Examining circuit boards from the Space Shuttle's I/O Processor
Summary
An in-depth historical look at the Space Shuttle's I/O Processor, detailing the MIA network interface page and the PROM microcode page. It explains how Manchester encoding, barrel processing with MSC and BCE virtual processors, and fusible PROM were implemented for high reliability, with photos and architectural context. The article also compares IBM's 4 Pi page form factor to the Shuttle's larger 9-inch pages, illustrating design trade-offs in aerospace hardware.