Oersted Ratings of DC300A and DC600 Tape Cartridges

From: Jerome H. Fine <jhfinepw4z_at_compsys.to>
Date: Wed Jan 8 09:00:00 2003

>Brian Chase wrote:

> > On Wed, 1 Jan 2003, Marvin Johnston wrote:
> > Wonderful, thanks much for the information!!! Due to financial concerns,
> > I am selling my IBM 5100 (sigh) on Ebay. Most of the tapes were DC300A,
> > and the extra ones I have are the DC600s. I am in the process of
> > duplicating the tapes, 1) so I can keep a set of the Patch and Games
> > tapes in case I can ever afford another one :), and 2) to make sure the
> > tapes are readable. Thanks again!
> If at all possible, it would be wise to store file images of these tapes
> on CDs or some other more modern storage format. I'm not sure exactly
> how one would go about doing this, but maybe someone on the list can
> offer some suggestions.
> -brian.

Jerome Fine replies:

I don't know if this information will help, but the DC600A tapes
that I used to use (I probably now have quite a few I can make
available) were placed in a TK25 tape drive made by DEC for
a PDP-11. I used then about 10 years ago to make backups
under RT-11. From what I learned over the years, they may
have used a QIC-24 (or something like that - my memory is
hazy) format. But I also suspect that the DEC tape drive
might have switched the BOT with the EOT - although that
might have been with the DC300 tapes that I used with an
11/23 system that had is own device driver.

In any case, making a backup copy of the data to be placed
on a TK25 tape drive using a DC600A media might not be
a great idea as opposed to making a copy of the hard drive
IF that possibility exists. There are always going to be trade
offs between using what seems to be a good suggestion as
opposed to what is even practical, let alone useful.

With regard to what a PDP-11 would place on a DC600A
tape, it would be far more useful to make a copy of the hard

However, since I don't have ANY experience at all with the
IBM 5100, my observations (based on how a PDP-11 would
use the information) are likely to be completely impractical.
However, just thought I might point out the experience I
have had from the DEC point of view.

Sincerely yours,

Jerome Fine
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Received on Wed Jan 08 2003 - 09:00:00 GMT

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