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Eliminates 'data' register as it doesn't exist; rejigs state machine command set.

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This commit is contained in:
Thomas Harte 2018-05-16 22:09:59 -04:00
parent 1aba9f807e
commit 8a031b1137
2 changed files with 9 additions and 6 deletions
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14
Components/DiskII/DiskII.cpp
View File

@ -84,7 +84,7 @@ void DiskII::select_drive(int drive) {
void DiskII::set_data_register(uint8_t value) {
// printf("Set data register (?)\n");
inputs_ |= input_command;
data_register_ = value;
// shift_register_ = value;
set_controller_can_sleep();
}
@ -106,15 +106,20 @@ void DiskII::run_for(const Cycles cycles) {
inputs_ |= input_flux;
state_ = state_machine_[static_cast<std::size_t>(address)];
switch(state_ & 0xf) {
case 0x0: shift_register_ = 0; break; // clear
default: shift_register_ = 0; break; // clear
case 0x8: break; // nop
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 right, bringing in write protected status
shift_register_ = (shift_register_ >> 1) | (is_write_protected() ? 0x80 : 0x00);
break;
default: break;
case 0xb:
// load data register from data bus...
printf("TODO\n");
// shift_register_ = data_register_;
break; // load
}
// TODO: surely there's a less heavyweight solution than this?
@ -139,7 +144,6 @@ void DiskII::set_controller_can_sleep() {
}
bool DiskII::is_write_protected() {
return true;
return !!(stepper_mask_ & 2) | drives_[active_drive_].get_is_read_only();
}

1
Components/DiskII/DiskII.hpp
View File

@ -65,7 +65,6 @@ class DiskII:
uint8_t state_ = 0;
uint8_t inputs_ = 0;
uint8_t shift_register_ = 0;
uint8_t data_register_ = 0;
int stepper_mask_ = 0;
int stepper_position_ = 0;