This control desk for the TOSBAC computer was part of the interface between the operators and the computer system that was used to monitor and control the high voltage power distribution for NSW, Australia. Transgrid, the organisation that donated these cabinets, oversees and coordinates high-voltage electricity transmission in New South Wales. They are one of the companies that were formed to take over the duties of the former State Electricity Commission.

The TOSBAC Series 7/70E System, of which this control desk forms a part, is a Supervisory Control and Data Acquisition (SCADA) system designed and marketed by Toshiba. It runs TREX 2 (Toshiba Real-time EXecution) which is a special operating system for SCADA. While the TOSBAC and TREX comprise a computer system designed for general control application, this system was especially commissioned to run the State grid in NSW. It was purchased in 1982 and was running by 1985. DAC, (Data Acquisition and Control) as it is known by the Transgrid engineers who operate the system, is the third computer system to have been used to control the grid. The first was an analogue computer from Leeds and Northrop called George which was installed in the mid 1960s, and the second was a PDP/11 called Little George which ran from 1978 to 1985/6 when DAC was brought on line.

The TOSBAC system illustrates the use of computers to implement sophisticated control of a major public utility, and the importance of computer systems to our technological infrastructure. It was still in use up until 2003 and had been controlling NSW's high-tension transmission for the better part of twenty years. Prior to the grid being set up, power stations had to be built at the site of the power requirement. For example the Powerhouse Museum currently resides in the former power station built to supply electricity to Sydney's tram system.

The understanding of power transmission has had implications for computing history. American scientist and engineer Vannevar Bush built his famous differential analysers in order to perform the calculations necessary to understanding the behaviour of transient signals in electricity transmission lines.

Moreover, this computer system represents an essential aspect of industrial and technological practice: control. From the governors used with industrial steam engines in the 1800s through to the operating system on personal computers, all technology requires a control system. Electricity is one of the most valuable and volatile elements of modern life. A highly sophisticated and reliable method of control is required to enable the safe delivery of electricity. The TOSBAC system is a significant example of a control system designed to manage an often unpredictable but essential commodity.

Damian McDonald
October 2007

The keyboard, control panel and communication console were manufactured by the Toshiba Corporation in Japan, 1983. The wooden desk and cabinets was manufactured in Japan for Toshiba.

Toshiba was formed in 1939 with the merger of two companies: Shibaura Engineering Works and Tokyo Electric. The merged company - Tokyo Shibaura Denki - was nicknamed Toshiba, and in 1984 the company was officially renamed the Toshiba Corporation.

The Communication Console was originally used in Transgrid's Yass control room. This console would have been permanently attached to the control desk. In practice there were two methods for positioning the console. Earlier installations had the console just bolted to the rear of the desk but it was found that insufficient space remained on the work surface for A4 sized documents, so an extension was fitted to the rear of the desk top to extend the desk surface by about 90mm, which was then sufficient for a useful work area. The communication console was retired when the diverse brand of exchanges were replaced by a corporate integrated Ericsson PABX system.

Control desk for TOSBAC (Toshiba Scientific and Business Computer) computer system, with keyboard and control panel, communication console with handsets (2) and cabinets for monitors (2), wood / plastic / metal / electronic components, made by Toshiba Corporation, Tokyo, Japan, 1983, used by Transgrid NSW, Australia, 1985-2003

This control desk consists of a purpose constructed wooden desk with rebates for a keyboard and control panel. The desk has a return for placing monitors, printers and other peripherals. Under the left side of the desk is a set of three drawers for stationery and files.

The keyboard situated to the rear of the desk consists of a standard alpha-numeric keyboard with added dedicated function keys to control the CPU. The control panel situated at the front of the desk has on its right side a set of keys that duplicate the function keys on the standard keyboard; and on the left side a set of buttons that display alarms and also duplicate function on the CPU.

Also included is a Communication Console with two handsets and function keys relating to remote sites - specifically Yass and Wagga in regional NSW, Australia. The console is divided into four sections. The one column of buttons on the LHS were available for control room functions like alarm bell extension and backup alarm system bell acknowledge. The next group of three columns of buttons are provided for an old 'operational switching unit' (OSU) phone system which was a backup phone network which had manual trunk selection. The next six columns were connected to direct line connections to each of the substations under the control of the operator as well as other control rooms. The right hand group of buttons accessed the VHF radio network. The handset for the radio has a push-to-talk switch.

The two cabinets for monitors are made of the same wood as the desk. They are mounted on four castors for easy movement, and have a door on the front. There are four holes drilled through to the inner cavity of the cabinets (one on each corner) to enable cabling to be recessed. There is power and computer cabling mounted inside both cabinets. The monitors sit on the top of the units.

Made: Toshiba Corporation; ; 1983

Keyboard: Model PRBL8315A002; Serial Number PD 7010; The Electricity Commission of NSW No CA/0748

Under top drawer of desk: MP -2G

Communication Console: 'Paging Yass - 716/Wagga - 911 410'

2008/58/2

1983

820 mm

1500 mm