Build Your Own FPGA (2012)

Don't miss the gem in the comments...someone answers this question there:

"Hi. Is possible use this like a "industrial" fpga? For example, for minning bitcoin? Because the fpga is very expensive here in Brazil, and the 7400 is cheap. "

I love the idea of this! It reminds me of the megaprocessor project[1] but much more accessible in its scale, and way easier to understand.

The writeup is very clear, and the boards themselves are very easy to follow in operation. The more I think about it, the more I feel the need for a wall sized array of them acting as a clock. Maybe with a flipdot display for the time? The main issue I see is that the busses are pretty narrow and the there isn't a dedicated crossbar for the routing so the placement is going to be really challenging and probably involve a lot of 'inactive' modules that are just acting as a passthrough for the wiring.

[1]http://megaprocessor.com/

Hm, this makes me wonder, are there any hand-assembled TTL computers that can send UDP packets on the internet? ChaCha20 is easy enough to implement and simple enough that you could probably do encrypted chat between two almost-definitely-not-backdoored computers if so.

EDIT: though, I supposed you don't need your NIC to be trusted any more than your ISP's router, so an esp8266 might be sufficient.

Perhaps someone can design an FPGA and have it fabbed by Google for free! See: [1]

[1] https://news.ycombinator.com/item?id=23755693

Another open FPGA project:

https://github.com/haojunliu/OpenFPGA https://www.eecs.berkeley.edu/Pubs/TechRpts/2014/EECS-2014-4...

I like this. Real FPGAs use the same realization of an n-input LUT as a 2^n bit shift register plus a mux, which is why e.g. Xilinx lets you have an SRL16 for the same cost as a LUT4--the shift register is primarily intended to hold the LUT configuration bitstream, but you can repurpose it as user logic.

The form factor kinda reminds me of mostly misguided project I toyed with in early 00's. The idea was to get useful amount of computing power for massively parallel applications on shoestring budget by building 2D network of boards in this form factor that either contained “8051 on steroids” MCU or small-ish Altera CPLD.

If curious see also

2017 https://news.ycombinator.com/item?id=14643474

Discussed at the time: https://news.ycombinator.com/item?id=4726724

The circuit board modules that make up the cells of the FPGA are reminiscent of PLC's.

https://en.wikipedia.org/wiki/Programmable_logic_controller

This is a blog post from 2012, which should be noted in the title of the HN discussion by appending "[2012]".