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Internal boards.....

Posted: Thu Apr 10, 2014 9:33 am
by prime
Hi all,

What are people using to make boards that plug into the chip sockets in the QL ? e.g. Dave's Minerva boards.

I've just finished drilling and soldering up a self made Minerva board using these :

http://www.rapidonline.com/Cables-Conne ... er-22-1704

And these :

http://uk.mouser.com/Search/ProductDeta ... 01-9902001

The latter are individual socket pins that fit into a 1mm hole and allow you to mount the eprom at board level without using the extra height of a socket, which hopefully means the board will just about fit inside the case.

They have two problems though, they are expensive & fiddly to fit, so it would be good to find an alternative. As I have been working on a board that combines a QIMI (with PS/2 interface) and Minerva addon into one board, and so needs 68 of those pins :( (for the ZX8302 & EPROM)

Cheers.

Phill.

Re: Internal boards.....

Posted: Thu Apr 10, 2014 11:30 am
by Peter
You might consider a normal precision DIL socket, e.g.

http://www.reichelt.de/IC-Sockel/GS-28P ... tnr=GS+28P

which you plug deeply into oversized drill holes. With most PCB manufacturing specs these days, the copper rest ring should still be sufficient.

For the QL-SD, I didn't do that, because I wanted a strict ground plane, an the one remaining layer didn't leave me enough routing space in case of larger holes. However, the QL-SD ground plane was more for aesthetic reasons, than being of real use. The layout of the QL mainboard is so much worse anyway.

Re: Internal boards.....

Posted: Thu Apr 10, 2014 3:25 pm
by Dave
I use the turned DIL sockets too. They are super-easy to fit. You can also buy the turned pins loose - not in the plastic carrier. If you position them in a turned socket and use it as a jig, you can surface mount them too.

If you're having a PCB house make them, 1.4mm diameter holes work. If you're doing it yourself, make the whole really tiny, so it acts as a pilot for your drill bit ;)

Re: Internal boards.....

Posted: Thu Apr 10, 2014 3:42 pm
by prime
Dave wrote:I use the turned DIL sockets too. They are super-easy to fit. You can also buy the turned pins loose - not in the plastic carrier.
You can? do you have a link for that as it may be much cheaper :)
If you position them in a turned socket and use it as a jig, you can surface mount them too.

If you're having a PCB house make them, 1.4mm diameter holes work. If you're doing it yourself, make the whole really tiny, so it acts as a pilot for your drill bit ;)
I have surface mounted them before in a stripboard when I made my fist Minerva board,but having to strip them out of the socket was a pain :(

Cheers.

Phill.