5 May
2015
5 May
'15
3:46 a.m.
Ah I'd imagined them to be short - but not so (you were spot on Rik).
I didn't expect they'd have BOT/EOT holes (then again I've only dealt with
data cassettes in the context of some early micros)
Interesting that there's no capstan/pressure roller, I haven't seen a
cassette drive like that before.
I'll ask around further re the half/quarter track recording, if they're
quarter track it would be necessary to flip sides at the half way mark?
Thanks for the help!
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Mike Stein
Sent: Tuesday, 5 May 2015 2:51 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Cassette tape data recovery
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