PQNG #2

Continuing a bit with the Pqng project, I constructed a second unit for Melwyn in return for making the software. I had been thinking about a desktop model and as Melwyn preferred it over a wall-mount one I decided to give it a spin. Besides the power supply (stripped from a DVD player), the hardware is the same as before.

Modified assembly frame with the CPU and backlight transformer installed.

The “desktop model” is simply equipped with a stand that keeps the unit in a upright position. I decided to test integrating the power connector to the stand.. with proper insulation added of course.

Support stand

PSU connector mounted to support stand

If the power connector was mounted to the unit itself, it could be easily converted to a wall-mount model. This would require reorganizing the sub-component layout as there really isn’t room for the connector in the current one.

Rear view of assembled unit.

PSU connector

Reset switch soldered directly to CPU module.

I decided to test “bundling up” the floppy cable by cutting it to smaller stripes and wrapping them together with some twist ties. Apparently, this a mod some computer geeks use to make the cables less wide so that when installed inside a computer, they cables don’t obstruct airflow as much :)

Side view of completed unit.

First boot..

Adding some kind of a boot-time display turn-on control would definitely make Pqng more ‘classy’ in a way. So to say, to prevent the bootup screens (BIOS etc.) from appearing on-screen. Probably the easiest option would be to add a simple RC time circuit to the +12VDC backlight inverter power supply. This could turn the backlight on, say, 20 seconds after power-up.

..and off it goes!

Other than that, the floppy drive is becoming the biggest downside of Pqng design. It’s simply too unreliable and oversized in regard to other sub-modules. No idea what to use instead.

I have tried testing a selection CF-cards of different brands/sizes with no luck; the CPU module refused to detected them (or wrongly detected the size). The CPU does have a Disk-On-Chip socket, but these chips are way too expensive for this (and likely any) project. Not sure if something else could be shoehorned to the socket though..?

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