The goal is to emulate behaviour of IBM XT PC host interface comprised of logic ICs and to support virtually all of existent XT keyboards in the result. I hope so at least. You can get firmware and ...

1 KiB ROM is used for font Two KR580VV55A (Intel 8255A) PPIs. One is used for keyboard and cassette I/O, another one for the extension port Normally the computer consisted of 2 or 3 PCBs - the ...

The 8255A Programmable Peripheral Interface (PPI) implements a general-purpose I/O interface to connect peripheral equipment to a microcomputer system bus. The core’s functional configuration is ...