Leap Technology

aamoviebb2 HN recommenders · 2014–2026
25K views · demo · evergreen · Uploaded 2011-04-23

A promotional video for Leap, the navigation technology invented by Jef Raskin, demonstrated on the Canon Cat computer around 1987. It shows keyboard-driven search and cursor positioning in place of a mouse.

HN uses it as the visual reference for Leap keys and Raskin's interface ideas whenever jump-to-text navigation or command palettes come up.

Watch on YouTube

12 comments from Hacker News

@smorrow2014 · in “Jef Raskin's Swyft Card”

I don't know anything about the Swyft card, but I know something about the Cat (not much). The Swyft card implemented at least the cursor positioning stuff in this video: [VIDEO] Some things about the Cat that aren't in that video are interesting. The whole thing was a single-user (fine by me), single-process (fine for the time) and single-program system. When you turn it off it writes its whole memory (incl. framebuffer) out to disk, which I think is the only thing on the disk actually, and when you turn it on it reads it back in to memory. So it never had any concept of a file, of saving a file, or opening a file. Saving a document was just saving your state, which includes the document, and opening a document was leaping to that part of the screen. You could migrate your session by just carrying the disk with you. The tabulating and (re)calculating thing is slick, and I think the Swyft might have provided that feature too. If someone could figure out a way to reconcile that with the Unix notion that different programs, running in different processes, must do different things, I would be so happy.

@fzzzy2016 · in “Restoring YC's Xerox Alto: how our boot disk was trashed with random data”

I had read a lot about the Cat, but never saw it in action, so I decided to look for a video. This is a fascinating view into Raskin's user interface concepts. The world might have been a very different place if Jobs hadn't interfered with the Macintosh project. [VIDEO]

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@marttt2020 · in “Leap Technology (keyboard vs. mouse on a Canon Cat machine, ca 1987)”

More on the Canon Cat: [LINK] [LINK] There are also a few previous HN discussions on this machine. EDIT: I just have to post this lovely scene from the original video separately. This is about human-computer interaction after all, isn't it! [VIDEO] Aren't we actually approaching an age where this kind of (almost-)single-purpose machines might be making a comeback? The focus this model seems to allow or enforce on the user feels kind of... healthy.

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@lproven2021 · in “Canon Cat”

I have never played with one, only studied the videos (e.g. [VIDEO] ) and documentation. It was a very radical UI. If you added programs, they just added new functionality to the existing editor. So, for instance, a spreadsheet module might mean that suddenly, when loaded, you can do operations like SUM{...} or MEAN{...} on a table of numbers in the editor. I've long wished that someone would implement the Canon Cat UI as an Emacs module. It would seem to me that Emacs has all or most of the necessary functionality already.

@jodrellblank2021 · in “Command palettes: how typing commands became the norm again”

I could have sworn I saw a dropdown command/search dialog designed by Jeff Raskin as part of The Humane Interface, and demonstrated in PyTHE a Python imeplementation of it. Can't find any evidence of it, but I can find a 2003 Guido van Rossum review of Jeff Raskin's book "The Humane Interface" in which Raskin mentions LEAP(r) a design for adding search-backwards and search-forwards keys below the spacebar to save people from arrow keys and mouse use, which is demonstrated on the CanonCat computer from 1987 in this[2] video on YouTube. [1] [LINK] [2] [VIDEO]

@retrocryptid2022 · in “The Canon Cat”

If you press and release the LEAP key, it advances the cursor one character forward (or backwards if you hit the left leap key.) If you press down (but do not release) the LEAP key you enter a search semi-mode. As you type a search term in this semi-mode, the cursor moves to the first instance of that search term it finds. After moving to the first instance of the search term, you release the leap key to exit the search semi-mode. If you want to move the cursor to a subsequent instance of the search term, you press (and do not release) the "USE FRONT" key and press the leap key again (whose key front is labeled "Leap Again.") You can see this in action in this YouTube video, but it happens pretty fast so you have to watch carefully: [VIDEO]

@afry12023 · in “Vim-like “jump” cursor for Mac OS Window Management”

For my emacs friends, here's a wonderful package that provides the same functionality: [LINK] And, if you're interested in some historical context for this "type characters and jump to point" functionality, the Canon Cat: [VIDEO]

@throwaway712712023 · in “PicoCalc: A Fully-Functional Clone of VisiCalc”

That looks seriously cool. Just the colors give me goosebumps :) completely offtopic: My dream is to build a super cheap child friendly computer, that the kids can build themselves, has a software keyboard that directly polls the gpio pins so that kids can modify their keyboard instead of having a keyboard controller (just so there is less mistery in what happens when a key is pressed). And the OS is something inspired from LEAP: [VIDEO] that allowing you to evaluate code and apply it to your current file. A bit like your LOAD81 but with text. I have a prototype now: [LINK] but it has a long way to go.

@tivert2023 · in “Version Museum: A Visual History of Your Favorite Technology”

This is kind of neat from a nostalgia standpoint, but I wish there was some kind of "Encyclopedia of Operating System UI," that broke UI features and paradigms down into their smallest units and tracked them across different operating systems and versions. Probably with a particular emphasis on defunct systems when there was a lot more diversity and innovation (e.g. the Canon Cat Leap Keys: [VIDEO] )

@kalleboo2024 · in “Preliminary Macintosh Business Plan (12 July 1981) [pdf]”

> I can't find any demo or screen shots of the Canon Cat system in use There's an advertising video on YouTube showing it in use for text editing [VIDEO]

@entaloneralie2026 · in “Writing my own text editor, and daily-driving it”

One of the first thing I added was Leap keys-type search, I didn't want modes. - Leap keys: [VIDEO] The second was pragma-mark navigation, so I can always see a overview of the codebase. - navbar: [LINK] I also wanted a local copy buffer specific to the project I work on, so I could easily manage multiple copies of the clipboard data(it's part of how I work).

@OhMeadhbh2026 · in “Macs Since 1983”

Meh. the Lisa was absolutely, positively, explicitly NOT a Mac. If you don't get that, then you misunderstand the business of computing in the late 70s / early 80s. The author also ignored Jef Raskin's work on the original Mac project (I wrote a serial driver for him in the early 80s for a 6809 prototype he was working on.) If you're going to make one of these Mac hagiographies, it's useful to point out the Canon Cat (which was more in line with Jef's original idea for the Mac) and then point out how different it was from main-stream Macs. And then point out WHY the Lisa was not a Mac. So... Why do people think the Lisa was a prototype Mac? It's easy to understand the confusion. It has a 68k processor, a mouse and a bitmap screen. It was even used as a development platform for the original Macs. But it is not a Mac. The Lisa didn't have "apps" and "files" in the same way we think about them. It had "tools" and "documents." The Lisa was strongly influenced by the Xerox Star. And while it's not exactly true to say the Lisa was Apple's version of the Star, there was definitely a strong resemblance. The Lisa (and the Star) came with all the functionality it would ever have built into the system. (This restriction changed later, but when launched, it was considered a complete system.) It had "apps" in the sense there were tool icons you could (double?) click to create a blank document of a specific type. But it took Apple over a year to decide they wanted to give third-parties the