Squeak: A PD Smalltalk system

Squeak is a free Smalltalk system released by a team (originally at Apple, now at Disney) lead by Alan Kay and Dan Ingalls and Ted Kaehler. Yes, them, you know the names, the ones that did the original version all those years ago at PARC. Along with some other talented people both employed in their team and outside, they have produced a rather nice Smalltalk system with the unusual virtue that both the image and the VM are Public Domain - ie free, gratis and no charge to you sir. Better yet, the VM C-code can be generated from the Smalltalk simulation of the VM.

To find most of the web resources for Squeak, look at the Squeak.org site or Stephen Pope's site Squeak Smalltalk Mailing List & Resources There are lots of pointers to information about Smalltalk, tutorials, FAQs etc. I won't waste space by duplicating any of it here.

Here are three gifs of the Squeak logo that you may like to use:-

• 32x32
• 48x48
• 64x64

Squeak runs on Macs, most unix systems, Windoze NT & 95 and Acorn RiscPC. I'm responsible for the Acorn RiscOS port. (It probably runs on any post ROS3.1 machine but I only have a couple of RPC-StrongARM machines to test on. How we suffer for our art.) See the above mentioned master page for details on how to get the files for any port other than the Acorn one.

Acorn Squeak 1.23(b) is here!

To build Acorn Squeak from the standard release 1.23 files you need to run the standard distribution system on a Mac (or the other versions on the appropriate machine) and filein the changes files in the SqFiles/deltas directory and grab the C files, makefile etc. and then build the release. Or you can be lazy/sensible and fetch a complete built system by grabbing this Sparkived ZIP and extracting the files. For those of you that have trouble downloading big files, there is also a set of 4 smaller zip files , one with each of the major runtime components.

1. sq123-bp1, the Squeak interpreter application
2. sq123-bp2, the Squeak changes log
3. sq123-bp3, the Squeak virtual image file
4. sq123-bp4, the Squeak smalltalk sources file. If you have a copy of an earlier Squeak release, you do not need to get a new copy of this file

One of the major changes needed for the Acorn was to make BitBlt capable of handling little-endian memory. Read this to see what was done and to get the changes.

This 1.23b release has my SystemCall classes added. This allows you to make SWI calls and thereby access all the RiscOS swis. By way of examples, look at AcornSystemCall class getEnvironmentVariable: & setEnvironmentVariable:to:. Using SWIs can be very dangerous, since some of them are quite capable of trampling all over memory. Use themwith care and let me know about problems you find

Known bugs and omissions

There are several things known to be wrong, and probably lots not known.

• The system currently has no sound output or input set up. This is because I know nothing at all about RiscOS sound things. All help gratefully received.
• There are some interesting quirks in the display system if you try to use a Squeak Display of 16 or more bits per pixel. This is due to the RPC having a different idea of the ordering of RGB within the memory to the Mac. I have no idea if it is possible to fix this yet! Basically you get reds instead of blues, though greens stay the same. Looks quite odd. If you know how to use a pixel translation table with 16/32 bpp modes, let me know.
• There are lots of places where the filesystem has problems. Two main problems cause this
  1. lots of Squeak code assumes that a dot is a reasonable character in a filename or that a colon is a good directory separator (Mac lineage again). I've tried to catch at least the important ones involved in image saving and filing out code.
  2. it is assumed that you can open a file multiple times to read, which RiscOS does not do. If you run the system from inside X-Files, or (so I'm told) a tar format !SparkFS, this is not so much of a problem. It seems to be a restriction of the CLibrary rather than RiscOS.
• no keyboard shortcuts for menu options, since I can't find a way to test for the ALT key being pressed. Miles Sabin is trying top help me with this.
• no useful icon-bar capabilities yet. I'll put a menu on it someday.
• no serial port or sound output

email me at tim@sumeru.stanford.edu