from Hacker News

MOnSter 6502: a working transistor-scale replica of the classic MOS 6502

by harporoeder on 4/3/24, 7:31 PM with 86 comments

• by dang on 4/3/24, 9:39 PM

  Related. Others?

  Complete working transistor-scale replica of the classic MOS6502 microprocessor - https://news.ycombinator.com/item?id=33841901 - Dec 2022 (38 comments)

  MOnSter 6502 - https://news.ycombinator.com/item?id=26507525 - March 2021 (31 comments)

  The MOnSter 6502: transistor-scale replica of classic MOS 6502 microprocessor - https://news.ycombinator.com/item?id=17969472 - Sept 2018 (81 comments)

  A working, transistor-scale replica of the MOS 6502 microprocessor - https://news.ycombinator.com/item?id=14386413 - May 2017 (44 comments)

  The MOnSter 6502 - https://news.ycombinator.com/item?id=11703596 - May 2016 (74 comments)

• by ooterness on 4/3/24, 8:57 PM

  I love this art/engineering project. The whole concept of extra-large unintegrated circuits is just so amusing.

  The team behind this project sells kits for two classic ICs, the 741 op-amp [1] and the 555 timer [2]. Sadly, they've said the Monster6502 is too big and complex to make a practical kit.

  [1] https://shop.evilmadscientist.com/tinykitlist/762 [2] https://shop.evilmadscientist.com/tinykitlist/652

• by tombert on 4/3/24, 8:24 PM

  Wait, so if I understand this correctly (what I don't know about hardware is a lot!), is this basically a "macroprocessor"? As in, it functions the same way as a vanilla 6502, but done at a larger scale?

  Actually pretty cool that it's able to get 1/20th the speed when it's this big!

• by lloeki on 4/4/24, 6:15 AM

  > Does it run at the full speed of an original 6502 chip?

  > No; it's relatively slow. The MOnSter 6502 runs at about 1/20th the speed of the original, thanks to the much larger capacitance of the design. The maximum reliable clock rate is around 50 kHz. The primary limit to the clock speed is the gate capacitance of the MOSFETs that we are using, which is much larger than the capacitance of the MOSFETs on an original 6502 die.

  Now I'm curious but in way over my head.

  Could the speed be improved by using MOSFETs with better capacitance?

  Can the full 1.023 Mhz be attained by throwing money at it or are there physical limitations at that scale?

• by pnw on 4/3/24, 9:22 PM

  I signed up for the mailing list when it was first on HN a few years ago, but haven't seen many signs of progress. Website still says mid 2023 for a launch.

  6502 was my first CPU so I'm totally down to buy one, even though it's going to be pretty expensive. I'd be pleased if they could make them for less than $5k.

• by cancerhacker on 4/3/24, 11:49 PM

  It’s mentioned in the page, but the emulation at http://www.visual6502.org/JSSim/expert.html is worth a visit.

• by th4tg41 on 4/3/24, 10:35 PM

  Wonder if it's feasable and how much work it would be to record a run of eg Super Mario Land and play the processor instructions back on this thing hanging on the wall. Would be a nice conversation piece.

• by henry_bone on 4/3/24, 10:35 PM

  I wonder if it's correct right down to the errata. Was there undocumented instructions on the 6502? If so, I wonder if it supports those.

• by jpl56 on 4/5/24, 3:37 PM

  Great project! Ben Eater needs this in his videos, he would show us how the registers change.

• by pclmulqdq on 4/4/24, 3:54 AM

  Beautiful work, and a great choice of processor to emulate. As I understand it, they also tried to get close to the layout of the actual chip, not just make a functional equivalent circuit.

  The next time I have some time, I would love to do a discrete RISC-V, but I know how big a project this sort of thing is.

• by playa1 on 4/4/24, 5:50 AM

  Projects like this are a great way to appreciate how much can fit into an IC.

  Reminds me of the Megaprocessor project.

  https://www.megaprocessor.com/index.html

• by apantel on 4/3/24, 8:42 PM

  This is the Japanese Cloisonné of circuit boards. Beautiful, well-done.

• by johnwbyrd on 4/3/24, 10:52 PM

  Fun project, but fairly old news at this point.

• by grishka on 4/3/24, 8:24 PM

  A macroprocessor.

• by dylan604 on 4/3/24, 9:34 PM

  This would be a great piece of art for a very niche space, like my office =)

  The fact that it actually works is just bonus.

• by namuol on 4/4/24, 3:33 AM

  See also: https://gigatron.io/

  Gigatron is a retro 8-bit computer with no microprocessor. Instead, its processing is done through thoughtful application of “TTL” logic chips. It’s another project that helps you “see” the processor’s internals. Kits aren’t for sale anymore through the official website, but you can find unpopulated PCBs and the components shouldn’t be hard to find.

• by tocs3 on 4/3/24, 9:42 PM

  I would like to see a mechanical version of something like this.

• by KingOfCoders on 4/4/24, 5:10 AM

  I'd love to have a Z80 version.

• by _spduchamp on 4/5/24, 1:09 PM

  I want a MOnSter 6581

• by hyperthesis on 4/3/24, 8:44 PM

  what nm node is this?

  when would it have been state of the art?