The RAPC Computer Centre enters the 1970s

(Developments at the Computer Centre)

RAPC Journal 1970


The seventies will bring widespread changes to the Corps and nowhere is this more evident than at the R.A.P.C. Computer Centre. The gaily painted tea-huts of the builders have encroached upon the car-park. The building itself is bursting at the seams as various annexes and extensions are being added. Internally, the North Computer Room has been gutted and is in the process of being rebuilt.

The era of the IBM 705 computers is drawing to a close. One of these computers has already been cast, taken away most ignominiously in a scrap merchant's lorry. The other must go this year. Those of us who cut our teeth and frayed our nerves on the 705s may regret their passing, mindful only of their achievements and forgetful of their faults. Still, the 705s have served their time and well beyond it. Ageing and obsolescent, their place is to be taken by two new IBM 360/50 computers, faster, more powerful and, regrettably, considerably more complex than their predecessors. The first is due to be installed in April of this year and the second a year later.


With the new computers come new tasks, as important and possibly more onerous than pay. The work of the Record Offices, the administration of the Regular and Reserve Army, will be placed on these computers. This is not a proposal but a firm plan. Conversion of the manually maintained service records of soldiers to computer maintenance is due to commence in July. This will be followed by transfer of all the current Record Office EAM (Punched Card Processes) to the computer. And within the next three years it is anticipated that much of the work connected with promotions and postings will similarly be absorbed.

A very natural and possibly justified dislike of cold, calculated computer processes has curtailed the extent of work which the computers will be permitted to carry out on promotions and postings. It has been said of computers that if a problem and the method of solving it is scientific and can be expressed exactly on paper, then the computer can do the job. But computers cannot know what a human being feels or instinctively knows. That Smith and Brown are mutually antipathetic and if posted to the same Unit would cause trouble. That Jones would rather stay where he is than be promoted. Or that Mrs. Smith and Mrs. Brown don't like each other. The computer will only be allowed to prepare short lists of names, leaving the final decision to the Record Offices themselves. The time may come, ,of course, when computers are so powerful and programmers so excellent that the computers can be progammed to know, not only the primary information about soldiers but also the secondary. Not, I hope, in our time. Most people still like a little mercy with their justice.


And now, for the technically minded, a word or two on the new computers. They have Central Processing Units, where the work is done, with a capacity of 524,000 characters-as opposed to 40,000 on the 705. The Processing Units are capable of obeying 145,000 instructions a second, which makes the 360/50 at least ten times as fast as the 705. The tape units transfer data into and out of the Processing Unit at a rate of 120,000 characters a second-eight times as fast as those on the 705.

Soldiers' accounts and records will now be held on permanently revolving disks.


It will no longer be necessary to read from the beginning of a file to find any particular record. Using an index to show where the record is held on disk a reading/writing arm moves across the disk and goes straight to the place. For query purposes or for updating runs, where the activity on the file is low, this method speeds up processing considerably. The total capacity of the disks will be nearly 1,000 million characters and records will be accessible from either computer. The disks themselves can be removed from the drives and replaced by others so there is no theoretical limit to the amount of data which can be held on disks. It will be realised that these are extremely powerful computers and should be quite capable of dealing with the work of Record and Pay Offices, even if all Reservists were mobilised. There is another side to the coin of course. To make the best use of the power of the machine an enormous amount of manufacturer supplied programming is required to act as intermediary between the Records and Pay programs and the computer. This programm!ng, known as Operating System, runs to many mIllIons of instructions, far more than we shall ever write ourselves. It is stated that it represents more than half the total cost of the computers. From the computer side it has proved necessary to set up a special "Software" Group, solely to make it work not to maintain it. " Software" is the trade term for programs, the other linked terms being "Hardware" for the machinery and "Liveware" for human beings implicated.

The capacity of the Central Processing Unit on the IBM 360(50 computer is greater than would appear from the rating of 524,000 characters. By ingenious manipulation of the bits of magnetic flux which make up each character it is possible to make them each hold an alphabetic character, or two numeric characters (00 to 99) or a binary number (0 to 255). The use for binary numbers is particularly significant as it is now possible to hold a calendar date in no more than two characters. This is all very clever until you try to print out what you've got in the computer. There is no range of single recognisable character formats which can represent 256 different numbers. The Chinese could perhaps do it but fortunately the manufacturers have come up with a better idea than all of us having to learn Chinese! They have very ingeniously used two characters to represent each single character in the computer. 0 to 9 represents 0 to 9 and A to F represents 10 to 15. By printing two of these  characters together 256 variations (0 to 255) are possible. For example, 01 represents 1 and FF represents 255 . Some complications arise when the character is truly an alphabetic character. For example, C1 = A or 193. To decide which it is you have to know what kind of character you expect to find in any particular position. It may sound a bit difficult but, in fact, there are some programmers in the RA.P.C. Computer Centre who can actually read and interpret this form of hexadecimal (as it is called) printing. There are also, of course, some people who can't and it is fortunate that these are the more influential. Otherwise the statements and pay slips to be issued by the Computer Centre might have been printed in hexadecimal form which would certainly have caused some alarm and despondency in Units. Now, programs have been written to interpret hexadecimal characters and to permit printing in orthodox fashion. And if you still can't understand the output well, you're no worse off than before. 


Tucked away in the recesses of the Computer Centre are the programmers, slaving away at maintaining the complex programs demanded by the new computers. More vociferous are the testers, desperately trying to prognosticate the fiendish, program breaking types of input Regimental Pay Offices may devise. Overall are the liaison types doing their best to produce coalescence. We would like to think that it will be a brave sight when both of the new computers are in operation. Five printers and two typewriters will be chattering away without break. Run will succeed run with scheduled regularity. Programmers will be peacefully programming. Testers will be tactfully testing. The sun may even shine on Worthy Down. Utopia, at last.