19 Sep
2004
19 Sep
'04
11:17 a.m.
On Sun, 2004-09-19 at 21:28 +0100, Tony Duell wrote:
Right. The Maplin one (Published in the Maplin Magazine) used only the
user port IIRC.
I've got another one (decoder only) which looks very Maplin-ey. That one
just has a pair of SPDT switches on the front along with a meter marked
0-10, whilst at the back there's just power, and a pair of DIN sockets -
both 5 pin, although one's arranged in a 'circular' pattern and the
other's more like an 'H'. No labels on any of that.
I have no idea what this one's for - it's all CMOS logic inside, apart
So has anyone ever heard of the Beeb printer port
being used for
something other than a parallel printer?
The docs for the Timestep weather satellite decoder which I have in
front of me say that the unit uses the printer port. It appears to feed from an 084 op-amp chip. Not too complex, so I'll
trace the circuit out
one day. It's marked as being for UoSAT on the PCB, but
unless data's
clocked out serially it doesn't logically seem to be for decoding
imagery.
The Maplin Mags contains schematics for the receiver
and decoder. Alas
the receiver PCB was supplied ready-build so there's no alighment info
:-(. Oh well...
I'll have to see what's in the docs I have. There's a bit of info about
calibration in the Timestep info, plus I've got a copy of the original
doc released by Surrey uni about UoSAT which is a combination of sales-
like material and useful technical information. Luckily for me it seems
to go into some detail about how to make an aerial suited to the UoSAT
satellites (as I don't have one), plus various others over on the BBC
list have been most helpful [waves at Charles and Pete]
I do have a 'real' weather satellite receiver
system. It came from
ic.ac.uk, and the bit I really wanted (and got) were the 3 I2S image
processor/display units (really interesting graphics displays for
PDP11/VAXen), complete with schematics, etc. I didn't get the computer (a
VAX), but I did get the indoor bits of the receiver -- everything from
the 137MHz 1st IF onwards, and the first local oscillator at a couple of
GHz. I didn;t get the dish or first mizer. This part is clearly home-made
(well made, but it's a 1-off -- the RF bits are built by 'dead bugging'
on a copper-clad-board ground plane in metal screening boxes, the digital
bit is on stripboard..
I'd forgotten you had that. Do you have sufficient software to make it
do something as a complete system if a suitable VAX were found, or has
that part of it been consigned to oblivion? It'd be pretty amazing to
have that grabbing images and displaying them somewhere :-) (presumably
the satellites it was designed to work with are still operational)
cheers
Jules
--
"We've had a lot of loonies around this place, but you're the first one
who thought the sunrise was made out of stale beer. Now are you going to
pick up your flute and leave, or shall I part your hair with this
crowbar?"