HP 9895A Part 2: Epic Controller Board Repair (and a transparent chip surprise)
We restore more HP 9895A dual 8" diskette HP-IB drives, but these will be way more challenging. We'll need a full on logic analyzer assisted repair to debug a really, really nasty fault. It's a long video, but don't miss the intermission where Master Ken inspects a transparent silicon-on-sapphire chip!
Many thanks to HP enthusiast Craig Ruff for the ROM dump and disassembly.
8" Floppy Playlist: • 8" Floppy Diskette Drives
HP 9825 Playlist: • HP 9825 Repair
Ken's Silicon-on-Sapphire chip blog post: http://www.righto.com/2023/12/HP-sili...
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