Page 1 of 2

Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 10:45 am
by genetika
Hi.
I would like to use the MiniATX Case for the QL.
I have superhermes chip with external keyboard interface, SuperGold Card, Qubide, Minerva, a backplane and a Scart cable.

Is it difficult ? :-)

thanks !

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 11:19 am
by Peter
I did something similar a long time ago. If you have no Aurora, check mainboard space carefully. You will need to drill a lot of holes, also you will need to use cables to bring SERs and Joystick to the back. You will also need to think about removable media. (Your case does not seem to have an external 3.5" bay for floppy!) Also there will be some wiring/soldering for power supply, LEDs, etc.

Since you leave the original QL case anway, and use a PS/2 keyboard: Wouldn't the Q68 make your life much easier? ;)

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 12:59 pm
by genetika
Hi peter.
Yes, I think the Q68 is better... :-)
Too much work for the original QL ..

M.

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 3:30 pm
by Derek_Stewart
Hi,

I do not think it is difficult. But there maybe modifications to the case to suit the QL boards.

I am assuming you are going use an Mplane.

I fitted an Aurora with SGC, Qubide, Mplane into a Black Shuttle case. The case needed a slight modification to cope with the size of the Mplane width.

Also the ATX Power Supply will need the PS_ON line shorted to GND. Or I fitted a swich to swit h on/off.

It is a little bit of work . But works okay.

I also did this for a Q60 10 years ago...

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 4:10 pm
by Dave
A 74HCT74 seems like a much more civilized way to go about power control ;)

The main problem of a QL in a Mini-ATX case is the length of the QL mainboard, at 37.7 cm.

The Aurora works better, being 16.5cm.

I can add an ATX powered custom backplane to my next order if I have a clear idea what people need. I have been designing the QL2 around a HTPC case, which is very stylish, compact, but gives the size required plus flexible power options.

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 4:25 pm
by Derek_Stewart
Sounds great. If we ever see the back plane...

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 4:44 pm
by Dave
It only exists as a schematic and layout, and one PCB that I ordered and is in a machine ;)

I can re-organize the connectors any way that is needed and redo the PCB very quickly (a couple of hours) - just need to know the outer limits of the PCB, the orientation and spacing of the expansions, etc.

My take on mPlane would be simple: it would be 2cm wider so the expansions didn't overlap the QL, and to the other side so the expansion would be in front not behind the QL, and there would be four through connectors, not three.
ATXplane...
ATXplane...
Since I did this design, I also added buffers...

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 5:08 pm
by Peter
Dave wrote:A 74HCT74 seems like a much more civilized way to go about power control ;)
This is how I did it:
ATXPowerSwitch.pdf
(18.75 KiB) Downloaded 142 times

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 5:15 pm
by Dave
Will yours work with a momentary switch?

Does it bias the flip flop so it defaults to power on or power off after a power failure? ;)

Re: Sinclair QL on MiniATX case.

Posted: Mon Mar 12, 2018 5:18 pm
by Dave
(I did this with a resistor divider and small cap on the CLR pin, plus a jumper to short the capacitor, so I could have instant or delayed rise on the CLR pin which sets the flipflop not just into a known state, but a selectable state...)