Alan Curtis

Alan Curtis of Redbridge, Ilford, Essex had extensive experience of programming, analysis and different systems and of designing, developing, testing, debugging, maintaining and documenting operating systems, utility programs, programmer's tools and commercial applications on mainframes, mini- and micro-computers using assembler and high level languages.

He was a skilled problem solver and communicator, an accomplished motivator, coordinator, advisor and manager. Considerable experience of drafting technical reports and specifications; reviewing documents for ambiguities, conflicts, omissions, and shortcomings; identifying and planning tasks to be performed; submitting feasible proposals to management for consideration, running meetings and operating equipment. Apart from his early days as a self employed Computer Consultant & Reseller marketing desktop computers and software packages, he developed bespoke software, used Word for Windows for word processing and taught others to use it. Provided help, support and advice for a caterer's order processing system.

From 1975 until 1991 he was a Systems Programmer at the UNIVERSITY OF LONDON COMPUTER CENTRE. He maintained and enhanced the Scope 2 operating system (OS) of the Control Data Corp. (CDC) 7600, the largest of four linked machines. Analysed large memory dumps to ascertain cause of system crashes and liased with hardware engineers to pinpoint problems. Produced fixes for bugs in the OS, Editor, Assembler, utilities and various language compilers, reporting these to CDC. Wrote source code modifications to the OS to provide extra functions. He was lead programmer converting the accumulated modifications for new OS releases. Built and tested modified OS prior to handing system over to Quality Assurance department for soak testing and final release to users.

He wrote job control procedures and various utility programs in ASSEMBLER, FORTRAN, PASCAL and SNOBOL for purposes such as (a) automating the build of the OS and program products and producing microfiche listings; (b) running large numbers of batch jobs to test the OS and to subsequently collect their job output files from which success/failure summaries on microfiche were produced to facilitate further regression testing; (c) administering the system, e.g. automating file backups and restores.

In 1980, a Cray 1 and Amdahl front end replaced the CDC machines and he performed similar functions with IBM's MVS operating system on the Amdahl - learnt the internals of MVS and interpreted memory dumps to ascertain problem causes; wrote ASSEMBLER modifications to MVS's job entry subsystem, many job control language (JCL) procedures, time sharing option (TSO) clists, Phoenix procedures (Cambridge University's command language) and programs in ASSEMBLER, PASCAL and PL/1. Used IBM program products such as DFEF, DFDSS, RACF, SMP and non IBM products DMS and OMEGAMON. Recommended ACF/2 replace RACF and helped install it to provide de-centralised system and file access security functions. The ACF/2 database was utilised to implement an online realtime accounting system and a machine resource sharing system that controlled batch job priority and online response time to ensure equitable use among the machine's 6000 users. When a Cray X/MP and Amdahl 580/300 replaced these machines, he converted some of the MVS modifications to function on the replacement MVS/XA operating system.

In 1989, IBM's VM/XA operating system was installed to replace the MVS/XA service. Learnt the internals of VM/XA, gained experience of using VM and CMS commands, the REXX command language and wrote various REXX functions in assembler. Installed the Kermit communications program on the Amdahl under VM/XA and while testing the file transfer mechanism to and from IBM PC's, learnt to use MSDOS on PC's. In September 1991 the Cray and Amdahl were replaced by a Convex system running UNIX. Learnt to use UNIX commands and write Shell scripts.

During his spare time from 1980 to 1982 he gained extensive experience of Z80 micro-computers running under CP/M and wrote an accounting system (sales, purchase and nominal ledgers), in BASIC and ASSEMBLER, for a client.

In July 1984, he installed an Onyx C5001 computer system in his brother-in-law's business and tailored the BASIC and COBOL programs for the company's use.

In Aug 1991, he purchased an Acorn UNIX workstation and learned to program in C and wrote various utilities for his own use.

From 1973 to 1975  he was a Senior Systems Programmer for  APPLIED COMPUTING & SOFTWARE (ACS), London  contracted out to an ICL & Logica led project at the Bank of England where he wrote application modules in PLAN (assembler) for their Government Stockholders Registration and Dividend Payment on-line system on their ICL 1904A's. Wrote various utility programs and George HI macros and developed a version control system to automate -both the handing over of tested modules by application programmers and building new releases of the system for the integrated system testing team. Helped to write a PLAN program to produce an intelligent and symbolically annotated memory dump listing of a crashed system.

At ACS, learned to program the ICL System 4 in ASSEMBLER. Joined an in-house project and wrote modules for an assembler and linkage editor for the BCL Molecular 18 minicomputer.

Contracted out to a shipping agent to write modules in PLAN & COBOL to enable non-standard format magnetic tape to be produced by a set of application programs. Learned to program the Singer 10 minicomputer in its ASSEMBLER. Learned IBM 370 ASSEMBLER and wrote some ASSEMBLER modules for COBOL programs being developed for a client converting from an IBM 1400. Read DEC PDP/11 manuals in preparation for my next assignment.

June 1973 to August 1973 he was a Freelance Programmer at INTERNATIONAL COMPUTERS LTD (ICL), Kidsgrove, Staffs. He wrote programs in PLAN on their ICL 1904S from a printed circuit board parts list explosion and bill of materials system. Gained experience of using the George III operating system.

1971 - 1973     Computer Programmer
Wrote a disassembler in ICL 1900 PLAN for translating Elliot 803 binary programs on paper tape and used the listings to produce program flowcharts for a system specification for a bill of materials and parts explosion program for a window manufacturer who had mislaid all program source code.
Gained experience of driving multiplexors and teletypewriters at a basic level on ICL 1900's and wrote amendents to a large on-line simulation program written in PLAN on an ICL 1904E, which interfaced to a display console driven by a DEC PDP/8 via a communications front end processor. The console displayed vehicle positions on digitised road maps, and the simulation program plotted the paths of the vehicles along roadways.

Oct - Nov      RICHARD COSTAIN LTD., London.  Freelance Programmer
Designed and wrote programs for a costings and estimating system in PLAN on their ICL 1900 machine.

Jul - Aug 1971      SECURICOR LTD., London 1971 Freelance Operator operating their ICL 1900.

1968 - 1970      INTER-BANK COMPUTER BUREAU (now BANKERS AUTOMATED CLEARING SERVICES), London, Computer Programmer. Designed and wrote programs in PLAN for their credit and direct debit clearing system on their twin ICL 1904E's. Gained much knowledge of programming the ICL 1900 at the most basic level whilst writing a very large program to sort over a million records using small disc capacities and producing non-industry format magnetic tapes.

1967 - 1968     RICHARD COSTAIN LTD., London Freelance Programmer Maintained, tested and debugged a personnel records system written hi PLAN on their ICL 1904.

1966 -   1967     JOHNSON MATTHEY& CO. LTD., London Computer Programmer
He wrote general financial application programs (e.g. purchase/sales/nominal ledgers & analyses) in PLAN on their ICL 1902. Developed a report generator program, written in PLAN, driven by run-time parameters detailing record formats, print layout, sub-totaling required, etc.
Wrote FORTRAN programs to produce results of research experiments, and a PLAN program to produce tables of hole sizes that could be cut by a machine using various sizes and combinations of cutters.

He was a Member of the Data Communications and Natural Language Translation Specialist Groups of the British Computer Society (BCS) and Treasurer of the Software Engineering (formerly Systems Implementation Languages) Specialist Group of the BCS for the fifteen years of its existence (until 1989).

The Centre For Computing History is extremely grateful to the late Alan Curtis and his family for providing an extensive library of manuals and documentation related to the computer history of the United Kingdom.