This little utility is designed as an accessory for people who own tape-backup drives which use the popular Teac MT-2ST cassette mechanism (150 megabytes, plus or minus a bit).
When you run this desk accessory, it scans your SCSI bus for a Teac drive. Once it finds one, it opens up a small window which displays the tape drive's current status information... tape loaded, tape running, tape write-protected, current track number, time into track, and absolute block number. It also displays the I/O error counts... total blocks retried due to soft read or write errors, total blocks salvaged by use of error-correcting codes, and total retries on a per-track basis.
The status information is updated once every five seconds, or whenever the DA is given a time-slice (whichever happens later). Rewinding or removing the tape resets all of the error counters to zero.
I use this utility to keep an eye on my tapes... especially when I'm running a full-save. It seems to co-exist quite happily with ExpressTape, and it can also be used with Retrospect (although I'm told that the window updates only once per minute or so, because Retrospect hogs the CPU).
The rule of thumb I've heard (I _think_ I read this in some Teac documentation??) is that more than 100 errors per track is a sign that your tape heads are getting dirty and should be cleaned. If this doesn't resolve the problem, your tape may be wearing out and may need to be replaced. Also, if you see _any_ "Error corrected blocks", it means that the data in a block could not be read correctly after 16 tries, and that that only the use of an error-correction code recovered the unreadable data... this may mean that your tape has developed a bad spot.
The utility also provides several commands from the menu bar: Rewind tape, Retension tape, and Erase tape. It's a good idea to retension the tape (wind to the end, and then rewind) if you're going to write data to it and you haven't used it in several weeks, or if the tape has undergone any significant temperature-changes or has been mailed. The "Erase tape" function performs a real erasure (unlike the "Erase tape" command in ExpressTape, which simply overwrites the header).
Install this desk accessory in any of the usual ways (opening it with Suitcase or Master Juggler, or copying it into your System file), or any of the less-usual ways (dragging its contents into your Apple Menu Items folder under System 7, or installing it directly into a copy of your backup application using the Font/DA Mover's option-click trick).
This utility is Copyright 1991, Dave Platt. It may be used for free, distributed for free, and distributed as part of software libraries maintained by not-for-profit organizations. It may not be sold by for-profit organizations, or bundled with hardware sold by for-profit organizations, without the author's express written permission.
