Firing up the pdt11

Chris Zach cz at
Sun Oct 11 19:11:26 CDT 2020

I'm back to working on the PDT11/150 again, the bottom floppy is weird: 
It doesn't read rx01 disks, period. Top one is fine. So I tried swapping 
all of the connectors on the control board so the top one was PD1: and 
the bottom was PD0: Sure enough the top drive works fine as PD1: and 
bottom is still dead so it's a drive issue.

Pull the drive, put in a spare, button it up, and sure enough it still 
doesn't work. Any ideas?

Also I recall my MiniMinc/150 (which is in parts in my shed) had EIS and 
FIS, but this one only reports FIS. Did DEC make pdp11/03 expansion 
chips that only had FIS?


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