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Correspondence 1961

23.01.61 T G Pickavance to NIRNS Governing Body

Further Details and Proposals Concerning an ATLAS Computer

Brief details of a proposal to site an Atlas computer at the Rutherford Laboratory were given in paper NI/60/14. The following further notes may help in the discussion on January 30th.

  1. The Minister for Science's Working Party took into consideration the following points:-
    1. The AEA have placed a three-year contract for the hire of a Stretch from 1962, but its continued operation beyond 1965 and particularly for more than one shift will be more expensive than the purchase of an Atlas. The performance of Stretch has declined somewhat on original expectations. While it cannot be certain that Atlas will itself come up to present expectations it is considered that the importance of ensuring that a large British computer is produced, taken together with this potential estimated demands provides a strong case for placing an order now, subject to suitable conditions about performance and negotiations of a reasonable price. An order placed now in the U.K. with official backing would also encourage Ferranti's in their attempts to secure further orders in this country and abroad (e.g. from CERN or from American sources which are known to be interested.) Components for computers of greater capacity than Stretch or Atlas are now under development, but it is virtually certain that these will not be commercially available before 1970.
    2. The Atlas is being developed with the assistance of research workers at Manchester University. It is likely that if an order is placed for it, the first machine will be available in 1963 or 1964. It will be approximately 10 times faster than the largest computers now in use or shortly coming into service such as the Ferranti Orion. The Atlas is estimated to cost £1iM to £2M according to the size of the memory store. The memory will in any case be very much larger than that of existing machines. The Atlas is therefore capable of undertaking computation which is either impossible or would take very many hours on smaller machines.
    3. In the estimate of requirement for time on an Atlas quoted in NI/60/14 the AEA's separate requirement for defence purpose was not included. Separate arrangements, including the hire of the Stretch machine mentioned above have been made to meet it. It has been considered whether, for the time being at least, the university requirement could be met by making this Stretch available on a night shift. For reasons of security, inconvenience, the probable continuation of an American monopoly in computers of this calibre, and the lack of a reserve against expanding needs it has been concluded that this solution is not to be recommended.
  2. The Working Party recognised the possibility of a rapid increase in the requirement for Atlas time, which might enable one or more universities later on to make a case for the provision of the Atlas situated in the university. They recommended that a further review of needs should be made towards the end of 1962, in order to see whether a case for the provision of more than one Atlas machine in 1964 then exists.
  3. The Working Party assumed. that the English Electric KDF 9 would be made available to certain universities.
  4. The point was considered important that Ferranti's would be greatly helped in convincing potential customers for Atlas if they had first secured an order from a large organisation in the UK, particularly the UKAEA, who were large operators of computers and had already committed themselves to IBM machines from 704 to Stretch.
  5. The Working Party have now recommended that the AEA should be authorised to place an order for an Atlas machine with the largest size of memory store for delivery in 1963 or 1964, and that if the Institute agrees, it should be installed at Harwell under the control and management of the NIRNS, subject to making an agreed minimum time available to the AEA. Having established their case to use the computer, universities could be guaranteed an agreed minimum of time under their own management.
  6. The Treasury have asked the NIRNS to decided whether or not they are willing to take over the management of an Atlas as proposed. At the same time they have asked the Minister for Science's office to obtain an opinion as to whether there is any legal objection under the terms of the Royal Charter because a substantial part of the use is not for nuclear science. (A provisional legal opinion has been given that there is no objection). Thirdly, the Treasury have agreed that the AEA should begin tentative contractual discussions with Feranti's.
  7. The Institute and its committees are primarily organised to provide and operate accelerators (and large research reactor's when required). Although nuclear science provides a substantial element of the requirement for the Atlas, the known requirements from other fields are at present greater. Special arrangements for the Atlas would therefore be needed.

