Date : Sun, 25 Jul 2010 05:51:32 +0100
From : mike@... (Mike Tomlinson)
Subject: Box assorted floppies
In article <4C4710CF.8010502@...>, Rick Murray <rick@...>
writes
>PS: Actually a fair few 'reliability' problems instantly evaporated if
> your admin:
> 1. Uses a REAL clock, not the FileStore's built in one.
> 2. Uses REAL termination.
indeed. But that applies to all Econets, of course.
> 3. Removes all the clock links to completely disable the FS clock.
A good idea, but this means disassembling the FileSnore. They were a
nightmare to take apart and never seemed to go back together quite right
afterwards.
And don't get me started on that stupid front flap with the optical
switch whose tab broke off if you so much as breathed on it, and the
catches that also broke off. I saw many FileSnores with a scrap of
paper wedged into the optical switch and/or the flap taped shut.
The power supply was also a weak point, suffering bad caps after
extended use, surprising as it was fairly well-cooled by the fan
underneath. The same fault applies to the Master Compact, which shares
the FileSnore hardware (not the motherboard, obviously) for its base
unit.
> And yes, they were *painfully* slow.
The very best Econet server was the SJ MDFS. Expensive but beautifully
designed and made and worth the extra moolah. Ran on a Z80 processor
which was a daring step, as up to then Acorn had done everything with
6502 variants.
SJ also produced some superb application notes on how to optimise the
speed of an Econet, taking in various factors. Their async mark/space
clock boxes could be tweaked to improve data rates, unlike Acorn's.
Indeed, Acorn stopped making their own clock boxes and started reselling
SJ's. I got dramatically improved network speeds with a small network
of Masters using short drop cables, for instance, 500k vs. the default
250k, but a Beeb plugged into that would report Net error or Line
jammed.
I had also intended to experiment with an installation not using the
drop leads, but taking the two network cables directly to the DIN plug
on the back of the machine. Removing the stubs from the network line
should have made it possible to increase the speed further. This would
have had to be hardwired, of course, to prevent someone unplugging the
machine from breaking the network, and would have meant two wires to
each station. I was going to use Cat5 cable for this as it was more
manageable than the lousy stuff Acorn recommended (CW1308?)
I used Cat5 for the test network (about 30m) I installed in the workshop
at an Acorn dealer. this was much easier to install and punch down into
the socket boxes and worked fine. I didn't bother trying to keep the
cable run continuous (not trying to avoid cutting it). Green/orange for
D+/D-, C+/C-, both browns for earth and blue unused.
The SJ app notes also discussed the network line speeds that could be
realistically achieved with certain mixes of machine (Beebs being the
lowest common denominator and requiring a slower clock than Masters, for
example.)
--
(\__/)
(='.'=)
(")_(")