The Sinclair QL Forum

Andrew wrote:

Peter wrote:I mount them with this method: Turn the QL case top 90 degree to the right. Then insert both cables straight, like into the SInclair motherboard. Then turn back the case top carefully and close it, giving the cables a 90 degree curve.

Wouldn't this create a lot of stress in the membrane's ribbon cables that would eventually generate cracks?

Even in the stock QL, the keyboard trails are bent in an s-shape from the sockets - folded through 90 towards the front of the case, and then through 180 towards the back of the case - at the point they go beneath the metal cover - there is a very tight fold.

Perhaps the newer membranes can accept a 90 degree crease.

Andrew wrote:Wouldn't this create a lot of stress in the membrane's ribbon cables that would eventually generate cracks?

I did not try with the 37 year old membrane, and would not recommend using it with this board directly.
With a replacement membrane it appeared okay to me. I unfixed the corner of the double-sided adhesive tape to create less stress.

It was a difficult design decision not to make the board wide enough for the original connector locations. But otherwise standalone usefulness would have suffered.

I had also considered two separate baseboards for QL case and standalone. But that would make estimating user demand more difficult, splitting the small numbers in even smaller ones.

Andrew wrote:Wouldn't this create a lot of stress in the membrane's ribbon cables that would eventually generate cracks?

One could create an add-on with normal ribbon cable that would move the connectors to a more natural spot. Shouldn't be too difficult.

bwinkel67 wrote:One could create an add-on with normal ribbon cable that would move the connectors to a more natural spot. Shouldn't be too difficult.

Yes, that is an option. But a better option would be to already have the connectors on a ribbon cable soldered on the board or connected to the board using a pin header.
(I am useless at soldering)

Internally, the baseboard converts from QL matrix to PS/2. But it also has a 4 pin header where the PS/2 signal from an external source can be attached.
So it is possible to use the little matrix-PS/2 converter board at the original place, and a simple 3 wire + shield cable to the baseboard.
But honestly, just getting a replacement membrane makes more sense to me than extending the wiring.

Peter wrote:But honestly, just getting a replacement membrane makes more sense to me than extending the wiring.

I agree with this. A new membrane is a pretty cheap upgrade, and the replacement ones feel a lot more durable than the Sinclair ones (I seem to recall they were fragile even back in the '80s).

lostcarpark wrote:

Peter wrote:But honestly, just getting a replacement membrane makes more sense to me than extending the wiring.

I agree with this. A new membrane is a pretty cheap upgrade, and the replacement ones feel a lot more durable than the Sinclair ones (I seem to recall they were fragile even back in the '80s).

Errrr, you don't sell them by any chance?

I just bought a replacement keyboard for Acer ZG5 laptop £7 delivered from Amazon. You can get wireless keyboard with mouse for £9 off Ebay. The only QL membranes I see are at £17.50

OK, I know they are invaluable and we are grateful that someone has gone to the trouble and expense to reproduce them, but I don't think I would use the term 'cheap' relative to what £17.50 would get nowadays

Additional: A QL keyboard like done like this for ZX range would be better value https://www.ginger-electronic.com/en/10-retro-computer

ones' complement wrote: Errrr, you don't sell them by any chance?

No. I just spent €23 on one from Sintech Deutschland. I guess cheap is a relative term. I can understand that a replacement membrane for a 38 year old computer that wasn't a best seller in its day, is something of a niche product, and won't benefit from economies of scale.

ones' complement wrote:Additional: A QL keyboard like done like this for ZX range would be better value https://www.ginger-electronic.com/en/10-retro-computer

That would be very nice to have for the QL!

Peter wrote:But honestly, just getting a replacement membrane makes more sense to me than extending the wiring.

I have new membranes on all my working QLs. Sill, I'm not sure how long a new membrane with 90 degrees twist will it last.

ones' complement wrote:Additional: A QL keyboard like done like this for ZX range would be better value https://www.ginger-electronic.com/en/10-retro-computer

There will be one soon, afaik: https://www.theqlforum.com/viewtopic.php?f=2&t=4035
The drawback is that you have to cut the case top.