William van den Heuvel William van den Heuvel
Freelance software developer

IBM mainframe

In 1968, I moved to England. This is when my IT career on the IBM mainframe started.
In 1973, I moved to Munich, Germany working as a systems programmer and software developer for various companies.
In 1977 I became a freelance IT consultant focussing primarily on software design and development.

Following is a brief resume of my experience on the IBM mainframe.
The resume is in chronological order.

1968– 1972
American Express Company
Credit Card division
Haywards Heath, Brighton (GB)
I started my IT career as an application programmer for the American Express Company in England (European Credit Card Division). This was at a time when programming and data processing was still done using punch card machines. The computer was an IBM OS/360 with 16K of memory. There were no discs, only magnetic tape and punch cards. The machine was later upgraded to 32K with DOS operating system. I became the Systems programmer and was responsible for generating the system software and maintaining the System. I also developed software tools for the convenience of the application programming team. After a few years the OS/360 machine was replaced by an OS/370 with 256K and MFT operating system.
(Munich, D)
In 1973, I moved to Munich in Germany and became a member of the existing Systems programming team. The company had several OS/370 machines operating under MVT. I was responsible for the generation, maintenance of the IMS database system, and for providing technical support for the application programming department. At around this time, the IBM/3270 display screens were introduced, and we started using these screen to communicate with the computer directly, replacing the punch cards and endless paper prints.
(Neuaubing near Munich, D)
In 1974, I switched to Dornier in Neuaubing near Munich to help them setting up a new computer department. They had a new IBM/370 and, as the systems programmer, I generated the Operating System VS1 for them. I also provided technical support fort the computer operators and developed tools and standards for the application programming department. I also introduced them to developing application programs using the IBM/3270 display screen and IMS.
(Ottobrunn near Munich, D)
In 1975, I was asked to help IABG to set up their new IBM computer department. This was essentially the same as what I had previously done at Dornier. At this time I became interested in telecommunications and started writing software for the IBM/3270 display screens under control of VTAM.
Own company
In 1977 I started my own company. In those days, programming was stil done using punch cards. But it had occurred to me that it was entirely possible to type the lines of program code on the IBM/3270 display screen and save them on disk as a file. I already knew how to program the IBM/3270 under VTAM. Thus, the idea was born to use a screen and keyword to write programs (instead of the punch card machine). Consequently, I designed and wrote a system called Interactive Programming System (IPS). This was a revolution at that time, and my program was a big success. However, at around the same time, someone else also had the same idea and came on the market with a similar product called "Roscoe". But the market was big enough for the competing products. However, this changed when also IBM introduced its system called "TSO/SPF". Eventually, IBM conquered the market for interactive programming systems and pushed out Roscoe as well as IPS. And sadly, I had to give up my company.
1991 -2001
I had established excellent relationships with satisfied customers who asked if I would do contract work for them. In the following years I started doing contract work and consultancy on a freelance basis, in an area in which I had specialised myself.
I have worked for numerous companies, mostly in the financial sector (banking and insurance) such as Winterthur Versicherungen, HypoVereinsbank, Stadtsparkasse Munich, VVB, but also for software companies such as FJA in Munich and Software Engineering in Dusseldorf.
The assignments were usually consultancy and software design and development on the IBM mainframe. I have programmed in Cobol, PL/1, C and C++ but most of all in Assembler. E.g. I have written a program for Software Engineering GmbH called „Online Transmission Time Optimizer“ (OTTO), which compresses data streams between the mainframe computer and remote terminals. I have also written a „Dynamic Runtime Analyzer“ (DRA) which analyzes the performance of Language Environment conforming applications, as well as a „Web Host Bridge“ (WHB) which connects any TCP client with a concurrent TCP server that runs on the IBM mainframe. One of my lasts projects on the IBM mainframe was a high speed XML parser and generator.