Retrocomputing on mjgraf.net

Bringing an old computer back to life

Sat, 31 Jan 2026 00:00:00 +0000

Slowly returning to the retrocomputing hobby after 12 14 many years, most of my collection has been in storage way longer than I anticipated in 2006.¹

That means I’ll have to treat every machine I take out of storage essentially as an unknown. That’s why I looked around on the internet for some best-practice checklist on how to proceed with “new” old computer, but couldn’t find anything.²

So here’s my attempt. I’ll extend and modify it as I take more and more machines out of storage. I welcome your feedback.

A Pseudo-Random List of Retrocomputing Reverse Engineering Links

Fri, 23 Jan 2026 00:00:00 +0000

Another list I’m putting together for my own benefit (the first one is here).

Reverse Engineering Frameworks

Ghidra

Ghidra is a free, open-source software reverse engineering (SRE) suite developed by the U.S. National Security Agency. It’s primarily used to analyze compiled binaries, allowing users to disassemble, decompile, and inspect low-level code. One of its standout features is a powerful decompiler that attempts to reconstruct readable high-level code from machine instructions. Ghidra supports many processor architectures and file formats, making it useful for malware analysis, vulnerability research, and firmware inspection. It also includes scripting and collaboration features.

Classic Computer Collector's Code of Conduct

Sun, 05 Jan 2020 00:00:00 +0000

I have no idea where this originally came from, but it’s been around for some 20 years (at least), and I rather like it. Copied from Gaby’s CP/M site.

As a serious collector, I follow the Classic Computer Collector’s Code of Conduct (CCCCC). The CCCCC is listed here for your reference:

I will do my best to find a home for any classic or unwanted computer.
I will return or destroy any personal or commercially sensitive data I find on a machine I acquire, and will keep it in the strictest confidence, should I find it necessary to view it.
I will aid users in the decomissioning of their machines, should they require assistance.
I will respect active software and publication copyrights.
I will, whenever possible, repair the computers in my collection and maintain them in working order, and will assist others in doing the same, to the best of my ability. I will actively encourage the repair, maintenance, and use of older computers, in preference to the irreversable alteration of machines and parts for non-computer applications.
I will actively promote the exchange of computers, parts, and information among collectors, and will refrain from hoarding multiple examples of any item.
I will actively promote ethical collecting.

Inside the Kosmos CP1

Mon, 18 Jun 2018 00:00:00 +0000

Originally, I planned to save all the CP1 stuff for a later post, but there’s this one picture I really want to share. After removing the cardboard back cover,

this is what I saw:

The screwdriver must have been in there for some 15 years at least.

A Pseudo-Random List of Retrocomputing Links

Mon, 01 Jan 0001 00:00:00 +0000

I’ve put this list together as much for my own benefit as for that of potential readers. The only selection criterion was “stuff that I find intersting and want to be able to go back to later.”

Yes, I know browser bookmarks exist.

Blogs & Podcasts

Ken Shirriff’s blog: Xerox Alto restoration, IC reverse engineering – http://www.righto.com

Programming Languages

The Retrocomputing Museum – Languages From Hell — Co-curated and hosted by ESR. Don’t veer into the political parts of his site, it might spoil the fun… ;-)

General / Platform independent

old-computers.com
8bit-homecomputermuseum.at
8-Bit-Nirvana
CPU Shack
AntiqueTech also has a directory of old CPUs
Bitsavers
Datormuseum
Bytecollector – while no longer actively collecting, Bryan covers the very early years of the microcomputer revolution on his site.
The Museum of Obsolete Media
Erik S. Klein’s The Vintage Computer
oldcomputers.net (nice timeline!)
The Internet Archive is more than just the Wayback Machine: Amongst many other things, they also have books and magazines about and software for old computers and consoles, and lots of it. However, unlessyou know what you are looking for, the archive is a bit hard to navigate.

Homebrew

Lee Hart’s Altoid-tin-sized single board computers, the COSMAC ELF Membership Card and the Z80 Membership Card. Lee is also working on putting an Altarir 8800 into an Altoids tin, using only components available at the time.
Grant Searle has built replicas of the Sinclair ZX80, the Jupiter ACE, and the CompuKit MicroUK101, as well as a 6809 and a CP/M machine of his own design.
As his website was unavailable recently, here’s an archived copy at the internet archive.

Counterfeit ICs

A major source for obsolete ICs to use in retro-homebrew projects are Chinese sellers on eBay. Unfortunately, many of them don’t seem to care whether the ICs they sell are genuine or counterfeit. Here are a couple of pages about spotting counterfeit ICs