Replacing 8" drive with 3.5" drive on CP/M systems

From: Herb Johnson <>
Date: Sun Feb 6 14:11:29 2005

It seems a large chunk of this thread is also on "cctalk", as I'm
getting responses from that maillist. I currently only follow cctech,
but I posted a substantive reply in cctalk (I think) and I'm getting
private/public responses accordingly.

Briefly, I posted that I doubt that
a single density (FM) only system, such as the earliest CP/M systems,
could read and write successfully AND reliably to HD diskettes. Also, I
suggested the consequences of an old system owner who converted to this
"standard" and then found that noone else could read his disks. In
short, for the oldest of systems, there may be good reasons to continue
to use old, but well-known, formats, drives and disk media. My Web site
has pages of technical info and articles compiled from previous postings
on these technical issues.

I've recieved two comments to my post, which may also be on cctalk. One
suggested that 3.5" HD diskettes are convenient to find and buy. That
may be true but 1) convenience does nothing if HD disks won't work; and
2) you can still find DD 3.5" diskettes for sale via the Web - just not
at your local stores.

Another post said the Epson PX-8 had an external 3.5" drive. I checked
the Web, that drive is apparently using DSDD media. But it may be one of
a small number of 3.5" formats for CP/M that are worth considering as
"standard" I suppose. Better a known standard than a new, unknown one.

Herb JOhnson

Herbert R. Johnson, voice 609-771-1503, New Jersey USA
<a href=""> web site</a>
<a href=""> domain mirror</a>
     **MY "" site & email is EXPIRED **
my email address: herbjohnson ATT comcast DOTT net
if no reply, wait & try: hjohnson AAT retrotechnology DOTT com
"Herb's Stuff": old Mac, SGI, 8-inch floppy drives
S-100 IMSAI Altair computers, docs, by "Dr. S-100"
Received on Sun Feb 06 2005 - 14:11:29 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:37:36 BST