Piers reaches the end of his tether

This week I try to get my new Commodore IEEE-488 drive diagnostics ROM working in my 8050 drive. Try being the operative word.

This leads to a deep dive into the schematics and identification of two schematic errors, and the use of unusual 2364s in the (or, at least my) 8050.

This is the correct schematic: http://www.zimmers.net/anonftp/pub/cbm/schematics/drives/old/8050/8050-25.gif
This is the incorect schematic: http://www.zimmers.net/anonftp/pub/cbm/schematics/drives/old/8050/8050_schematics.pdf

You can find the diagnostics ROM here: https://github.com/piersfinlayson/cbm-ieee-disk-diag-rom

Timestamps

00:00 Introduction
02:44 First power on
04:23 Testing the diags ROM
05:56 Exploring the diags ROM
14:37 Diving into the schematics
29:52 The drive works, anyway
32:09 Final thoughts