19 Sep
2004
19 Sep
'04
8:28 a.m.
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 the 2 or 4Hz clock output from the decoder into the
printer port; the
user port is tied up handling the digital representation of the analogue
satellite signal.
Incidentally, the docs actually contain full schematics (it's not a
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 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 am told this machine was used to receive the weather satellite images
for the BBC weather forcasts at one point....
-tony