I suggest that a Computer Committee would need to be formed to advise the Board on all matters concerning the Institute's interest in the computer. It would include several Board members together with computer specialists and users of such standing that the Board and the university users could be expected to find their recommendations acceptable. I suggest that the man responsible for discharging the Institute's function on the computer should report directly to the Computer Committee. I believe that both AEA and NIRNS staff would have to be involved in operating the computer; details of the collaboration between the Authority and the Institute in this matter would need to be worked out.

19.01.61 C J Highton, AEA to R A Thompson

You asked me this afternoon to advise on the position of the National Institute for Research in Nuclear Science in relation to the proposal to install their Atlas computer. The computer will be used, at first, only for a limited part of the available time on nuclear research and related matters. The intention is that other users, particularly universities, shall be allocated time on the machine and you are anxious first of all to determine whether it is within the Institute's competence to allow use of the computer in this way. Secondly, you would like to know whether the matter is at all affected by whether a charge is made for these non~nuclear uses or not.

I pointed out that paragraph (d) of the Institute's Charter is the only paragraph in Article 4 in which no express reference is made to nuclear science. It seems to me that if the National Institute has decided under paragraph (b) to provide a computer, it would be open to the Institute to permit the computer facilities to be used by scientists for scientific purposes falling outside the field of nuclear science. As an example, I think that if the Weapons Group of the Authority wished to use the computer for some research programme into ballistics and the Institute decided that such use of their facilities was appropriate, no question could be raised as to the vires of such use of the facilities. I do not think the word appropriate is to be construed in the narrow sense of meaning appropriate only in connection with research into nuclear science, but is to be read rather as meaning appropriate in all the circumstances of the case within the Institute's general discretion. Obviously one of the points which might move the Institute to consider some use to be appropriate would be the fact that it would be better for the computer and its operating staff to be fully employed rather than to be idle, they might also consider it to be appropriate that scientists generally should be permitted and encouraged to acquaint themselves with the use of computers in the scientific world. This would presumably ultimately lead to an improvement in the range and capability of computers, which in itself would be of advantage to nuclear science.

It does not seem to me material whether or not the Institute decides in any particular case of a scientific use to make a charge for the facilities they are providing. It might be argued, however, that Article 5 of the Charter (which provides that all moneys and property received by the Institute shall be applied solely towards the promotion of the objects of the Institute) indicates that any non~nuclear scientific user ought not to be subsidised by the Institute and that therefore some charge for the facilities provided to non~nuclear scientific users ought to be made.

I notice in Turnbull's paper there is a proposal to let the machine out on hire to industrial firms for non-scientific purposes at commercial prices. A user of this kind would not, of course, be covered by the express provisions of the Charter, but I think that the Institute would not, in practice be challenged if it decided in its discretion to permit such user, without prejudice to scientific interests. The Treasury would not be at all likely to object, as their grant to the Institute would be abated by the commercial receipts and I do not foresee any possibility whatsoever of a private individual such as a disgruntled computer manufacturer complaining to the Courts about this user and being granted an injunction to restrain the Institute from continuing to let out the spare time capacity.

As I explained, it is not my job to advise the Office and in particular I am not (anyhow officially) the legal adviser to the National Institute. It was therefore agreed that I should send a copy of this letter to Woodhouse at the Treasury Solicitor's Office and ask him to get in touch with you if he disagrees with anything that I have said.

06.02.61 J A V Willis, NIRNS to F F Turnbull, Office of the Minister for Science

The National Institute for Research in Nuclear Science have considered the proposal that an Atlas computer should be installed at Harwell under their control and management. I am instructed by the Chairman to let you know that the Institute are prepared to accept this commitment. In recording their decision the Institute added that they considered that they should not charge the universities for use of the computer, either for nuclear science or for any other use.

The Institute were by no means convinced that the proper place for a university computer was at a centre remote from a university, but they recognised that there were special considerations in this case, and they took note in particular of the following points, which were put to them as being the views of the Minister's Working Party.

  1. that it is important for an order for an Atlas to be placed quickly and by a large user of computers such as the Atomic Energy Authority.
  2. that computers such as KDF9 will be made available to certain universities notwithstanding the provision of the Atlas.
  3. that it is assumed that one or more universities may be able to make a case for an Atlas in the University, and that a further review is contemplated towards the end of 1962 to see whether a case for the provision of more than one Atlas in 1964 then exists.

