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mirror of https://github.com/TomHarte/CLK.git synced 2025-04-09 00:37:27 +00:00

Attempts actual performance of the state machine.

This commit is contained in:
Thomas Harte 2018-04-24 08:29:05 -07:00
parent 56d88f23ef
commit af61bbc3e2
4 changed files with 45 additions and 17 deletions

View File

@ -14,26 +14,28 @@ using namespace Apple;
void DiskII::set_control(Control control, bool on) {
printf("Set control %d %s\n", control, on ? "on" : "off");
// TODO: seeking, motor control.
}
void DiskII::set_mode(Mode mode) {
printf("Set mode %d\n", mode);
state_ = (state_ & ~0x08) | ((mode == Mode::Write) ? 0x8 : 0x0);
inputs_ = (inputs_ & ~0x08) | ((mode == Mode::Write) ? 0x2: 0x0);
}
void DiskII::select_drive(int drive) {
printf("Select drive %d\n", drive);
// TODO: select a drive.
}
void DiskII::set_data_register(uint8_t value) {
printf("Set data register (?)\n");
state_ |= 0x4;
inputs_ |= 0x1;
data_register_ = value;
}
uint8_t DiskII::get_shift_register() {
printf("Get shift register (?)\n");
state_ &= ~0x4;
printf("[%02x] ", shift_register_);
inputs_ &= ~0x1;
return shift_register_;
}
@ -51,20 +53,42 @@ void DiskII::run_for(const Cycles cycles) {
The bytes in the P6 ROM has the high four bits reversed compared to the BAPD charts, so you will have to reverse them after fetching the byte.
*/
// TODO: optimise the resting state.
uint8_t command = 0;
switch(command) {
case 0x0: shift_register_ = 0; break; // clear
case 0x9: shift_register_ = static_cast<uint8_t>(shift_register_ << 1); break; // shift left, bringing in a zero
case 0xd: shift_register_ = static_cast<uint8_t>((shift_register_ << 1) | 1); break; // shift left, bringing in a one
case 0xa:
shift_register_ = (shift_register_ >> 1) | (is_write_protected() ? 0x80 : 0x00);
break; // shift right, bringing in write protected status
case 0xb: shift_register_ = data_register_; break; // load
default: break;
int integer_cycles = cycles.as_int();
while(integer_cycles--) {
const int address =
(inputs_ << 2) |
((shift_register_&0x80) >> 6) |
((state_&0x2) >> 1) |
((state_&0x1) << 7) |
((state_&0x4) << 4) |
((state_&0x8) << 2);
// TODO: add pulse state in bit 4.
const uint8_t update = state_machine_[static_cast<std::size_t>(address)];
state_ = update >> 4;
state_ = ((state_ & 0x8) ? 0x1 : 0x0) | ((state_ & 0x4) ? 0x2 : 0x0) | ((state_ & 0x2) ? 0x4 : 0x0) | ((state_ & 0x1) ? 0x8 : 0x0);
uint8_t command = update & 0xf;
switch(command) {
case 0x0: shift_register_ = 0; break; // clear
case 0x9: shift_register_ = static_cast<uint8_t>(shift_register_ << 1); break; // shift left, bringing in a zero
case 0xd: shift_register_ = static_cast<uint8_t>((shift_register_ << 1) | 1); break; // shift left, bringing in a one
case 0xb: shift_register_ = data_register_; break; // load
case 0xa:
shift_register_ = (shift_register_ >> 1) | (is_write_protected() ? 0x80 : 0x00);
break; // shift right, bringing in write protected status
default: break;
}
}
}
bool DiskII::is_write_protected() {
return true;
}
void DiskII::set_state_machine(const std::vector<uint8_t> &state_machine) {
state_machine_ = state_machine;
// TODO: shuffle ordering here?
}

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@ -10,7 +10,9 @@
#define DiskII_hpp
#include "../../ClockReceiver/ClockReceiver.hpp"
#include <cstdint>
#include <vector>
namespace Apple {
@ -33,13 +35,16 @@ class DiskII {
uint8_t get_shift_register();
void run_for(const Cycles cycles);
void set_state_machine(const std::vector<uint8_t> &);
private:
uint8_t state_ = 0;
uint8_t inputs_ = 0;
uint8_t shift_register_ = 0;
uint8_t data_register_ = 0;
bool is_write_protected();
std::vector<uint8_t> state_machine_;
};
}

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@ -18,7 +18,7 @@ DiskIICard::DiskIICard(const ROMMachine::ROMFetcher &rom_fetcher, bool is_16_sec
"state-machine.rom"
});
boot_ = std::move(*roms[0]);
state_machine_ = std::move(*roms[1]);
diskii_.set_state_machine(*roms[1]);
}
void DiskIICard::perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
@ -61,5 +61,5 @@ void DiskIICard::perform_bus_operation(CPU::MOS6502::BusOperation operation, uin
}
void DiskIICard::run_for(Cycles cycles, int stretches) {
diskii_.run_for(cycles);
diskii_.run_for(Cycles(cycles.as_int() * 2));
}

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@ -26,7 +26,6 @@ class DiskIICard: public Card {
private:
std::vector<uint8_t> boot_;
std::vector<uint8_t> state_machine_;
Apple::DiskII diskii_;
};