Cassette tape data recovery

Evan Linwood evan.linwood at
Tue May 5 05:46:17 CDT 2015

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] 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

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


----- Original Message -----
From: "Evan Linwood" <evan.linwood at>
To: "'General Discussion: On-Topic and Off-Topic Posts'"
<cctalk at>
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] 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] Namens
>> Evan Linwood
>> Verzonden: maandag 4 mei 2015 10:48
>> Aan: cctalk at
>> 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

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