141 
140 NEXT
142 
*/
143
144 
} // namespace openmsx