[cctalk] Looking for information on Data General 602X magtape drive

[Bjoren Davis via cctalk]

Hello CCtalk,

I recently bought the mortal remains of a Data General 602X magtape 
drive on craigslist.

Apparently it had been stored outside.  When I got it it had mudwasp 
nests and mud all over it and everything that could rust had.

When it was decomissioned it was just cut out, so it's missing its 
chassis, hinges, controller board, power supplies, vacuum blower, vacuum 
pressure limit switches, etc. The cables to the heads are just cut (no 
connectors).

But boy does it look cool, and it *does* have all three of its transport 
motors and its console PCB.

There's very little identifying information on the drive.  The front of 
the drive has a label "9 TRACK 800 BPI".  The console PCB says 
"COPYRIGHT © 1973 BY DATA GENERAL CORP" "CONTROL BOARD FOR 75 I.P.S. 
DRIVE   DGC NOVA 107-000275-17 /16" and has a sticker on the back 
"DRAWING NO.  REV.      005-005-525-02 005-001-743-11".  The date codes 
on the few chips I can read place it from 1976.  I think all of this 
adds up to this being a model 6021 or 6023.

I've been slowly disassembling, cleaning, and repairing it.  The DG 
documentation at bitsavers is really good, but, sadly, the schematics 
are not available there.

Does anyone have such schematics?  I'm especially interested in the 
analog portion that connects to the heads, the connection to the BOT/EOT 
sensor, and a schematic for the console board I actually do have.

My goal is to replace all of the missing controller parts with some SOC 
boards (e.g., a Teensy 4.1), ultimately to be able to use this drive to 
read and write tapes.  I'd love to reuse the console board as it is.  
I've already replaced the vacuum blower with a $30 Bosch vacuum cleaner 
I also bought on craigslist.

Thanks.

--Bjoren