It's presumably a Burroughs Certified Digital
Cassette.
I don't have the tech manual handy but ISTR (and
just confirmed by winding one through my audio
deck) that they are essentially C60s (i.e. 30
minutes/side), but with BOT/EOT holes and funky
flip-over or sliding write protect tabs, as well
as an off-centre notch in the top edge that
indicates the side. They're driven by the
wind/rewind motors, i.e. there's no capstan or
pressure roller.
I've got several boxes of them that I've been
meaning to archive "some day" and they seem to
still be in pretty good shape; the pressure pads
are made of felt, not the notorious disintegrating
foam rubber used in many audio cassettes.
They use two tracks, one for data and one for a
clock; I don't recall for sure whether they're
half or quarter tracks but I *think* they're
quarter tracks.
m
----- Original Message -----
From: "Evan Linwood" <evan.linwood at eastek.com.au>
To: "'General Discussion: On-Topic and Off-Topic
Posts'" <cctalk at classiccmp.org>
Sent: Monday, May 04, 2015 11:07 PM
Subject: RE: Cassette tape data recovery
Thanks Rik - actually I don't have the tape yet
& so don't know who the tape
manufacturer is.
The tape is effectively a boot tape & will have
been supplied by the
equipment manufacturer, so it's possible the
original manufacturer may not
be clear.
I'm hoping it's not as long as a std C60 or C90
(given the purpose),
shorter is definitely better :)
That's a good point about the gloves thx, as
I'll need to check inside the
housing as the machine appears to have been
outside for some time.
I'm imagining that old cassette tapes would need
to be 'baked' for some time
prior to recovery, as for 9 track tapes - hoping
to find out if anyone has
done this!
-----Original Message-----
From: cctalk
[mailto:cctalk-bounces at
classiccmp.org] On Behalf
Of Rik Bos
Sent: Monday, 4 May 2015 9:26 PM
To: 'General Discussion: On-Topic and Off-Topic
Posts'
Subject: RE: Cassette tape data recovery
-----Oorspronkelijk bericht-----
Van: cctalk
[mailto:cctalk-bounces at
classiccmp.org] Namens
Evan Linwood
Verzonden: maandag 4 mei 2015 10:48
Aan: cctalk at
classiccmp.org
Onderwerp: Cassette tape data recovery
I'm wondering if anyone on the list has much
experience recovering
data
from
old cassette tapes?
The tape to be read is a single cold-start tape
that was found sitting
the
B1900 system picked up by Noel Chiappa just
recently.
Given the tape's importance, I'd rather not fry
it or blow limited
opportunities by
attempting it myself!
- Evan
If you're talking about compact cassettes, like
C60/C90 or the data variant
like the Philips LGH 6003, they hold remarkable
good.
I've some original HP cassettes for the HP 9830A
which are from the early
seventies, all of them hold their data and are
working perfect.
The only thing is the cushion which presses the
tape to the head, sometimes
they used foam for those. You should replace
them .
If you have a normal cassette recorder (old one)
you could remove the head
and spool (slow speed) the tape some times to
see if it's spools smoothly.
If it doesn't spool smoothly, open op the tape
and replace the housing, that
should do the trick.
Copying will another problem because you will
need a drive with the same
head configuration, you could try to use an
audio card to digitize the tape
and store it for later use.
NB. Use gloves when you handle the tape, to
prevent dead spots on the tape.
-Rik