16.02.61 Jack Howlett to Dr F A Vick

The provisional specification drawn up for the Harwell Atlas is for a large-scale installation costing a little over £2.5m. If this is approved the computing laboratory in which it is to be sited will have one of the most powerful machines in the world - possibly even, the most powerful, for there are indications that Atlas may turn out to be a better machine than its only rival, the IBM Stretch. Thus, this laboratory will have a most serious responsibility, that of ensuring that the best possible use is made of a major scientific asset; and as the fields of application of mathematics have been widening and diversifying with rapidly increasing speed since the digital computer became an accepted tool - that is, over the past 5 years - we cannot predict what will be the most important problems to be put on to the machine in 5 years time; therefore the laboratory must be prepared for anything. I want to give here my views on the way the laboratory must be staffed if this challenge is to be met.

In the collaborative scheme, which seems to have been accepted, the laboratory will have to provide various services for a variety of customers, and will belong to Universities, Research Institutes, Government departments and the AEA; these are:

  1. Time on the machine
  2. An operating service, including all necessary data-preparation
  3. An agreed set of programming languages and the necessary input systems; this includes such things as FORTRAN compilers
  4. Teaching in programming
  5. A pool of knowledge of numerical mathematics (a term to be interpreted very broadly), always kept up to date
  6. An intelligence service for trends and developments in programming, in all parts of the world
  7. A similar service for uses of big computers
  8. To an extent not yet clear, the actual writing of programs for customers.

This will require the following staff groups:

  1. Engineers for maintenance - almost certainly Ferranti staff
  2. Operators and any necessary clerical staff, controlled by a machine room manager
  3. Program-advisory staff for general day-to-day services
  4. Expert program-advisory staff, able to deal with the most sophisticated problems; including people who know all about the inner workings of the compilers and other master programs.
  5. Mathematicians and mathematical logicians, including some of very high grade; most, but not necessarily all, to be interested in numerical aspects.
  6. In addition, to keep the whole group in good health and to counter any tendency towards computation for its own sake, there should be close contact with users, and therefore applied mathematicians working on a variety of problems: these could provide the programming service.
  7. Researchers working on their own problems.

I feel very strongly that all these people should be together in the computer building; computation brings one into contact with all kinds of people and a balanced group is necessary to give the right climate. I am strongly opposed to the suggestion, which has been hinted at, that the laboratory should confine itself to operating the machine - items 1 and 2, that is - and leave everything else to the users; this would be disasterous to the success of the project and is equivalent to a suggestion that the new synchrotron should be run by a group made up of the maintenance engineers and a few clerks to keep the books.

The size of the group, excluding the maintenance and operator teams, which can be settled on straightforward considerations - will need some discussion; it should not be too small, for there must be plenty of scope for interplay of minds; and a fair rate of flow through the group should be encouraged by having several posts for Fellows or Research Associates. I would suggest something around 30-40. A very much more serious subject for discussion is the future of the Harwell computing group; does this become part of the new organisation or does it become just one of the customers? The first alternative leads to difficult problems of control and responsibility, the second will cause a serious decline in the health and status of the group. The question will have to be resolved quickly, for there is a very great deal of work to be done, in all fields, in setting up the installation and this will not go well unless the final outcome is clear from the start. I favour the first course, with some very hard thinking to decide the form of organisation which will meet the undoubted difficulties.

02.03.61 Jack Howlett Note to Marshall, Pickavance and Lance

The Atlas Installation

First of all, I cannot see any good reason for its forming part of the Harwell Theoretical Physics Division; I think my group has gained greatly in the past from this association even though we have led a fairly independent existence, but with a new building (outside the fence) and much wider responsibilities, the links in future will be so tenuous as to be meaningless. So let us consider it as a Division, with a number of Groups.

