CDC 9429 Floppy maintenance manual

[tony duell]

> > Actually, many lines of drives, such as the Tandon TM100 have the
> > same circuitry for both the 48tpi and 96tpi variants. (and the
> > TM100-4M at 100tpi)
> 
> One of the things that endears to me those pieces of garbage is that

They are considerably better than the Shugart drives with the plastic disk 
with a spiral groove for the head positioner....

> they apparently changed PCB designs according to what parts they had on
> hand.  I've got at least three different versions of the TM-100 PCBs,
> depending on the head stepper used (4 wire/6 wire).  Some were better
> than others.

HP used the TM100 in some of their machines. Oddly, the PCB is electrically
identical to the normal Tandon one (even down to having jumper options that
are never used in HP machines AFAIK) and has the same layout but is built like
an HP board (entirely gold plated) and many of the ICs have 1820-xxxx numbers.

-tony