The Centre for Computing History gets a BCL Susie

BCL Susie

Last week, The Centre for Computing History added a BCL Susie to the museums collection

BCL Susie (Stock Updating Sales Invoicing Electronically) used a magnetic drum store and the Molecular18 computer system which was was an 18 bit, dual accumulator, programmable computer, with a typical minicomputer architecture. The Molecular could address up to 64K words of memory. In later models, memory extensions were made available by the use of bank switching.

The top 32K memory could be switched between four banks, giving an overall memory limit of 160K words. There was a complex (for the time) instruction set, a simple interrupt system, multiple input/output ports, and Direct Memory Access or Data Channel for high speed peripherals.Susie was primarrily a stock control machine in 1967 which used a Nickel Delay line and Magnetic Drum for storage.

The only system controls are the keys of the typewriter keyboards on the input/output writers, apart from a few switches for program selection and automatic input and output. Therefore, any reasonably intelligent typists could soon learn to operate the equipment.

The system had automatic Input and Output using either punched paper tape or edge-punched cards, a great deal of information which would otherwise have to be inserted by the typist, can be fed in automatically at far greater speed and with absolute accuracy, Susie can generate statistical information for further processing on a customers own computer or by a computer bureau as part of another operation, or for future use as standard input material. Susie can accept such items as customers’ names and addresses, account numbers and so on, on one card, and standard item descriptions and prices on another. Fed into Susie either individually or automatically by hopper, these cards make it unnecessary for the operator to type anything other than the variable information. Automatic input can increase Susie’s memory capacity to virtually limitless proportions by replenishing it in sections from stored punched tape or cards.

Independent Operation of Readers and Punches and Input/Output Printers. These two units are completely independent of each other. The ability to use them together or independently facilitates the rejection of wrong edge-punched cards or tape sequences without producing hard copy. Susie has the ability to re-generate punched paper tape without producing hard copy printout. This enables the typist to ‘dump’ data from the memory, completely by-passing the print unit. The input of fresh data or of a programme can be carried out at the same speed. Susie programmes are fed in on paper tape or typed in via the keyboard.

A hopper fed edge-punched card reader is available, capable of processing automatically up to 200 edge-punched cards without the typist’s intervention or handling.

The system is complete with a high speed GNT Model 34 Tape/Punch reader. It punches standard 1″ paper tape with 8 information channels according to one of the three standard codes namely ASCII. Fridens Flexowriter, or IBM TTC/8.

Our BCL Susie Mark 2 machine was very kindly donated and built up for us by Tony Fairhead who knew and used the machine for many years.

By Andy

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