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Handle C, E, F operations in Disk II state machine

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This shouldn't matter since these operations are not requested by the
state machine but this is what those operations should do according to
Understanding the Apple II, Table 9.3, page 9-15.
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Ryan Carsten Schmidt 2023-11-29 05:50:20 -06:00 committed by GitHub
parent b07cc5c2ec
commit 3293ab48ce
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1 changed files with 8 additions and 3 deletions
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11
Components/DiskII/DiskII.cpp
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@ -91,12 +91,15 @@ void DiskII::run_for(const Cycles cycles) {
state_ = state_machine_[size_t(address)];
switch(state_ & 0xf) {
default: shift_register_ = 0; break; // clear
case 0x8: break; // nop
case 0x8:
case 0xc: break; // nop
case 0x9: shift_register_ = uint8_t(shift_register_ << 1); break; // shift left, bringing in a zero
case 0xd: shift_register_ = uint8_t((shift_register_ << 1) | 1); break; // shift left, bringing in a one
case 0xa: // shift right, bringing in write protected status
case 0xa:
case 0xe: // shift right, bringing in write protected status
shift_register_ = (shift_register_ >> 1) | (is_write_protected() ? 0x80 : 0x00);
// If the controller is in the sense write protect loop but the register will never change,
@ -108,7 +111,9 @@ void DiskII::run_for(const Cycles cycles) {
return;
}
break;
case 0xb: shift_register_ = data_input_; break; // load data register from data bus
case 0xb:
case 0xf: shift_register_ = data_input_; break; // load data register from data bus
}
// Currently writing?