4 ms·
Did not fast loaders for the drive put a small program on the disk drive?
by ecpottinger 5y ago
Did not fast loaders for the drive put a small program on the disk drive?
- tenebrisalietum 5y agoThey did, but the CPU still has to manually manipulate the ATN, DATA, and CLK pins. There's no I/O controller, just two "Complex Interface Adapter" which each have 8 I/O ports, readable/writeable by the CPU using standard LDA/STA, etc. instructions. (The CIAs also have a timer and can generate IRQs). IIRC 3 bits from CIA #2 can set/read each pin state. The CIA won't do anything to those on its own at all. I think there were plans to use something like IEEE-488 or GPIB but scrapped due to cost. So you can definitely write a program to implement a faster protocol than the one in the Kernal/1541 ROM (e.g use DATA and CLK as data lines and use ATN to sync, doubling transfer rate), but the CPU will still need to be 100% utilized in the (shorter) transmission.