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Another Gigatron is alive!

Posted: 01 Apr 2020, 19:07
by Dave

I recently finished building the Gigatron kit and am pleased to report that it worked on first power-on. The kit was a pleasure to build.

I was particularly impressed with the PCB, how well marked and laid out it is, and how easy it was to solder. Whomever is manufacturing the PCB does a really good job. I found the Pluggy McPlugface PCB a little harder to solder than the Gigatron PCB, perhaps because the pads are smaller.

I had a little trouble getting my USB keyboard to work via Pluggy McPlugface. I'll write another post about what I learned.

Congratulations to Walter and Marcel on designing the Gigatron and on putting together a wonderful kit.

Dave MacKay
near Toronto, Canada

Re: Another Gigatron is alive!

Posted: 02 Apr 2020, 05:59
by marcelk
Thanks for the image, I collect those...

You mentioned that the keyboard wasn't working at first. In the photo it clearly works. Some keyboards have trouble booting (and a few won't boot at all, not even after 1 minute of trying). See also viewtopic.php?p=381#p381 Did you try a different keyboard here, or found something else?

Re: Another Gigatron is alive!

Posted: 02 Apr 2020, 20:05
by Dave
Hi Marcel, Thanks for the reply and for putting together such a great project.

Yes, I looked at that post and a couple of others as I tried to figure out the problem I was having with my keyboard.

I was trying to connect a USB keyboard to the Gigatron via Pluggy McPlugface and a PS2-to-USB adapter. The keyboard, which works fine on my Raspberry Pi, had troubles connecting to the Gigatron. Sometimes it would be recognized almost immediately (in less than 10 second), sometimes it would take 20-50 seconds, but most of the time it wouldn't connect at all.

The power supply was rated for 5V and 3A. The Gigatron, with Pluggy McPlugface and the keyboard was drawing between 90 and 100 mA and the voltage was steady at 5.04V. That gave me confidence that the power supply wasn't the problem.

The game controller worked perfectly every time, so that I had some confidence that Pluggy McPlugface was working.(I ordered a second Pluggy McPlugface just in case, but it hasn't arrived yet).

I was using a green PS2-to-USB adapter. Because that was intended for use with a mouse, I was concerned that it might not be wired to permit it to work with a keyboard (PS2-to-USB adapters for keyboards are purple in colour). I got a purple (keyboard) adapter but the problem remained. I traced how the green (mouse) and purple (keyboard) adapters were wired and found that they are electrically identical.

I sourced a Perixx Periboard-409 PS2 keyboard from Amazon. It worked perfectly as soon as I connected it.

I concluded that my USB keyboard (a Verbatim 99201) just wasn't well suited to work with PS2. It was, after all a USB keyboard. There was very little technical information about the keyboard on Verbatim's website and nothing at all about using it with a PS2 adapter.

Re: Another Gigatron is alive!

Posted: 03 Apr 2020, 20:27
by DavidHK
It sounds very similar to the problems I have with my PS/2 keyboard, quite often it is not working at all and I have to restart everything. I suspect it really is the power supply, at least I get the impression that my chances are different depending on my supply. I guess that some keyboards just draw a surge at the start and when the voltage drops too much they switch off. But I haven't done enough experiments to validate those guesses.