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Re: New QL backplane.

Posted: Wed May 17, 2017 9:59 pm
by Paul
Looks great! Thanks for the update Dave.

Re: New QL backplane.

Posted: Wed May 17, 2017 10:54 pm
by Dave
There is going to be a version 2. This one works nicely, and doesn't introduce a lot of noise into the lines like the old QPlane did, but it would be nice to add some pull-ups, pull-downs, a couple of capacitors, blinkenlights, a flux capacitor, go-faster stripes from a 1978 Ford Escort, TARDIS console, you know the sort of thing.

Re: New QL backplane.

Posted: Thu May 18, 2017 4:16 pm
by Dave
Design verified. It works well. Doesn't introduce a lot of noise into signals, and having two cards in actually seems to clean up bouncing on a few lines which is a nice and unexpected finding. It really is a tight squeeze under the keyboard, with the metal plate touching the top edge of the backplane. Insulation is absolutely necessary and will be included.

Putting washers on the front and back case screws on the left side of the QL case gives an extra 1mm. That extra air gap results in a slightly cooler QL. It's not possible to carry that all the way across to the right because the upper case position relative to the microdrive units is critical. The right front two screws can't be trifled with!

Now to put together a little manual for it. It has to cover assembly if you self-build, use, and a disclaimer about overloading your QL power supply if you put three SGCs on it!

Re: New QL backplane.

Posted: Fri May 19, 2017 5:01 am
by Paul
Dave wrote:and a disclaimer about overloading your QL power supply if you put three SGCs on it!
So you could attach 12 ED floppy disk drives? :mrgreen:

Re: New QL backplane.

Posted: Fri May 19, 2017 5:09 am
by Dave
No, for that you'll need a Super Duper Mega Ultra Trump Card++

Re: New QL backplane.

Posted: Fri May 19, 2017 12:15 pm
by 1024MAK
Only 12 drives :shock:

That's not what I call mass expansion...

I would want a 4 by 4 bank of drives as a minimum.

Now where did I put that nuclear power station that I want it to control...!!!!

Mark

Re: New QL backplane.

Posted: Fri May 19, 2017 4:29 pm
by Dave
That's not even funny. A Sinclair QL was used in a nuclear power station in the 80s. I know we used one at Sizewell because I saw it with my own eyes.

If it was a Beeb it might still even be in use today.

Re: New QL backplane.

Posted: Fri May 19, 2017 5:47 pm
by Paul
Dave wrote:That's not even funny.
I'm sorry. I meant it to be a joke. I shouldn't try posting funny thing when I don't understand the language enough.
Kind regards Paul

Re: New QL backplane.

Posted: Fri May 19, 2017 6:49 pm
by 1024MAK
Paul wrote:
Dave wrote:That's not even funny.
I'm sorry. I meant it to be a joke. I shouldn't try posting funny thing when I don't understand the language enough.
Kind regards Paul
Paul, I think it was my post that caused the meltdown (sorry)...

Mark

Re: New QL backplane.

Posted: Fri May 19, 2017 7:57 pm
by Dave
Paul wrote:
Dave wrote:That's not even funny.
I'm sorry. I meant it to be a joke. I shouldn't try posting funny thing when I don't understand the language enough.
Kind regards Paul
:D