openMSX
RomRType.cc
Go to the documentation of this file.
1// R-Type cartridges
2//
3// The address to change banks:
4// first 16kb: fixed at 0x0f or 0x17 (both have the same content)
5// second 16kb: 0x4000 - 0x7FFF (0x7000 and 0x7800 used)
6// bit 4 selects ROM chip,
7// if low bit 3-0 select page
8// high 2-0
9// Thanks to n_n for investigating this on a real cartridge.
10
11#include "RomRType.hh"
12#include "serialize.hh"
13
14namespace openmsx {
15
16RomRType::RomRType(const DeviceConfig& config, Rom&& rom_)
17 : Rom16kBBlocks(config, std::move(rom_))
18{
19 reset(EmuTime::dummy());
20}
21
22void RomRType::reset(EmuTime::param /*time*/)
23{
24 setUnmapped(0);
25 setRom(1, 0x17);
26 setRom(2, 0);
27 setUnmapped(3);
28}
29
30void RomRType::writeMem(word address, byte value, EmuTime::param /*time*/)
31{
32 if ((0x4000 <= address) && (address < 0x8000)) {
33 value &= (value & 0x10) ? 0x17 : 0x1F;
34 setRom(2, value);
35 }
36}
37
39{
40 if ((0x4000 <= address) && (address < 0x8000)) {
41 return nullptr;
42 } else {
43 return unmappedWrite.data();
44 }
45}
46
48
49} // namespace openmsx
#define REGISTER_MSXDEVICE(CLASS, NAME)
Definition MSXDevice.hh:354
static std::array< byte, 0x10000 > unmappedWrite
Definition MSXDevice.hh:305
void setUnmapped(unsigned region)
Select 'unmapped' memory for this region.
Definition RomBlocks.cc:92
void setRom(unsigned region, unsigned block)
Selects a block of the ROM image for reading in a certain region.
Definition RomBlocks.cc:104
void writeMem(word address, byte value, EmuTime::param time) override
Write a given byte to a given location at a certain time to this device.
Definition RomRType.cc:30
void reset(EmuTime::param time) override
This method is called on reset.
Definition RomRType.cc:22
RomRType(const DeviceConfig &config, Rom &&rom)
Definition RomRType.cc:16
byte * getWriteCacheLine(word address) const override
Test that the memory in the interval [start, start + CacheLine::SIZE) is cacheable for writing.
Definition RomRType.cc:38
This file implemented 3 utility functions:
Definition Autofire.cc:9
uint16_t word
16 bit unsigned integer
Definition openmsx.hh:29
STL namespace.