Early 3M Computer Tape Type Numbers

[Tom Gardner]

Paul

Thanks, I had found this ad a while ago but thought it was ¼-inch.  Upon careful reading all the notes I found, "Errors per roll based on recording 7 tracks on rolls ½" x 2500'. "

It looks like 3M may have called their computer tapes "Instrumentation" tape until the late 60s

Tom


-----Original Message-----
From: Paul Koning [mailto:paulkoning at comcast.net] 
Sent: Thursday, June 25, 2020 5:15 PM
To: Chuck Guzis; cctalk at classiccmp.org
Subject: Re: Early 3M Computer Tape Type Numbers



> On Jun 25, 2020, at 5:14 PM, Chuck Guzis via cctalk <cctalk at classiccmp.org> wrote:
> 
> On 6/25/20 1:55 PM, Tom Gardner via cctalk wrote:
>> I'm trying to figure out what were the earliest Type numbers for 3M 
>>  -inch reel-to-reel computer tape
>> 
>> As best I can find, 3M began marketing a Type 777 computer tape about 1967.  The Type 700 appears to be somewhat later.  But 3M sold computer tape directly to at least government customers (e.g. NSA, Social Security) in the 1950s.  The also notably OEMed tape to IBM who rebranded it under an IBM label until the late 1960s at which point with the help of Sony IBM began manufacturing its own computer tape.
>> 
>> Anyone have any idea of the Type number for 3M computer tapes earlier than Type 777?
>> 
>> There might be a place for some of these older Types at the CHM if anyone knows of any still in existence.
>> 
>> Tom
>> 
>> PS:  There is a lot of information on 3M audio tape Type numbers as 
>> at http://www.aes.org/aeshc/docs/3mtape/aorprod-cust.pdf but computer 
>> tape seems to be an orphan
> I probably do--but I'm going to have to look through my logs.  Old 3M 
> tape is terrible for binder that sticks to everything.  Before 
> processing the stuff, I have to lubricate it.

Except for DECtape, of course.  That's 3M 340 or 341, the spec (from Nov 1966) is here: http://www.bitsavers.org/pdf/dec/dectape/3M_DECtape_Spec_Nov66.pdf

	paul