What else have I been up to?

So, other than converting my CoCo to NTSC, I have been working on a while bunch of smaller projects, before and after.

GBS Control Case

I decided to put the GBS Control in a “real” case. To that end, I literally photocopied the base of the GBS Control, imported the image into CorelDraw, and started designing up a case.

Didn’t take me too long to have something presentable together, with all the features from the previous case (On / off switch, LED, power jack) all preserved, but now in a proper shell. This was cut from some surplus frosted acrylic I had on hand. I made one mistake, but was able to correct that in post production, and I’m very happy with the outcome!

I’m tempted to make a second one, as I keep finding uses for them.

Here it is converting the output from my TI 99/4a across to VGA.

EDIT: Here’s the V2 version of this shell, in PDF and DXF. CC BY SA

Super Nintendo Entertainment System

I saw a local ad for a very cheap SNES, which I jumped on with some gusto. Turns out I knew the seller, which was a nice coincidence.

I zipped out and also picked up a cheap controller and the cheapest second hand SNES cartridge I could lay my hands on.

When I got it home, it didn’t actually work, at first. It took me a while to realise that both the video cable and the power supply cable were damaged.

I chucked the video cable away, as I also had a suitable cable. Turns out it uses the same cable as the Nintendo 64, and I have upgraded my N64 video cable. Now I had video, it was time to turn my attention to the cable for the power.

Using the big box of “I void warranties” bits, I whipped the two halves of the power supply apart. I found some suitable cord, and, with a bit of effort, I was able to install the new cable in the strain relief, and solder it to the transformer inside the shell.

Transformers: More than meets the, oh wait, no.

Unfortunately, I was not able to find a suitable plug in my collection, so checking the fault wasn’t in the first 10 CM of cable, I snipped off the cable and connector from the old cable and soldered it on to the new cable.

(I forgot to put on heatshring for an outer layer, so ended up redoing the whole thing again later)

Yes, I ran Chrono Trigger. It works fine. This cart won’t emulate any custom chips, but for now it’s fine.

This got me booting, and I have ordered, and recieved, a generic “800 in 1” cartridge for the system. Many games will now be played.

BBC Model B

The power supply in this had started making an arcing noise. Never something to make me happy. I ordered a Meanwell power supply of a suitable size and simply did an innards swap of the existing power supply. This took longer than planned becasue, well, I ordered the wrong power supply the first time. Not to worry. I can use that one to replace the PSU in my Atari STe, which needs a new PSU.

Oddly I failed to get any photos of this work.

The Beeb is now booting, and I have moved the ROM for the SD Card adaper, and the adapter itself across to this system. Repton was played.

It boots, doesn’t make arcing noises and happily plays games.

5V 5A Power Supply

I had a big chunky 5V power supply that I wanted to use to power a system, except it had failed. Symptoms were the power LED was blinking.

Bulgy caps are bulgy. They’d also eaten through the glue underneath. That got washed.

Opening it up revealed two primary capacitors were bulging badly. Taking a punt, I purchased some Low ESR replacements, and it came good! I have earmarked it for the Omega MSX.

AV Setup

I had to move all the AV gear out of our living room, and then back in, as part of some setup for work being done at our house. I used this as an excuse to re-cable and consolidate all the consoles. I had to make up this monstrosity because, while the TV has a separate audio in for each type of video signal, my switcher puts out one audio source, and switches the video. This just connects all 3 inputs to one output.

1 audio input, 3 audio outputs. I call it “The Abomination”.
Yes, that’s a lot of consoles. I agree.
Everything tucked away. All I need to do now is squeeze in the 7800, and get a PC Engine.

Spectrum 48k

Another quick job here. I took it out of the fancy dk’tronics mechanical case and fitted it into a new Spectrum 48k case, complete with new membrane. I used the original keys and aluminium shell, mostly because I forgot to order a replacement aluminium shell :-)

Looks a lot better like this IMO, and it work perfectly as a “base” spectrum.

A few scratches and dings, but that’s history!

Harlequin 128k

What did I do with the dk’tronics case, you might ask? Well, I also received a kit Harlequin 128k from Byte Delight to build up. It ended up taking me under a day total, and it worked the very first try.

Parts! And baggies!

This kit is amazing! Every component I could need for any configuration was included, which means I had leftover components. Every single item was in an individual ziplock baggie, with a clearly printed label on the front, as well as a step number (To go with the instructions). They were even packed in the order they needed to be assembled.

Resistors and sockets in.

The instructions were clear and well documented, with plenty of “Do this here” and “If you can’t find this component, it’s next to that component” type notes scattered throughout. There were special sections just to cover specific options and plenty of illustrations and schematics.

It truly was an easy build.

Everything in. Just need to add the ICs now.

