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The Canon Cat

October 13, 2025

Here’s another Wikipedia rabbit hole post. This time about the Canon Cat: a weird little computer from the late 1980s.

As I’ve mentioned before, I often read Wikipedia when trying to get back to sleep. This time I was looking into the Data General Nova series of minicomputers. I had watched a fun series on the Tech Tangents YouTube channel about the restoration of a microNOVA, and I was curious what Wikipedia would have to say about it. I was almost immediately sidetracked by this image near the top of the article.

To the right of the pictured Nova System were three microcomputers. I recognised the one at the bottom as an Atari 400, and the one in the middle as a Radio Shack TRS-80, but I wasn’t familiar with the one at the top. Zooming in, I saw it listed as a “Canon Cat” on the placard. Though it wasn’t familiar to me, it looked like the Platonic ideal of an 80’s computer.

The Wikipedia page for the Canon Cat is quite short, but it was dense with interesting bits. It was created by Jef Raskin? The Macintosh guy? And it didn’t have a mouse? It was based on FORTH? What are those weird keys below the space bar?

This morning I did a bit more digging and I’m quite surprised that I hadn’t come across this thing earlier. It’s fascinating! The Register posted an article about the Cat last year that links to a promo video on YouTube showing off the “Leap” buttons (those two red buttons below the space bar). It also demoed some interesting features of the OS, which was sort of an all-in-one office suite that the machine booted into. The article also includes a video showing how to enter the FORTH console, along with links to documents on canoncat.net. I also found a Canon Cat page on Vintagecomputer.ca with some excellent photos of the machine.

Most interesting to me was a link to an emulated version of the Cat on Archive.org. This page also links to a reference manual and workshop manual/repair guide. Playing around in the emulator, I found the left and right Option keys on macOS could be used as Leap keys, and Control can be used as the “Use Front” key. There’s a procedure on page 3 of this tForth Manual for entering FORTH mode. However, I wasn’t able to get this to work in the emulator. 1 Please let me know if I’m doing something wrong here.

Anyway, this was a fun diversion on a lazy Thanksgiving long weekend. If you have any stories or other resources about the Canon Cat, please feel free to reach out on Mastodon or Bluesky.

  1. I did this by typing Enable Forth Language by itself on a line, hitting both Leap keys (left and right Option) to select that text, holding down “Use Front” (Control) and pressing Erase (Backspace or “Delete”), then holding “Use Front” + Shift + Space. This seems to freeze the emulator, though. I also found this emulator worked much better in Chrome than in Safari. ↩