DEC TK50-GA tape drive/ Windows 9x

From: Jerome Fine <jhfine_at_idirect.com>
Date: Mon Oct 8 08:31:03 2001

>Chuck McManis wrote:

> At 10:22 AM 10/7/01 -0600, you wrote:
> >I own a pair of DEC TK50-GA external SCSI tape drives which I'd like to
> >use as storage on my PC (Windows 98).
> >Can anyone tell me:
> > 1. if this is possible
> > 2. if possible, what hardware/software is required
> > 3. source(s) of required hardware/software
> >Kevin Wright
> >Email: <mailto:callwright_at_earthlink.net>callwright_at_earthlink.net
> 1) Yes.
> 2) You need a SCSI-1 controller (like the Adaptec AHA-15xx series). No
> particular software is needed (The Adaptec EZSCSI software will make it
> show up as a tape drive to windows backup)
> 3) Ebay, the local surplus PC shop, ham fests, boot sales, asking around.
> However, why would you want to do this? The tape is only capable of
> recording 95MB/taps. It is notoriously prone to "eating" tapes, and the
> minimum disk size for Win98 is 2GB (which would take about 24 tapes to back
> up)
> Now, it occurred to me that you may have thought "ohhh, DLT drive, 10 to 20
> GB per tape." and if that was the case I hate to disappoint you. You'd
> would need to find a TZ89 rather than a TZ85.

Jerome Fine replies:

Of course, IF you want to use the TK50-GA as a backup/exchange device for
use with a PDP-11 emulator on the PC system, that is another matter. However,
I suggest that you consider reason:
4) The TK50 drive (used in both a TK50-GA and it is the TK50-AA) is probably
the slowest tape drive around (unless you include the TU-58).

As an exchange media for off-site use less than a few times a year and for very
small volumes of data (less than 100 MBytes - even a single Zip cartridge can
hold 100 MBytes and is MUCH faster) AND for older software systems like
the PDP-11 and even a uVAX II, the TK50-GA might be considered reasonable.

However, when used for backup purposes more than a few times a year, I doubt
that many people would consider it a reasonable solution. While the tape WRITE
speed might be just barely sufficient if the software can keep the drive streaming,
if you ever attempt to do a VERIFY (generally useful to be sure that the tape can
be read back - otherwise, depending on a backup is questionable), you may find
that is takes too long. I did just once and quit before it was even half finished.
I also gave up on using the TK50 as a backup drive even with a PDP-11 under
RT-11.

Sincerely yours,

Jerome Fine
Received on Mon Oct 08 2001 - 08:31:03 BST