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Switches to a less easy-to-confuse storage arrangement for MSX memory slots.

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This commit is contained in:
Thomas Harte 2017-12-11 21:09:53 -05:00
parent 798cdba979
commit afcdd64d5e
1 changed files with 23 additions and 14 deletions
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37
Machines/MSX/MSX.cpp
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@ -86,16 +86,17 @@ class ConcreteMachine:
// TODO: should clear other page 1 pointers, should allow for paging cartridges, etc.
size_t base = segment.start_address >> 14;
for(size_t c = 0; c < cartridge_.size(); c += 16384) {
slot_read_pointers_[1][(c >> 14) + base] = cartridge_.data() + c;
memory_slots_[1].read_pointers[(c >> 14) + base] = cartridge_.data() + c;
}
}
return true;
}
void page_memory(uint8_t value) {
// printf("Page: %02x\n", value);
for(size_t c = 0; c < 4; ++c) {
read_pointers_[c] = slot_read_pointers_[value & 3][c];
write_pointers_[c] = slot_write_pointers_[value & 3][c];
read_pointers_[c] = memory_slots_[value & 3].read_pointers[c];
write_pointers_[c] = memory_slots_[value & 3].write_pointers[c];
value >>= 2;
}
}
@ -167,6 +168,10 @@ class ConcreteMachine:
case 0xaa: case 0xab:
i8255_.set_register(address, *cycle.value);
break;
case 0xfc: case 0xfd: case 0xfe: case 0xff:
// printf("RAM banking %02x: %02x\n", port, *cycle.value);
break;
}
} break;
@ -202,22 +207,24 @@ class ConcreteMachine:
basic_.resize(16384);
main_ = std::move(*roms[1]);
main_.resize(16384);
main_.resize(32768);
for(size_t c = 0; c < 4; ++c) {
for(size_t slot = 0; slot < 3; ++slot) {
slot_read_pointers_[slot][c] = unpopulated_;
slot_write_pointers_[slot][c] = scratch_;
memory_slots_[slot].read_pointers[c] = unpopulated_;
memory_slots_[slot].write_pointers[c] = scratch_;
}
slot_read_pointers_[3][c] =
slot_write_pointers_[3][c] = &ram_[c * 16384];
memory_slots_[3].read_pointers[c] =
memory_slots_[3].write_pointers[c] = &ram_[c * 16384];
}
slot_read_pointers_[0][0] = main_.data();
slot_read_pointers_[0][1] = basic_.data();
memory_slots_[0].read_pointers[0] = main_.data();
memory_slots_[0].read_pointers[1] = &main_[16384];
for(size_t c = 0; c < 4; ++c) {
read_pointers_[c] = slot_read_pointers_[0][c];
write_pointers_[c] = slot_write_pointers_[0][c];
read_pointers_[c] = memory_slots_[0].read_pointers[c];
write_pointers_[c] = memory_slots_[0].write_pointers[c];
}
return true;
@ -287,8 +294,10 @@ class ConcreteMachine:
uint8_t *read_pointers_[4];
uint8_t *write_pointers_[4];
uint8_t *slot_read_pointers_[4][4];
uint8_t *slot_write_pointers_[4][4];
struct MemorySlots {
uint8_t *read_pointers[4];
uint8_t *write_pointers[4];
} memory_slots_[4];
uint8_t ram_[65536];
uint8_t scratch_[16384];