The laboratory will have these responsibilities:-

  1. Running the computer; in this I include everything implied by the need to get work done quickly and efficiently - provisioning the installation, scheduling, operating, data preparation, distribution of results, keeping the accounts; no customer should need to punch tapes or cards or actually run his program and in fact we would not want to encourage this. Ferranti engineers will maintain the machine.
  2. Providing a computer service, as we do now; there will be three aspects of this:
    1. the open shop: providing the compilers, such as FORTRAN, and all necessary teaching services to able scientists to write their own programs;
    2. a general day-to-day service, helping and advising people who are writing programs,actually writing small-to-medium programs for those who have no time or inclination to do this;
    3. programming large-scale problems, where the job becomes a professional business. Actually, writing compilers and designing operating systems comes into this class.
  3. Mathematics. I feel very strongly that there needs to be a really first-class group of mathematicians in the Laboratory; not only experts in numerical analysis but also people with wider and more academic mathematical interests, particularly in modern developments. One or two mathematical logicians could very well be included. Apart from the need to keep the whole outfit in good general mathematical health, there is the certainty that a machine as powerful as Atlas will not be properly exploited unless the proper mathematical climate is created.
  4. Visitors. I would very much like there to be people working in the laboratory on their own problems, in any field of science, for anything from a few months to a year; they would be using the laboratory's services as an aid to researching whatever goal they were seeking. Just as physicists come to use the accelerators. these people would come mostly from Universities and would help to keep the very desirable contact with science in general.

This means that one wants this kind of organisation:

  1. Division Head: with secretarial and clerical staff and probably a DAO.
  2. Group Leaders:
    1. Machine Manager: with operators (computer, data-preparation, and data-transmission links), a clerk for records and accounts, and the maintenance engineers answerable to him.
    2. Computing Service: programmers and mathematicians, of SO, EO and SA grades. This group will have two fairly distinct functions: the day-to-day work and the large-scale work including what might be called program research. I think it better to keep it all together; equally I am inclined at the moment to include the rather specialist activities of statistics and data-processing, though these could form a separate group.
    3. Mathematics: this group would consist solely of Fellows,Research Associates and SOs - I would suggest that at least half should be on short-term (3 years?) attachments.
  3. Visitors: these should need nothing more than accommodation and access to the laboratory's services. They would not be on the laboratory complement.

My estimate for the size and composition of the staff are these:

Division Head and 3 Group leaders, or 4 if Statistics and Data Processing is thought to merit a separate group.
Machine Group
Most of the staff will be non-professional, in the Machine Operator class, although it would probably be an advantage to have a few in the EO class. For the day shift, 3 to run the computer, 4 for data preparation, 3 to operate data-transmission links making 10 of which 2 could be of EO class. For the evening and night shifts (when run), at least 3 to run the computer, possibly 3 more for the other tasks; allowing 1 EO for each of these shifts, we have the limits for the total operating staff for 3-shift working as from 12MO+4EO to 18MO+4EO. There will probably be 3-4 engineers per shift, who will be Ferranti staff; 1 clerk will be needed.
Computing Services
Day-to-day service: 6-8; Statistics and data-processing:8; Advanced programming:10 making 22-26.
Fellows and associates: 4-6; SOs 4-6 making 8-12.
We should allow accommodation for about 8 at any one time.

In addition there should be two secretaries (one for the Division Head, one for the Group Leaders) and 2 typists for mathematical and general typing, also a DAO - who might, however, be shared with another Division or a part of the Institute. The totals are, for 3-shift operation:

Type Division
Mathematics Totals
Scientific 1 5 23 - 27 9 - 13 38 - 46
Clerical and admin 5 5
Operator 12 - 18 12 - 18
Totals 6 17 - 23 23 - 27 9 - 13 55 - 69
Visitors 8

For comparison, the present complement of the Harwell Computing Group is 26 Scientific + 10 Operator staff and 1 secretary.

