Skip to main content

Emulating Smalltalk-76

If you got as excited as me about Dan Ingalls' live Smalltalk-76 demo on an actual 1970's Xerox Alto, you may have wanted to try it yourself. 

For one, you could try my Smalltalk-78 VM. Smalltalk-78 is a leaner version of Smalltalk-76 but very much identical in syntax semantics. 

It is also possible to run the full Smalltalk-76 environment, and here is how:

First, you need an emulator for the Alto computer. Ken Shiriff posted a nice piece on how to run ContrAlto on Windows. It is written in C# and I got it to work on my Mac using Mono. So here's a step-by-step:

  1. Install Mono from http://www.mono-project.com/download/
  2. Download ContrAlto-mono.zip from https://github.com/livingcomputermuseum/ContrAlto/releases
  3. Download this Smalltalk-76 disk image: http://www.bitsavers.org/bits/Xerox/Alto/disk_images/chm/xmsmall.zip
  4. Unzip both ContrAlto-mono.zip and xmsmall.zip in the same folder.
  5. In a terminal, change to the ContrAlto directory and run mono Contralto.exe. This opens the Alto screen in a new window, and the emulator control in the terminal. 
  6. (if you get an error about a missing SDL library at this point, install that via homebrew using brew install sdl2)
  7. At the emulator's ">" prompt, type load disk 0 xmsmall.dsk and then start:
    $ mono Contralto.exe
    ContrAlto v1.2.2.0 (c) 2015-2017 Living Computers: Museum+Labs.
    Bug reports to joshd@livingcomputers.org

    You are at the ContrAlto console.  Type 'show commands' to see
    a list of possible commands, and hit Tab to see possible command completions.
    >load disk 0 xmsmall.dsk
    Drive 0 loaded.
    >start                  
    Alto started.

    >
  8. In the Alto screen window, type resume xmsmall.boot to start up Smalltalk-76:
      
  9. And now you should see Smalltalk-76 running!
  10. There is no explicit "save" option. The OOZE object swapping system continuously writes objects to the disk. Use "quit" from the main menu to flush all objects back to disk.
Note that you will need a 3 button mouse to properly interact with the system. On my MacBook, I installed MagicPrefs to emulate a third mouse button. After installing, in MagicPref's "MacBook Trackpad" section, for "Three Finger Click" choose "Middle Click".

You will also need some keyboard shortcuts to access the special characters in Smalltalk-76:
ctrl A             ≤ (less or equal)
ctrl B             bold
ctrl C             user interrupt
ctrl F             ≡ (identical)
ctrl G             ◦ (index operator)
ctrl I             italic
ctrl N             ≠ (not equal)
ctrl O             ↪ (quote)
ctrl Q             ⇑ (return)
ctrl R             ≥ (greater or equal)
ctrl S             's (eval operator)
ctrl T             ┗  (prompt)
ctrl U             ¬ (unary minus)
ctrl X             clear emphasis
ctrl /             ⇒ (if then)
ctrl =             ≡ (identical)
ctrl shift =       ≠ (not equal)
ctrl \             ≠ (not equal)
ctrl ]             ⌾ (create point)
ctrl [             ◦ (index operator)
ctrl :             ⦂ (open colon)
ctrl '             ↪ (literal quote)
ctrl <             ≤ (less or equal)
ctrl >             ≥ (greater or equal)
shift -            ¬ (unary minus)
cursor down        doit (in dialog view)
To learn Smalltalk-76, the User Manual is a good starting point:
http://xeroxalto.computerhistory.org/Filene/Smalltalk-76/.document.press!1.pdf

Have fun!
Labels:

Comments

Zimbabwe vgtjbkjkij said…
This is awesome. Thank you!
November 17, 2017
Post a Comment

Popular posts from this blog

Frontend-only Multi-Player. Unlimited Bandwidth. Or: What is Croquet.io, really?

A multi-player web app needs a backend, right? What if I told you, it doesn’t? Read on for how Croquet gets rid of servers running your multiplayer code. No, really . Instantaneous Shared Experiences  is how we describe Croquet on our website. And while that excellently describes What Croquet does, as Croquet's Chief Architect, I wanted to share a bit about How we do that. So I wrote a Twitter thread . Here it is in blog form, slightly extended. Click the animation above if it does not play automatically Croquet lets you build completely client-side multi-user web apps. Read that again. Client-side. Multi-user. No I’m not kidding. I built it, I know it works. 😁  Croquet apps run completely client-side: are hosted as a static web site no server-side code needed no networking code needed  Croquet is literally virtualizing the server: Instead of running code on a server (or in a serverless function) we run it as a virtual machine (VM) on each client.  Croquet carefully control
1 comment
Read more

Deconstructing Floats: frexp() and ldexp() in JavaScript

While working on my  SqueakJS VM, it became necessary to deconstruct floating point numbers into their mantissa and exponent parts, and assembling them again. Peeking into the C sources of the regular VM, I saw they use the  frexp ()   and ldexp () functions found in the standard C math library. Unfortunately, JavaScript does not provide these two functions. But surely there must have been someone who needed these before me, right? Sure enough, a Google search came up with a few implementations. However, an hour later I was convinced none of them actually are fully equivalent to the C functions. They were imprecise, that is, deconstructing a float using frexp() and reconstructing it with ldexp() did not result in the original value. But that is the basic use case: for all float values, if [ mantissa , exponent ] = frexp (value) then value = ldexp ( mantissa , exponent ) even if the value is subnormal . None of the implementations (even the complex ones) really worked. I
6 comments
Read more

Smalltalk Bindings for Minecraft Pi

The Raspberry Pi is a cute little computer. Quite cheap at $35, you plug in USB keyboard+mouse and a TV as monitor. And it is surprisingly capable, even for running 3D games. One particularly interesting game is Minecraft: Pi Edition . As in other Minecraft versions, the main goal is to create a world. But unlike other versions, you can not only use the tools provided by the game, you can make your own tools! That's because it comes with a programming interface. The Minecaft world is made of little cubes, and you normally place or remove these blocks by hand, one after another. This is fun, but for larger structures also quite cumbersome. For example, this rainbow here might take a long time to construct manually: But I did not make the rainbow by hand. I programmed it, using the Smalltalk programming language. It's just these dozen lines of code in the Squeak programming environment: Squeak is already installed on the Raspberry Pi, because Scratch was made in Squeak
4 comments
Read more