The Museum of HP Calculators

HP Forum Archive 13

[ Return to Index | Top of Index ]

Help repairing a Digital Cassette Tape
Message #1 Posted by Philip on 18 Nov 2003, 10:27 p.m.

I have Digital Cassette Tape to be used in the 82161A Tape Drive that appears to be broken. I can't tell if the tape came apart at the end or somewhere in the middle. Does anyone have suggestions on how to repair or splice these things?

Thanks

      
Re: Help repairing a Digital Cassette Tape
Message #2 Posted by Victor Koechli on 19 Nov 2003, 2:09 a.m.,
in response to message #1 by Philip

Hmmm, I've never had to repair one (so far). I can't think of any other means than splicing the tape, just like an ordinary audio cassette (you know, that rectangular pre-CD-thing that could not even handle MP3 ;-))). I can think of two problems:

- If the tape is broken at the beginning, there is an index hole in the tape that the drive can 'see' with an optical sensor (there's a little mirror in the cassette for this purpose). Be sure not to obscure this hole, or to make a new one, if you have to cut it out.

- I don't know how much of the tape's total length you can cut out before running into problems. My guess is that the INITIALIZE command assumes a fixed tape length to hold a fixed number of records. Therefore, cut out as little tape as you can, but as much as necessary in order to avoid defective records.

As your tape is broken, you probably have no alternative than trying to splice it anyway. Good luck, and keep us informed.

Cheers, Victor

PS If you want, I can have a look into the drive's manual once I get home. This will only be in 10 hours, however (I just got to work...)

      
Re: Help repairing a Digital Cassette Tape
Message #3 Posted by Diego Diaz on 19 Nov 2003, 6:00 a.m.,
in response to message #1 by Philip

Hi Philip,

Here you can read what I did to fix some of my tapes.

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv009.cgi?read=24257

Wish you succeed!

Regards.

            
Re: Help repairing a Digital Cassette Tape
Message #4 Posted by Victor Koechli on 19 Nov 2003, 7:26 a.m.,
in response to message #3 by Diego Diaz

Thank you, Diego, for that excellent article! Actually, I think it should be moved to the 'articles' section, possibly along with additional information from Tony Duell concerning the pressure pad.

Do you have an idea how much of the tape's total length can be sacrificed before it gets too short? Or is tere an alternative NEWM command that allows for shorter-than-normal tapes? If so, it would not always be necessary to replace the entire tape, but you could easily splice it after cutting out the damaged section.

Kind regards, Victor

                  
Re: Help repairing a Digital Cassette Tape
Message #5 Posted by Diego Diaz on 19 Nov 2003, 8:39 a.m.,
in response to message #4 by Victor Koechli

Hi Victor,

Unfortunately I can't tell how much "spare" tape is in the mini-cassette, I'd bet it won't be too much though.

I simply try to make my "rebuilt" as close as possible to original specs.

There is BTW an inacurracy in my article, I told about "constant angular speed" of the reel, it should be far more precise to say that the "sum of the angular speeds of both reels" is what the 82161A tape speed control cares about. Anyhow, that makes no difference from a user (fixer) point of view.

Cheers.

            
Re: Help repairing a Digital Cassette Tape
Message #6 Posted by Mark Hardman on 19 Nov 2003, 10:31 p.m.,
in response to message #3 by Diego Diaz

Thank you Diego!!! I'm off to try this on my own set of decaying tapes. Have you ever thought of expanding on this and posting it in the Articles section?


[ Return to Index | Top of Index ]

Go back to the main exhibit hall