Couch to 64k, a.k.a. Building a Z80 Breadboard Computer (2020) | Hacker News Reader

Couch to 64k, a.k.a. Building a Z80 Breadboard Computer (2020)

bread80.com

122 pointsAlexeyBrin16 comments

If you don’t want to deal with breadboards, there are lots of cheap (under $50) programmable Z80 computers out there; here are a few I’ve collected:

* Timex-Sinclair 1000 (American ZX81 with double the RAM — an entire 2KiB!)

* TI 81-86 graphing calculators

* Verifone Tranz 330 https://www.bigmessowires.com/mozart-tranz-330/

* Cidco MailStation https://jcs.org/2019/05/03/mailstation

Also, for a bit more money, there are lots of new hobbyist computers out there, including the RC2014, Stephen C. Cousins’ “SC___” series, and the MinZ / eZ-Tiny series. You can solder them together and program however you like, oftentimes including booting CP/M off of ROM, MicroSD, Compact Flash, or floppy.

For anyone not familiar with it: the title is (presumably) a reference to the NHS "Couch to 5K" program[1] and app[2].

[1]: https://www.nhs.uk/live-well/exercise/running-and-aerobic-ex... [2]: https://apps.apple.com/gb/app/nhs-couch-to-5k/id1082307672

nitpick: the original C25K has nothing to do with the NHS, it was made and popularised by the folks at coolrunning.com

For anyone wanting to get fit, highly recommend this program. I went from not being fit to running a half marathon in about six months

I was wondering about that, I didn't see anything about the couch in the text but I was thinking about it.

One of the essential first steps in many a worthwhile project is to focus the necessary determination, whatever it takes, on initially getting up off the couch.

Myself, I went without a couch for years.

Would highly recommend.

Nice. After decades of high level software development, I’m starting to get back in to microcontroller/processor and “bare metal” development. I first learned to code with Basic and Assembly on the Z80 inside the early Sinclair products. I’m having fun now with the ARM cores in the various cheap Raspberry products (the Pi 4b and Pico so far).

I did come across the Ben Eater series which looks awesome too. (https://eater.net/). I’m excited to try and build a video card from scratch!

There’s so many options today it’s almost overwhelming. I’ve been trying to think how to best introduce my youngest without bewildering him. Anyone had success on a “low level” path with young kids that kept them entertained?

This is the first part of a series: http://bread80.com/category/couch-to-64k/

This is super cool. When I was in college I used a breadboarded Z80 with an FPGA to build a really simple video game system with VGA output and a Genesis controller for input. The schematics, source code, and project write up are still on my home page (http://trzy.org — near the bottom). I should probably throw it up on GitHub.

Love these kinds of writeups! I've been learning 6502 for NES programming because I too have the nostalgia factor for these old machines.

See this if you want to try something similar with a 6800 MCU:

http://zoom.interoscitor.com/PetersonEnterprises/Consulting/...

Requires writing code directly in hand assembled MCU instructions. The bootstrap code (3 instructions) is written in diodes!

I feel like the arduino is cheating

All it's doing is generating a clock. How's that cheating?

It’s only used to generate a very low clock rate. It’s replaced with a 4MHz oscillator later in the series.

Using the Arduino is a great idea. It can provide scaffolding during the development process, and can replaced with something better suited to the task when they are ready.

The test harness! When one lacks more sophisticated gear, this is a great way to get started and have a chance at success.

BTW: I love Propeller chips for this purpose!

They are multiprocessors in both the parallel and concurrent sense and that makes them quite useful! One can build up simple scopes, logic analyzers, signal generators, and other useful tools and use the chip to both display output, measure and more.

I know what you mean but I actually thought it was quite a cool way to start out and as someone else has said, it is replaced later.

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