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Description
The programme deals with the computer model which forms part of the correspondence material. This model was specifically designed to show the fundamental components of a simple computer, logic, con...trol, input, output units and the store. David Tinsley (OU Consultant) introduces a television version of the model and illustrates how the contents of any location in store can be interpreted, either as data or as an instruction. This leads to the idea of a control cycle. Professor Pengelly (OU) develops a mechanical version of the Fetch - Execute - Reset cycle. They continue by showing how this control cycle drives the computer model through a sequence of instructions - including the problem of conditional and unconditional jumps. To show that the model is realistic, the programme concludes by showing the memory address register and the Instruction Counter of a Hewlett Packard Computer which is being run in simple shot mode.
Metadata describing this Open University video programme
Module code and title: PM951, Computing and computers
Item code: PM951; 05
First transmission date: 09-06-1973
Published: 1973
Rights Statement:
Restrictions on use:
Duration: 00:24:18
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Producer: John Richmond
Contributors: Mike Pengelly; David Tinsley
Publisher: BBC Open University
Keyword(s): Computer model; Control; Control cycle; Fetch-execute-reset cycle; Fundamental components; Input; Instruction counter; Jumps; Logic; Output
Footage description: Mike Pengelly introduces the programme which deals with the computer model forming part of the correspondence material. David Tinsley demonstrates a television version of the model and shows it has five main components. He explains how the contents of any location in store can be interpreted either as data or as an instruction, and shows how the instructions are executed. Using another model, Pengelly develops a mechanical version of the Fetch-Execute-Reset cycle by which the computer operates. Tinsley continues by taking the example of the 'R in the month' PORK program used in TV programme 2, using a video animation to illustrate the broad outline. He comes to the problem of conditional and unconditional 'jumps' or departures from the natural sequence of operation. Pengelly expands his model of the control cycle to cope with this problem. Pengelly and Tinsley together run through a complete sequence of operations required by the PORK program. Tinsley sums up the central role played by the control unit. To show that the model used in the illustration is realistic Pengelly introduces a film insert showing the memory address register and the instruction counter of a Hewlett Packard Computer being run in simple shot mode. He concludes by saying that the basic features developed in the model are to be found in the organisation of any computer.
Master spool number: 6HT/70894
Production number: 00525_4073
Videofinder number: 660
Available to public: no