Administrative Arrangements

The question of formal control of the laboratory staff presents a difficult problem. The laboratory is intended to serve the AEA, the National Institute, the Universities and some Government departments; at the time of writing, it is being said that no charge is to be made to Universities for time on the machine. The AEA research Group will be dependent on the new laboratory for its computing service and must therefore have its needs and rights very carefully protected. To get a rough estimate of the cost of running the installation, let us suppose that the computer, costing £2.5 million, is written off in 5 years - a pessimistic view; that maintenance costs £150,000 per year; and that the staff costs are equivalent to 50 people at £5000 per year each. Other costs - depreciation of the building, power - are likely to be small in comparison. We get £500,000 per year; this can be exhibited as £180 per hour for time on the computer, for 3-shift working at 5000 hours per year.

There seems to be three ways of organising things:

  1. All staff belong to AEA, who pay all costs. Users are then charged for machine time at an agreed rate; the University use could be covered by an annual payment by the UGC to cover an agreed total allowance of time. For the equivalent of a full shift this would be around £300,000 per year - a sum for which, presumably, the UGC would make a special petition to the Treasury.
  2. All staff belong to the AEA except for the Mathematics Group who belong to NIRNS. The charging process is as before but the cost of the Mathematics Group is borne wholly by the Institute.
  3. All staff belong to NIRNS who pay all costs. This is the opposite of the first; there is no payment by the UGC but the AEA has a contract for so much machine time and the services of so many programmers. Other users are charged by the hour as before.

These are some sketchy statements with a lot of difficulties glossed over; I would like to discuss the problem a great deal more.

12.05.61 Sir William Penney to F F Turnbull

You enquired whether the Authority would be willing to enter into a scheme which would enable university people to have computing done by Authority machines, until such time as Atlas becomes operational.

The question came at an awkward time because we had just received official confirmation from the I.B.M. Company that Stretch would not be as powerful as we had believed when we signed our contract with them. We have now negotiated a new contract the outcome of which is satisfactory to us in that we can still get our important defence work done, and our civil work as well, at the same cost as we originally estimated. In addition, our minimum financial commitments have been reduced. One disadvantage, however, is that Stretch will be about three months late and will not be operating until May of next year. Because of this delay the 7090 will not leave Aldermaston until about June, but it should be running again at Risley by July.

Since Stretch will be slower than we had hoped, the Authority will be using more hours per week than was expected, and for this reason, and because of the three months delay, cannot offer as much computing service in aid of the universities as would have been the case but for the recent changes. We can, nevertheless, still make an offer, which might be attractive.

On Stretch, we could offer up to half a shift (i.e. twenty hours) per week, starting late July 1962 and continuing for about two years, by which time Atlas should be ready.

On the 7090, the maximum we could offer would be an average of one shift (i.e. forty hours) per week up to the end of 1962, and an average of half a shift (i.e. twenty hours) per week in 1963.

If these offers are accepted, the Authority will be running both machines to their maximum capacity.

While we believe that we could undertake on the Stretch and the 7090 as much work on behalf of the universities as stated above, we must, of course, reserve the right that if an emergency computing job for the Authority arises the university work will have to be deferred for a time. We would, nevertheless, do everything possible to carry out the university work to the limit of our offer such as, for example introducing some delay into those Authority computing jobs, which had no urgency.

From our experience on computing we would not be surprised if some of the university requests for work to be done on Stretch or the 7090 would not be better handled by a smaller computer, such as a Mercury, in which case they should certainly be done that way. There is a Mercury at Harwell and we think we could fit in a few jobs for the universities on this machine. (in due course, we expect to dispose of this machine, but we shall keep it at least until the Atlas is running).

