Software Development

D. Ball

As computers have become larger, faster Although, in general, the manufacturer SCOPE. Since this would be used by other and more complex, so have the program• supplies software, it will rarely fit the computers of the CDC 6000 series and ming systems necessary to exploit their needs of a large specialized organization since all future compilers, etc. would be capabilities. The development of these such as CERN exactly. Thus it is necessary written to work with SCOPE, the decision systems ('software') is estimated to cost to adapt and modify the systems locally. was taken to change over as soon as a the manufacturer as much as the con• With the CDC 6600, the situation was suitable local version was available. The struction of the machine ('hardware'). This aggravated because the machine acquired work on this conversion from one operating increase in complexity and magnitude of for CERN was one of the first to be system to another has been carried out the software for the latest machines has produced, and it was delivered without its mainly on the CDC 6400 in recent months arisen because of: software. This made it necessary to accept and it is planned to phase out SIPROS by an incomplete system and develop, in a the end of the year. a) the increase in the speed of the cen• crash programme, together with a local It is also the responsibility of the tral processor (the time to add two CDC support group, the present operating systems section to advise on trends in floating point numbers on CERN's first system which is called SIPROS. Specific software and hardware and to help evaluate computer — the Ferranti Mercury — additions made were : the facilities needed possible equipment for CERN. was 180 [is ; the time on the CDC 6600 to drive real-time devices in parallel with is 0.4 us) has not been matched by To gain experience in some of the new , a sophisticated error corresponding increases in the speed fields, experimental work is in progress, recovery procedure, a program to drive of peripheral devices. In an attempt both on the 6000 series machines and on a multiplexor with teletypes (this synchro• to keep the central processor busy, a CDC 3100. On the former, a symbolic nizes the slow input and output equipment designers have resorted to more and debugging package for checking with the computer), a plotter and a tape more complex stratagems, as, for ex• programs (it allows the user to print out reel number display system (this informs ample, in the CDC 6600 where 10 smal• selected data while the computer is the computer operator which magnetic ler machines feed the main processor working on his program without modifying tape requires loading on the machine), which operates in a multiprogrammed his program) has been developed, and and flexible magnetic tape routines for mode. The co-ordination of these eleven studies of a file manager carried out (which checking special tape labels and processing machines in one must be performed by makes it possible to store programs and various tape formats. software. data in 'files' in the computer from which Since the programs for the analysis of they can be retrieved and modified). A b) the variety of input and output devices bubble chamber experiments are used in group of programmers are developing a on current machines (contrast the laboratories throughout Europe on a system on the 3100 to give an improved range of devices on the CDC 6600 with number of different computers, it was computing service on the 6000 series the paper-tape reader and punch which decided to standardize on a restricted machines for remote on-line users. Facilities were used on the Mercury). The soft• version of the computer language Fortran will be available for transmitting program ware must drive these as efficiently (called CERN Fortran) which was generally and data files to these machines from the as possible, often with several of them available on these computers. It was 3100, and for output files to be returned. sharing an input/output channel. therefore necessary to modify the CERN Users will be able to store files and edit computer accordingly. them from remote typewriters. c) the wide range of applications for which the computer is used ; for example, About the time that SIPROS began to An oscilloscope display is also fitted to on-line flying-spot-digitizers (see be used at CERN, CDC decided to the 3100 so that experience can be gained page 179), real-time programs, and concentrate their effort on the development on possible uses for graphical displays at batch processing. of a different called CERN.

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