QL VGA Case

I’m still having a lot of success with the prototype QL-VGA board from Marcel Kilgus. To recap, it’s a board which allows the QL RGB output socket to be connected to a SVGA monitor, something which was difficult or impossible before this unless you had some form of SCART to HDMI converter, and even those didn’t work with all screens. My original article about QL-VGA can be found here.

Prototype working QL-VGA

Finding myself with some unexpected time at home, I decided to case my QL-VGA board. Both to make it look a little nicer on my desk and to protect it from dust and damage.

I’d already ordered two different cases for this job from Electro-Mart UK. The smaller box sounded like a perfect fit, but I know from experience that some online measurements may not tell the whole story as you can’t tell if there are internal ridges, mounting pillars etc to reduce the workable internal dimensions.

Box used ot create a QL-VGA enclosure.
The ABS box I bought

As it turned out, this case was almost a perfect fit for the prototype QL-VGA boards, and with a little bit of careful filing of the lid’s screw pillars, I just about got the smaller of the two cases to take the twin stacked boards with only minor compromises.

It’s a UK manufactured plastic ABS box measuring 113 X 59 X 24mm. It cost £4.98 and delivered in just a few days from ElectromartUK’s eBay store.

The first step was to work out the number, size and type of holes I needed to make for the plugs and sockets. Three are required. The connectors end up almost flush with the surface, so provided the connectors are not too large (e.g. an SVGA connector needs access to the two screw connection holes alongside the connector itself), you can afford to allow a little extra room if the cables have slightly larger connectors than those on the board.

I drilled a hole for the power connector towards the rear of the long edge of the case and took the simpler step of removing the entire front of the case for the SVGA and QL video connectors as I couldn’t see what remained of the front panel being strong enough if I simply made two holes of the right size.

Another issue was that the end with the pillars into which the box lid retaining screws fitted was about 1.5mm too narrow for the leading corners of the QL-SVGA boards. So I had to file the pillars down slightly. In fact, I slightly overdid it and slightly damaged the mounting pillar, but it works.

Fitting the board in after making the holes.
Fitting QL-VGA into the box after making the holes.

I had hoped that drilling a simple round hole would have been enough for the power connector. However, frustratingly, the power socket sticks about about 0.5-1mm too much for this box, so I ended up going for a square cutout instead so that the power socket could stick partially out of the side of the case. Not as neat and tidy, but it worked well enough in practice. I had to bear in mind that the SVGA socket onthe board sticks out further than the little S-VHS type connector for the QL video, so had to make sure I allowed a larger access hole for the QL video connection, as the S-VHS min 8 pin DIN plug is wider than the socket, hence why the holes in the pictures look slightly larger than they might need to be.

By now I was starting to feel optimistic. The QL-VGA prototype (and remember, it’s a prototype, the finished product may differ slightly) was a snug fit inside the case and didn’t need any mounting pillars or screws within the case. If you need to mount it securely in a slightly larger case, I’m sure you could use an insulated double sided tape under the bottom board, for example. The prototype QL-VGA boards do have mounting holes in the corners if need be.

Plug everything together and power up to test it. I can see Marcel quaking with fear at this point with thoughts going through his mighty mind as to how many ways Dilwyn could have destroyed his masterpiece. But worry not, it worked first time. So on goes the lid and make a nice logo for it which I printed onto a sticky label for the lid.

Ready to go!

Now, there are one or two considerations. You can’t see the on-board status LED lights when the lid is on. You may be concerned about overheating when cased up like this. The slightly oversize holes probably help but it doesn’t seem to have gone very hot in the few hours it’s been switched on before I write this. I suppose it’d be easy enough to drill small holes into the case and perhaps raise the box with feet to allow air to flow underneath – I just don’t know what the current consumption of the finished boards will be to know how warm they’ll get.

So, to end with, here’s a picture of the finished QL setup. You might consider encasing the QL-VGA in this manner to be overkill, I happen to think it’s a lot neater looking than the bare boards. Thank you once more, Marcel, for all your work in designing this useful little gadget.

QL setup with cased QL-VGA
The finished QL setup.

2 thoughts on “QL VGA Case

  1. Nice one Dilwyn. That said I would want so much more from that FPGA such as a VGA resolution adjunct to the main screen. That said it would be impossible with out much more invasive access to the QL it’s self!

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