Paleontological data fossilized on IBM 8" floppies

Chuck Guzis cclist at
Sun Nov 3 16:29:59 CST 2019

On 11/3/19 1:47 PM, Lyle Bickley wrote:
> Antoine,
> It's not too difficult to read most "standard" 8" floppies (DEC RX02's being
> the exception). The board below deals with both signal routing between 8" and
> standard PC floppy interfaces and the "TG43" signal required by most 8" drives:

I believe that the TG43 signal (if required; some drives generate it
internally) is only used for writing (reduced write current).

You can probably get by just fine if you've got the connectors handy by
wiring up your own cable.  Micro Solutions, back in the day sold a small
adapter PCB with a 34-conductor PCB edge connector and a 50 conductor
header for connection to a SA-800 style cable.

This assumes that your 8" drive follows the SA-800 pinout convention.
Some early drives (e.g. Calcomp, (IBM) do not.

Same for the power connections.   Many use the Amp (now TE) Mate-N-Lok
connector PIN 1-380999-0, but by no means all.   AC connections, if
needed are subject to the usual 50/60 Hz and line voltage considerations.

I use older open-frame linear power supplies, but the +24V/+5V
requirement is a lot easier to satisfy today, since inexpensive
multi-amp SMPSUs are available (generally less than $15).  Even dual-
and triple- output PSUs are available for around $20 that should supply
more than enough current.

Hope this helps,

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