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From: info-vax@ucbvax.ARPA
Newsgroups: fa.info-vax
Subject: Re: Problems writing /FOREIGN tapes
Message-ID: <8660@ucbvax.ARPA>
Date: Mon, 1-Jul-85 01:19:14 EDT
Article-I.D.: ucbvax.8660
Posted: Mon Jul  1 01:19:14 1985
Date-Received: Tue, 2-Jul-85 04:43:02 EDT
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Organization: University of California at Berkeley
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From: goldstein%star.DEC@decwrl.ARPA  (Andy Goldstein)

If you mount a tape /FOREIGN with all the defaults, RMS treats it as
an unblocked tape. This means that when you COPY a file to the tape,
each record in the file ends up as a separate block on the tape.
Dating back from the old NRZI days, the ANSI tape standard says there
shall be no tape records shorter than 18 bytes, shorter records being
presumed to be noise bursts. The VMS (and most other DEC) tape driver
enforces a minimum of 14 bytes, because that's what DOS file labels
were (more ancient history). So anyway, you get the error if the file
contains any lines shorter than 14 characters. COPY could pad the
lines, but then it would have to be told what to pad them with, how
would you unpad them on the other end, and there's much other
ugliness involved. If you mount the tape with /RECORD=n, then RMS
treats the tape as blocked fixed length records of length n. This may
or may not be useful, depending on what you're trying to accomplish.