Date : Sun, 03 Jan 1999 11:10:59 +0000
From : Mike Tomlinson <mike@...>
Subject: Re: Using PC keyboards & PC cases
In article <199901030957.KAA28888@...>, Mark Usher
<marku@...> writes
>IIRC Mike T. did mention that he had quite happily used up to 2 metre ribbon
>cable extensions to the BBC keyboard.
Correct. It's only TTL levels, after all - the same as parallel printer
cables, which often will work up to 10 metres. Use a 34 way ribbon
cable - only half of it gets used as the keyboard ribbon is 17 way. If
you're worried about RF emissions, ground the spare 17 ways.
Viglen's conversion kit for the BBC to turn it into a desktop machine
containing the floppy drives used a curly cable for the keyboard - which
would have been about 3 metres fully stretched, I think.
>Strange really that you should post this as I was thinking something similar
>this last week. I have just transplanted my BBC into a PC Tower casing which
>is an unbelievable improvement on space around my desk.
Oh Mark, IhateyouIhateyouIhateyou. I've got a spare PC tower case doing
nothing here and only last week boxed up my Beeb and all the bits and
put it in the loft. Now you've planted the idea in my head, I'm not
going to be able to resist doing a conversion! Tsk. I've just given
away my monitor as well.
The more I think about it, the more obvious it seems. The floppy drives
will fit perfectly, the PC speaker can be used, the PC PSU is amply
specced and has cooling, there's plenty of room for z80 and shadow RAM
boards, a hard disc will be easy to fit and the adapter boards can be
mounted in spare 5.25" bays, the LED speed readout on the front of the
case can be altered to read 2(MHz) or perhaps even 'BBC'.
The hole for the keyboard socket on the case would be perfect for a
monitor plug.
>- the reset
>switch also neatly attached
wire it in parallel with the Break key...
>(although a reset never works correctly when I
>turn on the co-pro and then reset - it always boots to the * prompt instead
>of >).
hold down Ctrl when pressing reset...
>All I have to do is respray the case
black? Beeb beige? blue with pink spots?
> and somehow make a decent keyboard
>extension.
find a curly cable with at least 17 ways and two 34 way IDC connectors
salvaged from a scrap floppy cable. A bit of careful fiddling with a
vice, and presto! Or advertise for a Viglen kit, throw away the desktop
bit and keep the keyboard housing and cable.
Alternatively, you can buy flexible braided tubing (anyone who has seen
the SCSI cable used in IBM PS/2 machines will know what I mean). You
could split a 34 way ribbon cable about every 5 strands (to make it
flexible), leaving the ends intact to allow clamping into IDC
connectors, and then work it into this tubing - should look quite neat.
All the best for a happy New Year to all on the list.
--
Mike Tomlinson
See the sci.electronics.repair FAQ mirror at
http://www.jasper.demon.co.uk/repairfaq/