I understand that Verbatim are selling comparable drives at £370 pounds plus VAT,
and at that price they are really not worth considering for the amateur (or even the
professional, unless someone else is paying) with Winchesters-on-a-card available
for less for IBM compatible machines.
At the price offered, they are excellent value. Many thanks, Scorpio, for giving me
many hours of innocent fun, and my elderly NASCOM 2 a substantial new lease of
It took a week or two of routine use before I came across another problem, which
was more obscure, and I still do not fully understand. During the course of an editing
session, records of 128 bytes were being written to a file, which might be closed then
re-opened for use by a “chained” program. If the drive motors had timed out in the
interim, some records were lost in the middle of this file, while later records were
written at the correct relative position in the file.
This problem was solved by ensuring that the routine which checked for motor-on
status would load the heads, and wait for a short settling time before proceeding, if
the motors had stopped. This appeared to duplicate a head-load and delay section
in the sector write routine. I had expected that ifthe heads were not properly loaded,
the relevant physical sector would not be found, a sector-write would not be
attempted, and an error flag returned to the BIOS. In this instance, the write failure
was not flagged.
I am still not happy with this explanation, but so far all seems to be well!
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Gemini MultiBoard System in 19" frame. P.S.U., 8-slot backplane, GM813
CPU/RAM, GM812 IVC, GM829 FDC, GM827 keyboard, GM808 EPROM
programmer. CP/M 2.2, BBCBASIC (Z80), MBASIC, Tiny BASIC, several disks
Public Domain software, many manuals, 80-BUS News, etc. Used < 2000 hours. It
cost me £1200 – I’m open to sensible offers. Telephone: Chris Hellen, Wivenhoe