Read this if you need assistance building your Gigatron kit

A place to eternalise your Gigatron build photos. From box to BASIC.
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marcelk
Posts: 469
Joined: 13 May 2018, 08:26

Read this if you need assistance building your Gigatron kit

Post by marcelk » 16 Sep 2019, 14:05

By now, hundreds of enthousiasts have successfully built the kit, and we feel that all things that might possibly cause problems are well known. In case you need assistance, it's advised to first go through the tips and tricks on the Troubleshooting web page. We feel the information there is as good as complete now. Still, we do get the occasional support request for things that are explained there... (The good news is that support requests pop up for far under 5% of the kits out there!)

In the unfortunate case that none of that helps, and if you would like assistance, the best next step is to contact us on the support e-mail address as listed in the assembly manual. In your mail, describe exactly what building step you're at, what you're experiencing and what you expected instead. Include the detailed photos that the manual asks for. Explain what items from the Troubleshooting page you tried and what the results were. Please be specific and complete, don't just summarise. Make a video if that helps explain what you see. With a complete story, we can usually find a resolution over e-mail rather quickly, and otherwise we can make a detailed plan with you.

vmsh0
Posts: 2
Joined: 20 Feb 2020, 00:16

Oh no! my Gigatron doesn't work :(

Post by vmsh0 » 20 Feb 2020, 09:52

Hi!

I finally finished assembling my kit that I had gotten back in 2018.

Unfortunately, I apparently got something wrong, since it doesn't run :lol: the blinkenlights don't show the correct pattern and are stuck, but the power led is on and stable. Oscilloscope also confirms the power line is stable.

Components are placed correctly, and solder joints all look fine. I did some preliminary tests with an oscilloscope and a logic analyzer and weirdly, it seems that the clock is running at 250kHz. I don't know why that's the case. However, it cannot be the only issue as I believe the Gigatron should still run fine at that frequency.

I'm going to test each pin connection with a multimeter later today using the excel sheet you provide. I hope I will find a broken connection, easy fix!

Otherwise, what would my next debugging steps be? I was thinking of testing individual parts, first of all seeing if the program counter counts up, then test diode decoders, the ALU, etc. Do you have any practical advice on how to do that? I'm not really used to this kind of hardware hacking! And I can't wait to begin hacking on it :D

cmpxchg
Posts: 8
Joined: 07 Jun 2019, 11:44

Re: Oh no! my Gigatron doesn't work :(

Post by cmpxchg » 20 Feb 2020, 10:40

Debugging hardware order:
power, reset, clock.

Power:
Using a short USB-minicable and IKEA koppla powersupply.
More hints @ https://gigatron.io/?page_id=880

Reset: U2 pin 1, should be low and then high and power led D2

Clock:
If it's 250 kHz it is way too slow, should be 6.25 MHz, is it a square clock, within the bandwidth of your probe/scope ?
Probe the buffered clock U1 pin 12, and cleanup circuit around crystal.

Schematic https://cdn.hackaday.io/files/207818890 ... matics.pdf

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marcelk
Posts: 469
Joined: 13 May 2018, 08:26

Read this if you need assistance building your Gigatron kit

Post by marcelk » 20 Feb 2020, 11:14

Just contact us by e-mail though the address listed in the assembly manual.
marcelk wrote:
16 Sep 2019, 14:05
In the unfortunate case that none of that helps, and if you would like assistance, the best next step is to contact us on the support e-mail address as listed in the assembly manual. In your mail, describe exactly what building step you're at, what you're experiencing and what you expected instead. Include the detailed photos that the manual asks for. Explain what items from the Troubleshooting page you tried and what the results were. Please be specific and complete, don't just summarise. Make a video if that helps explain what you see. With a complete story, we can usually find a resolution over e-mail rather quickly, and otherwise we can make a detailed plan with you.

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