30 Jan
2011
30 Jan
'11
10:46 a.m.
Tony Duell wrote:
Well, I've not got a digital camera yet :-). I wonder if I could convince
an HPCC member to photograph it for me at a meeting. Of course this means
finding the darn board...
Incidnetlaly, I've just rememberd I ahve a
somwaht odd RML380Z board
soemwhere. It's got a bit off address deocding logic on it,
interconnected by PCB tracks. And 3 (I think) Z80-PIOs and a Z80-CTC in
wire-wrap sockets. The Z80 bus linesare are connected to the 380Z bus
connector, etc. the port lines and the counter/timer signals go nowhere.
There's also a little prototyping area on the board and space to fit some
header plugs. The idea is that you make your own custom interfce by
adding the logic you need and wire-wrapping it to the PIO and CTC pins.
Ans wire-wrap it to a header plug to connect a cable to the peripheral.
Hmm, is there any way you can get a scan/photo to me? I'd love to see that. I've seen another system with an analogue board
inside, and enough guts for
six serial ports.
IIRC, at least one of the serial port boards was a disk cotnroller/serial
board with the former circuitry not fitted. There was also an
'intellegent' disk cotnroller/serial board which had a Z80 on it, I think
that was used, with different ROMs, as the controller in the 480Z disk
unit (which had a synchronous RS232 interface to the host).
What I have never seen are any of the currnet loop serial options which
were supposed to exist.
I would love
to find some of the other board too. There was rumoured to
be an GPIB board. And an Econet interface. Oh, and a scheamtic of the
cassette control box would be intreresting.
GPIB I can imagine - I've never heard of an Econet interface, though; that would be an interesting find (as would any software to
make use of it). I
wonder if that was a commercial offering (I'm surprised that RML would be
allowed without Acorn getting upset - maybe via a third party, though?) or if
it was someone's homebrew...
I haev never seen it, but 'The Econet Micro Guide' by C. Dawkins says :
'Econet hardware has been impleemnted for the Apple ][, the Nascoms 1 and
2, the Research Machins 380Z and 480Z, S100 bus machines and all Acorn
computers, but only the last 4 are commecially available.'
A little later it says
'The 380Z/480Z/S100 interfaces have the same driver, receiver, collision
and idle detect circuiry as the BBC -- which at least ensures electrical
compatibility -- but the ADLC functions are performed by the SIO chip.
Only aobut half the hardware on the 380Z board is required for the
Econet ; the rest is a 64K RAM expansion and a ROM socket, with the
necessary decoding for the RAM to be paged as required. One important use
for this paged RAM is when the 380Z is acting as a fileserver -- the RAM
on the Econet board then provides cache memory which considerably speeds
up opeeration.'
The 'ADLC' is the 6854 of course, the 'SIO' is a Z80-SIO chip.
Fuses generally blow for a reason. I asusme this
is a mains fuse (in
series with the live side of the mains), in which case the problem could
be a short on the primary side (e.g. a filter capacitor, if they're after
the fuse), or a short on the seondary side (redtifer diode, smoothing
capacitor, etc0.
That's true - I was thinking that Adrian had a fault somewhere in one of the
boards, but I suppose it could just as easily be in the PSU itself (and easy to determine as I'm pretty sure the RML supplies
are simple enough to run with
no load connected)
Indeed they are.
Of course findign a 100W bulb these days is a
problem :-(
Yes, getting that way here, too! Maybe it's possible to get a heat lamp bulb
of the right wattage, though. The one I have here (to stop the dogs freezing