Systems Development

The General trend is for ever higher speeds and larger storage systems; these in turn demand greater speeds in the input and output systems attached to the computer. At the moment there seems no particular requirement for higher speed, but a possible application will be to make use of the higher speed to save electronic circuitry, which at present is used to decode and control the input/output systems This decoding could, of course, be dne in the central processing part of the systems centre, but to do so would cause unacceptable interruptions in the main program. If sufficient speed is available, interruption in the program can be accepted, and it is likely that in the future the output mechanism concerned will interrrupt the program, ask for its particular problem to be solved, and the program will then continue. The requirement for larger stores arises from the natural attempt to enable computers, like humanbeings, to benefit from past experience. Although storage is expensive, it may in the long run save money by reducing the amount of programming effort required. The real cost of programming is becoming more widely understood and is a cause of some concern; programmers are in short supplyand are expensive to train. The present trend is to make the programmer’s task comparatively simple, leaving the detailed breakdown to be done by the machine itself. The principle applied is to take the complicated and detailed routine involved in programming some particular operation, such as multiplication, and to store this in the computer. The programmer merely writes down the word “multiply”, for example; this is fed into the machine, which searches its store until it finds the word “multiply” and then automatically carries through the lengthy series of operations required to achieve the object. This system can be applied to many other functions and a comparatively straightforward language used to give instructionsto the computer. An extension of this is to enable the same language to be used with a variety of different computers. This in turn, of course, requires additional storage capacity to make the necessary adjustments for various types of computer. This reduces the programmer’s problem to organising the by means of a series of straightforward instructions. He need not understand or know the complicated machine language in which programs are normally presented at the present time. One disadvantage of this system is that if the machine breaks down it may be extremely difficult for the maintenance engineer to find out the cause of the fault, since the means by which the machine performs these operations need to be known only to the designer.