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Made an attempt to support memory maps other than the unexpanded default of 1kb.

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This commit is contained in:
Thomas Harte 2017-06-11 19:29:02 -04:00
parent 8116f85479
commit 6b602c74b7
2 changed files with 43 additions and 13 deletions
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47
Machines/ZX8081/ZX8081.cpp
View File

@ -20,7 +20,6 @@ namespace {
Machine::Machine() :
vsync_(false),
hsync_(false),
ram_(1024),
key_states_{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
tape_player_(ZX8081ClockRate) {
set_clock_rate(ZX8081ClockRate);
@ -86,10 +85,15 @@ int Machine::perform_machine_cycle(const CPU::Z80::MachineCycle &cycle) {
}
case CPU::Z80::BusOperation::Read:
if((address & 0xc000) == 0x0000) *cycle.value = rom_[address & (rom_.size() - 1)];
else if((address & 0x4000) == 0x4000) {
uint8_t value = ram_[address & 1023];
if(address&0x8000 && !(value & 0x40) && cycle.operation == CPU::Z80::BusOperation::ReadOpcode && !get_halt_line()) {
if(address < ram_base_) {
*cycle.value = rom_[address & rom_mask_];
} else {
uint8_t value = ram_[address & ram_mask_];
// If this is an M1 cycle reading from above the 32kb mark and HALT is not
// currently active, perform a video output and return a NOP. Otherwise,
// just return the value as read.
if(cycle.operation == CPU::Z80::BusOperation::ReadOpcode && address&0x8000 && !(value & 0x40) && !get_halt_line()) {
size_t char_address = (size_t)((refresh & 0xff00) | ((value & 0x3f) << 3) | line_counter_);
if((char_address & 0xc000) == 0x0000) {
uint8_t mask = (value & 0x80) ? 0x00 : 0xff;
@ -103,7 +107,9 @@ int Machine::perform_machine_cycle(const CPU::Z80::MachineCycle &cycle) {
break;
case CPU::Z80::BusOperation::Write:
if((address & 0x4000) == 0x4000) ram_[address & 1023] = *cycle.value;
if(address >= ram_base_) {
ram_[address & ram_mask_] = *cycle.value;
}
break;
default: break;
@ -139,14 +145,33 @@ void Machine::run_for_cycles(int number_of_cycles) {
void Machine::configure_as_target(const StaticAnalyser::Target &target) {
// TODO: pay attention to the target; it can't currently specify a ZX81
// so assume a ZX80 if we got here.
if(true) {
rom_ = zx80_rom_;
tape_trap_address_ = 0x220;
tape_return_address_ = 0x248;
} else {
if(target.zx8081.isZX81) {
rom_ = zx81_rom_;
tape_trap_address_ = 0x37c;
tape_return_address_ = 0x380;
} else {
rom_ = zx80_rom_;
tape_trap_address_ = 0x220;
tape_return_address_ = 0x248;
}
rom_mask_ = (uint16_t)(rom_.size() - 1);
switch(target.zx8081.memory_model) {
case StaticAnalyser::ZX8081MemoryModel::Unexpanded:
ram_.resize(1024);
ram_base_ = 16384;
ram_mask_ = 1023;
break;
case StaticAnalyser::ZX8081MemoryModel::SixteenKB:
ram_.resize(16384);
ram_base_ = 16384;
ram_mask_ = 16383;
break;
case StaticAnalyser::ZX8081MemoryModel::SixtyFourKB:
ram_.resize(65536);
ram_base_ = 8192;
ram_mask_ = 0xffff;
break;
}
if(target.tapes.size()) {

9
Machines/ZX8081/ZX8081.hpp
View File

@ -64,10 +64,15 @@ class Machine:
private:
std::shared_ptr<Video> video_;
std::vector<uint8_t> zx81_rom_, zx80_rom_, rom_;
std::vector<uint8_t> ram_;
std::vector<uint8_t> zx81_rom_, zx80_rom_;
uint16_t tape_trap_address_, tape_return_address_;
std::vector<uint8_t> ram_;
uint16_t ram_mask_, ram_base_;
std::vector<uint8_t> rom_;
uint16_t rom_mask_;
bool vsync_, hsync_;
int line_counter_;