Whitechapel Computer Works MG-1
ard at p850ug1.demon.co.uk
Sun Nov 30 23:53:41 CST 2014
> On 11/30/2014 12:51 AM, tony duell wrote:
> > It needs a good set of NiCd cells on the power control board to start it up.
> > If not, you have to do a 'jumpstart' involving connecting a 9V battery to a connector
> > on that board. Some owners added an external socket wired there to make it
> > easier to so this.
> I think I've seen four of the machines in total; every single one of them
> had suffered significant corrosion to the main PCB beneath because of the
The main problem in my experience is corrosion of the (tin plated) Molex
KK connector between the power control/battery PCB and the motherboard
This carries the system power (!) and corrosion leads to all sorts of problems
due to the fact that the 5V line is anything but.
> > There is a rare adapter which adds 3 ISA slots. 8 bit ones IIRC.
> I know the CG-200 at NMoC has such an adapter. I've actually got a photo of
> it here - it has 3x 8-bit ISA slots toward the rear of the system, as you
> say, but then there are PCB traces at the other end of the adapter board
> for three 64-pin sockets, although only one is physically fitted on NMoC's
> machine. Purpose unknown, and it'd be interesting to know if anything ever
> made use of it.
I seem to remember those connectors are essentially the 32016 bus. I've never
seen them used for anything. Maybe in a few months time when I have unpacked
all my books I can find the technical manual and see...
> That particular system has an ISA serial board and some flavour of ISA
> video board (whatever the latter is, it has 8x 41264 dual-port RAM chips,
> and there's a 20-way ribbon cable attached which runs off somewhere beneath
> the ISA adapter board). Unfortunately the machine - like the MG-1's - had
> also suffered significant corrosion.
I wonder if that's the colour video output card. Does this CG200 have the normal
MG1 motherboard in it? I seem to remember a connector on the motherboard
that carried at least the video timing signals.
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