Robert Butler @roberttheiv@mastodon.social
I’m a programmer turned homebrew computer maker.
Joined Mar 2020
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I’m designing and building 16-bit homebrew computers from the instruction set to the desktop. The most fun you will ever have with a computer is the one you built yourself. GrokThis on YouTube: https://www.youtube.com/channel/UCh4OpfF7T7UtezGejRTLxCw
Advent of Code: solution spoiler
I had a terrible time getting yesterday’s advent of code working correctly in uCISC. Not having string utilities that handle the inconsistent line endings invisibly was a challenge. 18 out of 1000+ lines were different in a way that mattered.
One of the problems I’m having with the advent of code on uCISC is that I can’t run it on my real processor. The input text is larger than the 8k of memory I have on the FPGA. I might have to break out my larger FPGA and see if I can get uCISC running on it with a full 64k. Running on real hardware is better 😁
Robert Butler
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#adventofcode in Mu
Day 3 solutions (spoiler alert):
http://akkartik.github.io/mu/html/apps/advent2020/3b.mu.html
60 minutes. Lost 11 minutes debugging a silly mistake (see commit log)
No new Mu bugs found, no machine-code hacking was needed.
Project page: https://github.com/akkartik/mu
Advent of code in uCISC: Day 3 - https://github.com/grokthis/ucisc/blob/master/examples/aoc/2020/day_3.ucisc
25 minutes for part 1 and 5 minutes to run for part 2. Had all the standard libs I needed this time around unlike day 1 and 2.
Robert Butler
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*Advent of code in Mu*
Day 2 solutions (spoiler alert):
http://akkartik.github.io/mu/html/apps/advent2020/2a.mu.html
http://akkartik.github.io/mu/html/apps/advent2020/2b.mu.html
40 minutes. No new Mu bugs found, no machine-code hacking was needed.
Project page: https://github.com/akkartik/mu
Robert Butler
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Robert Butler
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FORTH is running with a working screen editor!
Robert Butler
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The note that prompted me to experiment
Well... composing that inspired me with an idea. Found the issue and just correctly calculated fib(24) at 8 MHz on uCISC hardware.
Robert Butler
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@s_ol @roberttheiv I just remembered to do something overdue: add your projects to Mu's list of forks:
https://github.com/akkartik/mu#forks
Let me know if you'd like any changes to the blurbs or your credits!
Months of work to get a mostly working uCISC processor. Attempt 7-ish looks like it’s going to finally work. Passing a few dozen tests written in uCISC so far. If I can just isolate another hardware bug or two, Fibonacci is next.
Robert Butler
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The Mu shell, compiling down to a subset of 32-bit x86 machine code, then to a Linux ELF binary, packaged up with just a Linux kernel and nothing else, running on a Linux console emulated on Qemu, on a Thinkpad T420s running 64-bit Linux.
Just another 27 million lines of C to take out (Linux kernel), and I'll have a decent computing stack.
Robert Butler
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*Screenception*
Visualizing programs with side-effects in a postfix shell with a live-updating text-mode environment. Built all the way up from machine code without any dependencies (except an x86 processor and Linux kernel).
https://archive.org/details/akkartik-2min-2020-11-12
Project page: https://github.com/akkartik/mu
More context: https://mastodon.social/@akkartik/104896128141863951
Just got UART half working (Tx, no Rx yet) on uCISC processor. Sending a stream of asterisks to my desktop computer at 9600 baud. Have a few bugs still to work out, but I’m so close to being able to send messages back and forth to my processor.
Robert Butler
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Just checking the health of the microcontroller. The speed is 9600, I did not come across this fact in the instructions for the firmware :)
You can’t tell from the photo, but this is a knight rider like animation on the blue and yellow LEDs. The red LEDs are the program counter (of little use at full speed).
uCISC is officially implemented in hardware now. Here is a LED animation demo written in the uCISC language running on the first ever working uCISC processor developed in verilog and running on a TinyFPGA Bx board at 8MHz.
Robert Butler
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Am I the only one who possesses really old hardware, yet don't dare to plug it in anymore, because I'm afraid I might be really disappointed by finding out it's now broken?
Schrödinger's Retro Computers...
Robert Butler
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@theruran @thegibson when you think about it, the reason that www came to dominate the internet may have been as simple as the fact that it became a much easier way to distribute and update applications, which has little to do with what the web was designed for.
In the end, it’s the browser-as-terminal that allowed us to give-up the freedom of personal computers for the convenience of the mainframe known as “the cloud”.
Time to take the power back.
Robert Butler
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It's interesting to think that jurrasic park was made on a computer that probably isn't powerful enough to watch jurrasic park on youtube
I’m a programmer turned homebrew computer maker.
Joined Mar 2020
