<was being built. The fasted part was 5MHz. Therefore it would have <probably had to run at 3MHz, and it would have been a _lot_ slower than <doing it on the 6MHz 80286 CPU. Of course with a proper DMA controller Nope, it was dealing with the 64k block limit and mapping. Speed isn't a problem for the DMA controller as it only has to keep up with the device! At that time the 8237 was still faster than most disks. Now the keyboard interface is an 8042(or 8742) chip, it's easy to crank the code of of them and disassemble it. the 8048 (the 8042 is a slave) instruction set is all one and two byte opcodes and pretty simple. Allison