There was exactly one socket that threw me, and that was because it was backwards to the other sockets.The only other thing that was remotely difficult that I hit was I had chosen to roll my own ROM, and the system came with a lot of powerful options for the ROM, so it took me a little time to get everything right. Once that was done, it literally booted first time.

Ready to case…

I also ended up making up the RGB cable, and the video out is so crisp and nice! It calls out to me to play games on it! (The RGB isn’t compatible with my 15KHz monitor, but work perfectly with the GBS Control)

Doesn’t that look snazzy?

Atari 7800

Thanks to a trade of my spare TI 99/4a, I was able to get an Atari 7800. (Thanks Shane!) It had already been modded for AV so one less thing I had to do. I must admit, the picture quality from the 7800 gets a bad rep for a reason. Down the track, I’ll probably fit a UAV mod and get SVideo out of it.

I did need to make up a power connector for it. It uses a completely non standard 2 pin connector. My solution was to drill out the shroud from a standard DuPont connector, widen the crimps slightly and then glue on a small section of plastic to preserve polarity. I then attached it to a standard barrel socket. Works a treat.

7800 Controllers

I also received a box of old, dirty 7800 controllers. I gave them all a “once over” with a wet cloth and some detergent before going through the pile.

Two were clearly damaged. One had a button missing and the other had the d-pad at a “jaunty” angle. This one also had the second button permanently stuck down.

I put aside the two obviously damaged ones and went through the rest. Two were fine “out of the box” so I just gave them an extra scrub and put them in my box of goodies.

The next one had no life from the fire buttons, so I put it in the pile of damaged controllers. The fourth one had no life from the left d-pad direction. In it went to the pile of damaged controllers.

I then returned to the damaged pile, starting with the controller with the missing button. Unfortunately, the screws were extremely rusted, and three of them stripped the heads while I tried, unsuccessfully, to remove the screws. I ended up drilling out the screws, and got all but one of them out of the holes. I soaked the rest of the screws for the rest of the controllers in WD40 for 15 minutes, and had no problems from then on out.

The controller with a bad left d-pad responded fine after some TLC and some cleaning of the contacts, but it has since started acting up again. I’ll need to investigate further. It works, just not reliably. I will need to revisit it later.

BTW I clean the contacts on the PCB side with isopropanol, and in extreme cases, with an ink eraser. On the rubber side, I gently wipe them on a piece if paper. This takes of a smidgin of the conductive carbon surface, exposing fresh carbon. It can help a lot.

I was quickly able to build a complete controller out of a combination of the “jaunty” controller and the one with the missing button. The jauntiness seems to come from someone cutting off the tabs on the d-pad. No idea why they would do that…

At this point I had 4 of the 6 working, and was feeling pretty gung-ho. Let’s see what we can do with number 5, eh?

Normally when you have a problem with a joystick like this, with a direction or button completely not working, It’s a simple fix. Replace the joystick cable. I even had an extension cable in stock for exactly this scenario. I cut the socket end off it (Saving it for later) and stripped back and soldered in the cable.

The joystick didn’t work. In fact, the system was registering random movements. Not good.

Busting out the multimeter, it turns out this extension cable may have the right colours, but none of them correspond to the right pins on the connector!

OK let’s fix that up.

And while directions are working again, we still don’t have fire buttons.

I go on like this for ages. I check the resistors in the controllers. I check the cabling, 3 different times. I even put the original cable back in. No fire buttons.

In exasperation, I start probing around in Resistance mode on my multimeter. Resistance between the connector end and the solder joint on the inside of the joystick is “0.7 Ω” so that’s fine. I then, as an act of desperation, start measuring resistance around the PCB itself. It’s all looking fine until suddenly, there’s infinite resistance between the solder joint and one of the contact pads the fire buttons use.

What?

I scratch back some solder mask and check again. Looks like I have connectivity up to about half way down the trace and then… nothing. Visual inspection, even under the magnifying glass reveals… nothing.

What. The. Heck?

In the end , I just scraped back all the solder mask along that track, then flowed a healthy trace of solder down it, then covered it in nail polish to stop oxidization.

One track blobbed over. I covered it with garish purple nail polish next.

That one works too now.


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Comments

5 responses to “What else have I been up to?”

  1. Greg Howell Avatar

    Great post! The Harlequin 128 looks very neat.

    1. Cheshy Chesh Avatar
      Cheshy Chesh

      It was a lovely kit to work on. Really nice board and plenty of simple soldering.

  2. Christian Avatar
    Christian

    Any chance of you sharing the case files? I have one 3d printed shell but with time it ends up cracking.

    1. Cheshy Chesh Avatar
      Cheshy Chesh

      No worries at all! I’ll update the article with them as DXF and PDF.

      1. Christian Avatar
        Christian

        Thanks! Really apreciate it!

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