6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2025-01-26 15:32:04 +00:00
Code Issues Projects Releases Wiki Activity

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

Browse Source 
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.
This commit is contained in:
Ryan Carsten Schmidt 2023-11-29 05:50:20 -06:00 committed by GitHub
parent b07cc5c2ec
commit 3293ab48ce
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 8 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
Components/DiskII/DiskII.cpp
View File

@ -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?