In making the above proposals the following points have been taken into account:

  1. By using the services of the National Institute as proposed there will be no need for a university user to have direct access to Stretch or the 7090. (We already operate this type of service within the A.E.A.) For security reasons, it will be necessary to preclude direct access to Stretch; but there would be no difficulty in allowing a university user to have access to the 7090.
  2. If the computing demands from the universities become too many for the Authority to handle there are other machines in the country where time might be hired. At Manchester, the first small version of the Atlas computer is expected to be working early in 1962. This will nevertheless be a powerful machine. Other machines of a very large capacity include those, which are operated by I.B.M. in London (7090), Winchester (709) and Paris (704). The Paris machine is in fact used by I.B.M. for a good deal of its British computing service and it therefore seems reasonable to include it in the present remarks. The C.E.G.B. have an I.B.M. 709 and we understand they have been considering supplementing this with a 7090. Another machine which will be of interest to British universities is the 709 at C.E.R.N. at Geneva on which it may be possible for our universities to buy some time. The National Institute Computing Committee will of course know what is available and would be able to make suggestions at the appropriate time.

An organisation will be needed to co-ordinate arrangements for getting the work done. In considering the organisation, three periods have to taken into account. First, the next two or three years, when university work will be done on Authority machines. Second, the next two or three years, when the Atlas will be installed and will be doing a good deal of university work. Third, a period when universities will be acquiring Atlas computers and the university load on the first one may decrease. In this third period, the Authority will in all probability have more work for the machine.

An organisation which commends itself to us for the first period would have as its Head a man now at Harwell. This man would have the general oversight of all computing, including Harwell work. He would take his broad directions on the work for the universities from the National Institute Computer Committee, and he would be responsible locally both to the Director of the Institute and the Director of Harwell. It would be his responsibility to see that the university work, approved and accepted by the Institute Computer Committee during the period before Atlas is available is done on Authority machines, or if necessary, on other machines.

The Director of Harwell would keep together his teams for programming and operating Mercury, but the Institute would set up a small team for advising and helping the university people to programme their problems. Where there is "debugging" of programmes to be done, the National Institute staff would give any advice or service required, consulting the primary customer if necessary.

When the Atlas arrives, the Head would become an Institute man, although if he were from Harwell, he would remain on the Authority's books, seconded to the Institute. Harwell would keep its own programming team but the operating staff would be transferred to the Institute. The Institute would also have its own programming team, in order to programme its own work, and advise users, other than the Authority.

If there is a third period, where the university work moves to university machines and the main user is the Authority, the machine might be transferred to the Authority, and the Authority would provide a service to other users. The plans being made are sufficiently flexible to be able to permit an adjustment along these lines, should this appear desirable at the time.

Obviously these suggestions will require the Directors of the National Institute and of Harwell to take action in the near future. Conversations have taken place between them and both agree with the suggestions made above. The suggestions now being made are also consistent with the proposals being made in a paper by Pickavance and me to the Board of the National Institute.

With regard to the financial arrangements on the use of Authority machines for university users, we shall have to rely on you to persuade the Treasury. We consider that the Authority should be reimbursed by the actual amount that the service costs us. In other words, we would not ask for standard commercial rates. A suggestion which might be acceptable to everybody is that our charges should be about the same as those made to Authority users; namely a pro rata payment for the direct cost of the machine including overheads. For your guidance these costs would be about £335 per hour on Stretch and £120 per hour on the 7090. (We understand unofficially that I.B.M. will be offering a 7090 commercial service by July of this year and that their rate will be £250 per hour. Our quotation is lower than this because we have a guaranteed large usage by the Authority, we spread the costs evenly and of course we shall not seek to make a profit at the expense of the universities).

We would not wish to quote a maximum time or rate for the use of the Mercury at Harwell, but I suggest that some financial provision might be made for such work in case it should arise. We would expect to charge on the same principle as for Stretch and the 7090. Financial provision of £10,000 for the 1962/63 financial year should be enough to test the market.

F A Vick to H J Millen, UKAEA

Since receiving your letter of July 25th we have reviewed our forecast of the use the Research Group would make of the N.I.R.N.S. Atlas computer.

The estimate of 25+ hours a week was based on a series of deliberations by the Authority Computer Policy Committee during 1959-60, and was reached about a year ago. It was a rough estimate, and it is difficult to be more precise now, but it is already clear that the estimate is very probably too low. We would now put the figure at somewhere between 30 and 40 hours a week. The principal areas of use are (a) reactor physics, (b) solid-state physics, (c) plasma physics (Culham Laboratory etc.), together with a variety of miscellaneous uses adding up to between 5 and 10 hours a week. As far as we can see none of these areas are likely to be affected to any material extent by cuts arising from national economic developments.

