MyCPU – Homebrew Computer from Discrete Logic Gates • Hacker News Board

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#31

Post by CrLf » Thu, May 16, 2019, 6:22 PM UTC

illys wrote: post #5

Amazing! A computer made without microprocessor... or a processor made of TTL circuits. He has remade a system similar to the core of the great 1970's Xerox Alto / Xerox Star series :-) I never thought someone would remake a processor this way. I love that kind of madness ! [edit: use the site backup if it fails to load: http://mycpu.thtec.org/www-mycpu-eu/index1.htm ]

Walter Belgers and Marcel van Kervinck's Gigatron (https://gigatron.io/) is also interesting. It's spirit is to use only 70's technology to keep the system "learnable" from the ground up, although they sometimes violate this rule for peripherals outside the main system.

Walter gave a talk recently about it: https://www.youtube.com/watch?v=rbaAmnhZAis

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#32

Post by earenndil » Thu, May 16, 2019, 6:31 PM UTC

See also: homebrewcpu https://www.homebrewcpu.com/ and megaprocessor http://www.megaprocessor.com/

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#33

Post by KC8ZKF » Thu, May 16, 2019, 7:38 PM UTC

All those fancy-pants semiconductors...

Here’s a real computer. http://web.cecs.pdx.edu/~harry/Relay/

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#34

Post by mutac » Thu, May 16, 2019, 8:14 PM UTC

KC8ZKF wrote: post #33

All those fancy-pants semiconductors... Here’s a real computer. http://web.cecs.pdx.edu/~harry/Relay/

I took a compilers course from Prof. Porter, and at the time he invited undergraduates to write a simulator for his relay computer. I remember thinking, "why in the world would I want to do that? I want to work on the next big thing!" Fast forward to now, I've never worked on the Next Big Thing, and am instead slowly, though enjoyably, building Ben Eater's 8-bit SAP-1 when I have some free time. It sort of feels a bit like building a ship in a bottle. I just wish I had taken Professor Porter up on his offer and maybe scratched an itch when I had a little more energy and free time.

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#35

Post by gcb0 » Thu, May 16, 2019, 8:20 PM UTC

AnIdiotOnTheNet wrote: post #15

This is definitely on my "list of things I've always wanted to do but I realized man is mortal and I have to prioritize". I'm a personal computing enthusiast and it doesn't get much more personal than designing and building your own architecture.

not to mention the $50~200k on specialized test equipment you will have to buy to even start on this path.

Nobody mentions this.

In every wire rat nest CPU picture, there is always several thousand dollars of digilent and HP gear out of the frame.

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#36

Post by jhallenworld » Thu, May 16, 2019, 9:31 PM UTC

KC8ZKF wrote: post #33

All those fancy-pants semiconductors... Here’s a real computer. http://web.cecs.pdx.edu/~harry/Relay/

You can now buy one:

http://relaysbc.sourceforge.net/

(apologies for the self promotion..)

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#37

Post by vhodges » Thu, May 16, 2019, 9:39 PM UTC

jhallenworld wrote: post #36

KC8ZKF wrote: post #33

All those fancy-pants semiconductors... Here’s a real computer. http://web.cecs.pdx.edu/~harry/Relay/

You can now buy one: http://relaysbc.sourceforge.net/ (apologies for the self promotion..)

I have been looking at your board on Tindie! Alas, I don't think it should be my first major soldering job (if you don't count the board I stuffed 25 odd years ago that my friend had to fix for me)

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#38

Post by bogomipz » Thu, May 16, 2019, 10:05 PM UTC

I'm curious does anyone know what the last substantial commercial computer that shipped with CPUs made out of discreet logic chips like this was?

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#39

Post by musicale » Thu, May 16, 2019, 11:44 PM UTC

I love these homebrew CPU projects. I saw one one in person and was amazed (and impressed by the insane dedication as well as the madness of wire-wrapping 1970s-era TTL components into a CPU) - then a year later I saw two of them!! Then I saw a third.

I believe the first two I saw were MAGIC-1 and BMOW (Big Mess o'Wires). I also really liked the MOnSter 6502, a beautiful board-level reimplementation of the 6502 in surface-mount discrete components, with LEDs on the data lines and optional slow/single-step clocking.

Also relevant: the nand2tetris.org course, and Niklaus Wirth's TRM/RISC-3 (not to be confused with Berkeley RISC-I or modern RISC-V) FPGA implementation. Notably TRM/RISC-3 is incredibly simple but can run the whole Oberon system.

In the modern era, I think FPGAs are the killer platform for computer architecture experimentation. There are multiple free MIPS implementations for FPGA and of course there is great OS/compiler support for MIPS.

Re: MyCPU – Homebrew Computer from Discrete Logic Gates

#40

Post by mycall » Fri, May 17, 2019, 1:49 AM UTC

varjag wrote: post #20

vhodges wrote: post #17

Earlier quoted context omitted.

:) There are many (it's a thing): https://hackaday.io/projects?tag=CPU (Some are FPGA, most are TTL) Including two risc-v implementations (one seems stalled): https://hackaday.io/project/18491-worlds-first-32bit-homebre... (No activity for a while now) and https://www.youtube.com/playlist?list=PLEeZWGE3PwbansoxKjjMK... One I am particularly interested in is the Gigatron: https://hackaday.io/search?term=Gigatron&categ…

http://www.homebrewcpu.com/ is wire wrap 16 bit computer that in fact serves the web pages and has telnet access.

omg, Homebuilt CPUs WebRing still working.