Gigatron in Shepparton Australia and detailed build info

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prodobo
Posts: 4
Joined: 26 Aug 2021, 12:17

Gigatron in Shepparton Australia and detailed build info

Post by prodobo »

Building this has really tweaked the nostalgia bone and now it's built I'm looking forward to playing around with more fundamental programming that I enjoyed so much as a youth in the early 1980's. This has been built during a COVID spike in Shepparton, Australia with a third of the population in enforced isolation. What better tonic than building one of these!!!
Below the photo I have in-depth information below to help future builders.
gigatron_prodobo1.jpg
gigatron_prodobo1.jpg (549.75 KiB) Viewed 386 times
Build experience:
The https://electronicsluckydip.com/store/gigatron.html website was a great resource. I purchased the PCB through them via eBAY with no problem. The website has a link to Mouser Australia with a bill of materials that was spot-on. With chip shortages, the ATTiny85 for 'pluggymcplugface' was unavailable but sourced around the corner in my local Jaycar store. You don't need to build 'pluggymcplugface' to get things going - see later - it gives you access via a keyboard but it's more important that you can make the gigatron talk to your PC. So... back to the build... The VGA right-angle socket was out of stock but I cobbled together a solution with a standard VGA socket again out of Jaycar. I chose to use DIL sockets for all the chips as I do like to be able to re-use components.
Gigatron ROMs are no longer available so I knew I had to burn one myself. I have a lot of kit but no EPROM programmer so I had to purchase one. I purchased a TL866II Plus from 'deal_cheaper' on eBay which distributes from Australia and it arrived in 5 days. It's labelled as an XGecu Pro and the software download URL is on the back of the unit - www.xgecu.com. The software is in English and easy to install. Now that I have this gadget, I wish I'd bought one years earlier. I love the fact that in addition to programming EPROMs it reads and programs microcontrollers as well as checking the functions of logic IC's.
To get started I loaded ROMv4.ROM from https://github.com/kervinck/gigatron-rom into the XGecu and burnt it onto the AT27C1024 ROM that came with the Mouser order - worked first time.
I followed the build instructions in the assembly manual https://gigatron.io/media/Gigatron-manual.pdf and quite enjoyed the check-points in it that allow you to test things as you go and allow you to understand the functions of the circuits as you build. The 'How it works' video at https://gigatron.io/ is very useful at this point as well.
When I switched the unit on for the first time it didn't work which raised the blood pressure a bit... It turned out the 5v USB from my powerblock couldn't drive it. There are a lot of blog entries about this so I agree - make sure you have a good 5v USB source!
I needed a retro games controller and I purchased one from electronicsluckydip via eBay who I also purchased the PCB from. This arrived fast and worked immediately. This let me know that the I/O port on the gigatron was functioning.
Adding software to the gigatron requires a working link between your computer and the gigatron. This is done by putting an Arduino-based microcontroller in the middle. If you don't know about Arduino it's a simple microcontroller with great community support - go to https://www.arduino.cc/ to find out more. You can buy them dirt-cheap out of China and compatibles are sold in Jaycar.
At this point, there is a useful tutorial at https://gigatron.io/?page_id=574 that you should follow. Given the unfortunate demise of Marcel van Kervinck the tutorial is out of date (RIP Marcel). The 'LoaderTest' Arduino .ino application link is broken. This is now known as 'Babelfish' and I had to hunt around the forum to understand that LoaderTest has been superseded by Babelfish (obvious once you know).
At this point you need to go to the https://github.com/kervinck/gigatron-ro ... /BabelFish folder (or the alternate https://github.com/kervinck/gigatron-ro ... /BabelFish folder). Ultimately I put the files in a single folder on my old laptop and compiled them via the arduino IDE. The tutorial shows you how to connect the I/O port pins to the arduino. I initially connected an Arduino UNO to test it and finished-up changing the compile destination to be a much smaller microcontroller - a compatible Arduino Nano (no code change). I wrapped the Nano in heat-shrink tubing and turned it into an interface cable between the gigatron and my PC that can be seen in my photos.
So... All done - except I don't have a working keyboard. I'm pretty sure I've programmed my ATTINY85 on the pluggymcplugface correctly but I'm awaiting the arrival of a proper, traditional PS2 keyboard. The irony is I chucked one out about a year ago... Assuming my retro keyboard purchase works, I'll let you all know which one it is!
Happy building from a fellow retro computing maniac. May the Giga Force be with you!
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bmwtcu
Posts: 57
Joined: 01 Nov 2018, 12:02

Re: Gigatron in Shepparton Australia and detailed build info

Post by bmwtcu »

Neat in-line BabelFish hack! I'm going to have to try an in-line Pluggy Reloaded now:P
monsonite
Posts: 86
Joined: 17 May 2018, 07:17

Re: Gigatron in Shepparton Australia and detailed build info

Post by monsonite »

Good work - glad you got it working.

Thanks for putting together the list of links and advice for new users. It is important that all this information can be easily located and accessed by newcomers.
prodobo
Posts: 4
Joined: 26 Aug 2021, 12:17

Re: Gigatron in Shepparton Australia and detailed build info

Post by prodobo »

I’m glad to say the Perixx Periboard-107 keyboard ordered via Amazon.com.au worked first time.
prodobo
Posts: 4
Joined: 26 Aug 2021, 12:17

Re: Gigatron in Shepparton Australia and detailed build info

Post by prodobo »

GT1 Upload: After this work was completed, I was still not sure how to upload .gt1 images. Part of my problem is I'm an old-school programmer and know C, C++, C# but have no knowledge of Python. The easiest tool (as I understand it) to upload .gt1 files is the utility sendFile.py. See
https://github.com/kervinck/gigatron-ro ... ster/Utils. For non-Python users on a Windows PC, basically this means you need to download and install Python https://www.python.org/downloads/windows/ and after installed, you can run python .py scripts like executables. You run a command prompt (cmd) and from the prompt run a command like 'sendfile.py invader.gt1'.
In my case, I have hooked up my Arduino Nano between the PC and Gigatron with the babelfish code installed as you can see in the photos above. sendfile.py handles all the comms between the PC and the gigatron to reset the Gigatron and upload your .gt1 software.
at67
Posts: 389
Joined: 14 May 2018, 08:29

Re: Gigatron in Shepparton Australia and detailed build info

Post by at67 »

You can upload, (.gt1, .gtbas, .vasm, .gasm, .gtb, .gcl), to real Gigatron hardware through any of the BabelFish supported Arduino's using my emulator as well, (you just need to configure the loader_config.ini file).

Left mouse click in the browser loads in the emulator, right mouse click uploads to Gigatron, (CTRL + H for help).

P.S. You don't need to install anything, (Python etc, unless you want to upload .gcl files).
prodobo
Posts: 4
Joined: 26 Aug 2021, 12:17

Re: Gigatron in Shepparton Australia and detailed build info

Post by prodobo »

Thanks at67 :-)
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