Search found 52 matches

by bmwtcu
01 Aug 2021, 17:31
Forum: Kit assembly gallery
Topic: My Gigatron build
Replies: 5
Views: 188

Re: My Gigatron build

The audio DAC is an R2R resistor ladder and isn't a simple resistor array, but you can literally copy the symbol on the Gigatron schematic and build one from 10k/20k resistors. In my experience, unactivated flux is conductive, so perhaps that was the original problem you had.
by bmwtcu
29 Jul 2021, 20:07
Forum: Hardware and software hacking
Topic: Pluggy Reloaded
Replies: 138
Views: 48790

Re: Pluggy Reloaded

@at67 I think he's using the NOROM BabelFish which should work with the v5a ROM. @wbushby Do you have a way to measure voltage/current on 5V? From your description, I'm suspecting that your 5V rail droops to <4.5V when you're accessing the SDCard and causes your reset chip to kick in. Either that or...
by bmwtcu
29 Jul 2021, 09:04
Forum: Hardware and software hacking
Topic: Pluggy Reloaded
Replies: 138
Views: 48790

Re: Pluggy Reloaded

Is the SD card formatted to FAT16/32? Did you already check for shorts on the SDCard adapter/Pro Micro SPI pins? What version ROM and BabelFish are you using? See viewtopic.php?f=4&t=279 for valid combinations and where to get them. Where is the jumper you are referring to?
by bmwtcu
18 Jul 2021, 23:50
Forum: Hardware and software hacking
Topic: tutorial about programming ATTINY85 with Arduino Nano
Replies: 6
Views: 207

Re: tutorial about programming ATTINY85 with Arduino Nano

https://circuitdigest.com/microcontroller-projects/programming-attiny85-microcontroller-ic-using-arduino https://github.com/kervinck/gigatron-rom/blob/master/Utils/BabelFish/BabelFish.ATtiny85_fuses.txt Googled these, but haven't tried it myself. I highly recommend checking out norgate's Pluggy Relo...
by bmwtcu
01 Jun 2021, 11:15
Forum: Hardware and software hacking
Topic: Gigatron on an FPGA
Replies: 10
Views: 4547

Re: Gigatron on an FPGA

I don't think he/she has ever logged back in since that single post for this thread. Are you talking about the image not scrolling fully to the left and getting stuck? It sounds like the Jupiter issue that I encountered with ROMv3 back in 2019. Like you it only affected "Pictures" and all other grap...
by bmwtcu
29 May 2021, 17:58
Forum: Hardware and software hacking
Topic: Possible ways of speeding up the Gigatron
Replies: 32
Views: 2601

Re: Possible ways of speeding up the Gigatron

If you extend out to the first of the PC parts on the right of the Expander card, you could theoretically design a single board to interface to the RAM/A15/PC3 reset/Output register without bodge wires if you install a female header at A15. Not sure how the mechanical tolerances work out though.
by bmwtcu
19 May 2021, 13:31
Forum: Hardware and software hacking
Topic: Possible ways of speeding up the Gigatron
Replies: 32
Views: 2601

Re: Possible ways of speeding up the Gigatron

More recent CPLDs are much more powerful. They could hold the whole gigatron. One issue is that few of them are 5v tolerant. Unfortunately, there have not been any 5V tolerant CPLD/FPGA designs from the major players for almost 2 decades at this point. Just out of curiosity, what are you using to c...
by bmwtcu
12 Apr 2021, 14:30
Forum: Escape Meta Alt Control Shift
Topic: Gigatron ASIC and the Gametron Handheld
Replies: 28
Views: 7611

Re: Gigatron ASIC and the Gametron Handheld

WhatsApp Image 2021-04-12 at 9.49.50 AM.jpeg Current state of the FPGA breakout board bringup. The video on the display is rotated 90 degrees and I'm currently hunting down the datasheet. If anyone has a Panelook account and can help me download it, it's the Epson 2.8'' L4S00242P00 (https://www.pan...
by bmwtcu
28 Feb 2021, 14:28
Forum: Kit assembly gallery
Topic: And again a new Gigatron fan
Replies: 11
Views: 1801

Re: And again a new Gigatron fan

Welcome Hans! Nice work! "soldering is relaxation for me" - I totally get it! It's exactly the same situation for me. Nothing beats the leaded solder fume high:P Doubling the clock in hardware is the easy part. The VGA timing is tied to instruction count, and deviating from the current architecture ...