I presume you have asked the Rutherford Laboratory of N.I.R.N.S. for its own estimate of future computer requirements (the earlier estimate was about 8 hours a week on the Atlas), but, judging by experience at C.E.R.N., Berkeley (U.S.A.) for example, the Rutherford Lab. Orion will have heavy demands upon it, e.g. for bubble-chamber track analysis, and the use of Atlas will increase.

As I understand it, London University propose to spend initially about £1,550,000 on a basic configuration which they call Atlas I, and to add later further equipment at an additional cost of £450,000 to form Atlas II. I do not know what provision has been made in these figures for a contribution towards the development charge. If by any chance the N.I.R.N.S. Atlas is deferred, a larger proportion of the Ferranti development charge will presumably fall on the London Atlas. The costs I have quoted are for the machine alone, and do not include anything for building and services, but I understand these should not be large since some houses in Gordon Square are available and would need only modification and additions.

To finance the computer, London University budgeted for a £500,000 grant from the treasury through the UGC, £500,000 advance plus one quarter of the operating costs from an industrial concern in return for 1,250 hours a year use of the Atlas for five years, leaving £1,000,000 to be borrowed from the Midland Bank.

London estimated the computer operating costs to be £165,000 a year. I am sure this is too low, quite apart from the fact that no provision has been made for amortisation or overheads (building maintenance etc). On the figures given the industrial concern would be paying £100,000 + £41,000 = £141,000 a year for 1,250 hours use. At approximately £115 an hour this is a heavily subsidised rate. We estimate that the minimum inter Group paper charges that we could make for the use of the NIRNS Atlas (getting on for twice the size of the initial London one) would be £350 an hour on present prices, and commercial rates have been estimated at between £500 and £750 an hour. This means that a fair price for the London Atlas hire by an outside user would be not less than £250 an hour and probably appreciably more.

Since London University will have to sell time not used by themselves or the privileged user, they will not be able to permit other universities, eg Cambridge, to have time free of charge. Thus these universities would use the NIRNS Atlas according to the arrangements already agreed by which the use will be free to university, Thus if both projects go through, the loss to the NIRNS Atlas would be only the projected London University use, The present trends indicate that this loss will be made good by other users not long after the NIRNS Atlas is fully in commission.

I presume the Office of the Minister for Science will obtain the UGC views. As you will appreciate, some of the information I have given above is in confidence.

31.10.61: K.P. Varney to C.M. Wilson

Atlas Performance Tests

I have received from Dr Howlett a minute suggesting the type of performance test which we ought to impose upon the Atlas machine. His suggestions are as follows:-

1. Basic Operations

1.1 A simple loop of floating-point additions:

  1. Not B-modified
  2. Singly modified
  3. Double modified

Similar loops for subtraction, multiplications and division.

The same loops including (n,B) instructions alternating with the arithmetical instructions.

1.2 A loop to form the scalar product of two vectors.

1.3 A loop to evaluate a polynomial

The timing for these shall not exceed those computed from the figures of Col. C. of the tables in Dr Wilson's letter of May 19th.

2. Effect of peripheral transfers

The above programmes to be run whilst peripheral transfers are taking place; that is, transfers to or from any combinations of the following:

The loss in effective computing speed, due to the peripheral transfers, shall not exceed the figures given in Dr Wilson's letter of June 2nd.

3. Complete programme

A programme to invert a (large) matrix, using a specified method. This is to be run with and without peripheral transfers in process. The time for this programme will be computed in advance.

All these programmes will be written by Ferranti's in collaboration with A.E.R.E. and we will formally accept an agreed set. The precise method of timing will have to be agreed.

Will you please let us know whether you can agree with this suggestion fairly quickly or whether you will need time to study it and possibly to make suggestions for change.