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- From: rnichols@cbnewsg.cb.att.com (robert.k.nichols)
- Subject: Re: reading to end of tape
- Message-ID: <1992Nov8.221824.8823@cbfsb.cb.att.com>
- Summary: The full-width erase head hits all tracks at once.
- Sender: news@cbfsb.cb.att.com
- Organization: AT&T
- References: <1992Nov8.010807.8693@cs.rochester.edu>
- Date: Sun, 8 Nov 1992 22:18:24 GMT
- Lines: 20
-
- In article <1992Nov8.010807.8693@cs.rochester.edu> joel@cs.rochester.edu writes:
- >Does anyone have any suggestions for reading past the "end of recorded
- >medium (eom)" or "logical end of tape" on a magnetic tape? My tape is
- >a 3M Magnus 1.0 (QIC-1000), my drive is a Tandberg 4120, my adapter is
- >an Adaptec 1542B, and my operating system is OS/2 2.0. Since I wrote
- >the tar file I want, I rewound the tape (without erasing) and started
- >writing from the beginning, but I think the file should still be
- >there.
- ...
-
- One problem with trying to recover data in this circumstance is the way
- that QIC drives perform erasure. There is one full-width erase head,
- which is activated whenever the drive is writing on Track 0. It erases
- all of the tracks. Thus, if your original file occupied multiple
- tracks, there will be erased sections at the beginning of each
- even-numbered track and the end of each odd-numbered track.
-
- Bob Nichols
- AT&T Bell Laboratories
- rnichols@ihlpm.ih.att.com
-