On Nov 19 2005, 2:14, Tony Duell wrote:
Are there any Econet enthusiasts here?
Yes :-)
Excellent. And as you saw, Lee Davison pointed me at your last reply to
my question a couple of years back...
> The mainboard contains :
[...]
64K EPROM (2
off 27256). I've not tried to look at their contents yet
There are several versions of the firmware, each with its own little
idiosyncracies ;-) One EPROM is the MOS and the other is the
fileserver code, as you might expect.
Yes, they've got labels on them saying 'MOS' and 'Filestore' or
something
like that. Next time I have it apart I'll see if I can find version
numbers on them.
[...]
An Econet
module (looks like the one used in a Master or Arc, the
type
with the hardware collision detection). Oddly
theres a 26LS30 on the
mainboard, does this thing source the Exonet clock too?
Yes, it does, and it's a decent asymmetric clock. It's supposed to
What is the benefit of an asymmetic clock? Or more precisely, why does
it help?
switch itself off (or actually, I suspect, not switch
on at boot time)
if it detects another clock already on the wire.
I would guess, without any evidence, that it detects the lack of clock
using the same method that a Beeb uses to display the 'no clock' message
and then enables the internal clock if necessary.
and a 34 pin
header. I am told this is to add a hard disk, and it looks similar to
a
Beeb's 1MHz bus. I assume it takes the normal
SASI host adapter and
ST506
bridgboard (I have spares of those somewhere...)
Yes.
I am now confused. Your last message on this (the one Lee pointed me at)
says it uses a SCSI and not SASI disk. I don't think the 34 pin header
carries the SCSI signals (does it? -- I've not removed the PCB yet to
look what it's connected to). Do I use the Acorn host adapter card and
put a SCSI disk on the other side of it? Or is it a special host adapter
that I haven't a hope of finding, or what?
On the front
are 2 LEDs (power and mode) and what looks like a
reflectiove optoswitch (why?)
The optoswitch detects whether the front panel is in the open or closed
state. When closed, the box starts up as a server. When open, it runs
in maintenance mode. The plastic "hinges" were rather fragile and
frequently broke, leading sometimes to the loss of the cover.
Ah, right... Mine is missing the flap, althohgh I can see the holes for
the 'hinges'. I will have to rig something up to operate the optoswtich...
More pressing is the lack of drives and cables. I assume the floppy
drives are plain, 300 rpm, 80 cylinder, ones. Anyhting I should know
about them?
Can anyone tell me anything more about it, how to
use it, what the
intenral links do, etc?
I should have the manual somewhere. You shouldn't need to change any
If you find it, I'd be interested in seeing a copy...
links.
No, probably not, but you know I am curious about such things anyway...
-tony