The Sydney University SILLIAC

Last updated: 14 August 2010: David Green


Photo courtesy of the Science Foundation for Physics, University of Sydney

SILLIAC was the first computer to be installed in Sydney University, in Australia. It was a vacuum tube {electronic valve} machine that used electrostatic storage tubes for memory.

The SILLIAC, shown above being operated by Ms. Pat Dunlop, entered regular use in July 1956.

Later, in 1958, the SILLIAC instuction set was extended to include various new instructions and at about the end of 1959 four magnetic tapes were installed.

SILLIAC was switched off for the last time on 17 May 1968. It was scrapped and little of it, hardware or software, survives today.

This Web site is intended to be a resource for anyone interested in this early computer. The resources will include (as work progresses)

 SILLIAC Programming Manual - cover

The SILLIAC Programming Manual

My copy of the SILLIAC Programming Manual contains a full description of the program codes as they were in 1958. I have scanned the manual and it is available here. As the total size of 44 Mb is a mega download if you don't have broadband, I have split it into three smaller, more easily managed .pdf files, comprising Chapters 1 - 5 (13.5 Mb), Chapters 6 - 12 (13.2 Mb), and the remaining chapters and appendices (17.0 Mb).

The manual and the picture of SILLIAC are reproduced here with the kind permission of the copyright owners, the Science Foundation for Physics at the University of Sydney. index top

A SILLIAC Emulator

I have written an emulation of the SILLIAC. Version 1 of the emulator is written in C and operates under DOS. You can download it here. Version 2 is written for Windows (and needs 32 bit operating system, and 800x640 minimum screen size). The emulators have not been tested as exhaustively as I would like but they handle the listed examples.

The emulators implement both the 1956 and the 1958 instruction sets.

Hardly any descendants of the IAS computer were exactly alike but some other copies of ILLIAC were very similiar to SILLIAC. For example, a program for MISTIC (the Michigan State Intregral Computer) and once listed on the Michigan State University web site, runs without alteration on the emulator. index top

SILLIAC/ILLIAC Program Library

We are fortunate that Wayne Lichtenberger had the foresight to preserve several volumes of documentation of the ILLIAC program library. They have been scanned by Al Kossow and placed on his web site. They are: the Active Library, the Auxiliary Library, and the Statistical Library.

Wayne also preserved a paper tape copy of the protected section of the ILLIAC drum, and a listing of this have also been posted by Al Kossow.

We are equally fortunate that the late George Brooks (who was SILLIAC's last engineer) kept a variety of notes and listings of the SILLIAC maintenance programs, and that these have found a safe haven in the archives of the Sydney Powerhouse Museum. The following copies are reproduced here by kind permission of the University of Sydney Science Foundation for Physics, and with thanks to the Powerhouse Museum for preserving the material and to John Deane for making the copies.

As a result, a substantial amount of code is now available for the emulator. Not all the routines and programs are of equal interest (to me, anyway) but the ones I have reconstituted and tested are provided below (or will be, in the fullness of time - work-in-progress!) index top