Making a Little Smalltalk

Making a Little Smalltalk

While things like object oriented computing and model-view-controller are old hat these days, when Smalltalk burst on the scene, many people had never heard of these new ideas. While the little language with roots at Xerox and based on Simula never caught fire, it was very influential in a number of ways. Now Smalltalk luminary [Dan Ingalls] has the Smalltalk Zoo, a collection of Smalltalk-related items including several historical simulations you can run in your browser.


We were especially impressed with the AltoSmalltalk-72 simulation since our chances of running a real Alto are pretty slim. The JavaScript behind it actually implements the Alto’s Nova instruction set. The emulator then runs a 45-year old memory dump from a real Alto. According to [Dan], there’s no file system and the microcoded music and animation instructions are missing, but he hopes someone will add them as a spare-time project.

There are a few other project suggestions for anyone brave enough to dig into this old software. We found it amusing that the Smalltalk-72 Javascript interpreter runs over 500 times the speed of the original and has “nearly unlimited” object storage.


In Smalltalk everything is an object. With things like the turtle graphics object (@) and you can say things like:


@ go 50 turn 90 go 50 turn 90 go 50 turn 90 go 50

It is less amusing when someone tells you they sent the + message to the 3 object in order to add something to 3, but that’s object-orientation for you. If you don’t know Smalltalk, try the snippets you can find on the right side of the emulator.



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