DosFox

I saw my favourite words.
"Schematics are available"

https://tumbleweed.nu/lm-3/schematics.html

LM-3 --- MIT CADR schematics

Mar 21 at 11:06pmWeb
Show threadDosFox5d ago

So somehow I've ended up on a bit of a rabbit hole.

Schematics for the MIT CADR LISP machine are available, and in fact there's already an FPGA implementation!

https://tumbleweed.nu/r/uhdl/doc/trunk/README.md

uhdl: Documentation

Show threadDosFox5d ago

That said the target FPGAs are a bit... Unusual.

Either a pipistrello board (a xilinx Spartan 6) or an Arty S7 (Artix-7).

Maybe something that could be ported to a Tang FPGA?

Show threadDosFox5d ago

There's also the other temptation.
If we have schematics, and assuming that the FPGA implementation includes the necessary microcode and ROMs, could we build new CADRs?

They appear to be fully TTL - without any PALs or custom ICs. Although some ICs may be hard to come across.

Show threadFlux5d ago
@DosFox I have an Arty S7-25. It's a pretty standard Xilinx board. Though open source toolchain support still isn't there for XC7.
Show threadDosFox5d ago
@WillFlux am I accidentally influencing a lot of people with FPGA Dev boards to try and run this 😅
Show threadHenning Paul DC4HP5d ago
@DosFox The Gowin FPGAs are the exotic ones. Spartan-6 and Artix-7 are so much middle-of-the-road, it couldn't get more common.
You can't imagine how widespread Xilinx FPGAs are in the industry.
Show threadDosFox5d ago
@hennichodernich cheap though!
Show threadjoshie 🏳️‍🌈5d ago

@DosFox oooh  

might have to dig out my xilinx kit

Show threadDosFox5d ago

@6a62 I have an Arty S7 *somewhere* that was pulled out of a prototype printer.

I may as well 👀👀👀