Symbolics MCD-405 tape drive / Georgens Industries

Al Kossow aek at
Thu Oct 8 15:49:04 CDT 2015

On 10/8/15 11:15 AM, Al Kossow wrote:
> Does anyone have a loose 3M/Georgens MCD-405 tape drive they could take board pictures
> and firmware dumps from, or any of the other MCD-40 series tape drives? I'm trying to
> figure out how similar it is to the one in the Apple 40mb tape drive.

looks like Brad went down this rabbit hole 10 years ago

List:       classiccmp
Subject:    QIC-100 SCSI tape drive?
From:       Brad Parker <brad () heeltoe ! com>
Date:       2004-03-29 15:01:57
Message-ID: 200403291501.i2TF1vX09756 () mwave ! heeltoe ! com
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Anyone have a QIC-100 SCSI tape drive drive?  Or know where to get one?

Seems like there was a brief window when such a thing existed, but I
can't seem to find any evidence on the web.  I must be searching for the
wrong thing.  I probably need a specific product.

I've got a qic-150 drive (the large 4x6x.5" carts).  I need a qic-100 drive.

(I suspect it's the same size cart as a TU-58.  I don't plan to use it to
read TU-58's, but who knows, maybe it will read them)


Other Google searches turned up articles in InfoWorld saying the format was
developed by Tallgrass, which explains the ASIC with their name on in inside the
3M/Apple tape mechanism I have pictures of on bitsavers/3M and that Gammamat is QIC-100

At least the on-tape format is documented in the QIC spec.

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