computer systems I have used
1981 I build my own Nascom 2, and created one of the first computerized telex machines, using Nascom basic and the infamous Nascom editer
1983 I wrote a full accounting system in FORTRAN that was running on a Harris 100 computer.
1984 I got employed by the Kuwait Petroleum Refinery in Rotterdam.
my first job was the creation of interactive input screens in HP basic to replace batch punch-card input for the batch IBM system.
At Kuwait Petroleum I was maintaining their batch oriented COBOL and RPGIII programs running on IBM in house hardware and in service at IBM Nederland.
The legend is that one owner of Kuwait Petroleum was sitting next to Ken Thompson during a long international flight. The interesting result was that from then on managment was forced to leave the IBM eco system and move all systems over to AT&T 3B2 systems running UNIX. This totally changed my life and carriere.
Soon we started to use UNIX workstations running SCO on the IBM PC. At some point we met with Andrew S. Tanenbaum, and shortly I was using an early version of Minix. Very soon however, Linus posted the first version of Linux to the minix usenet group, which I started using on my personal IBM Clone at home, and later also in the office.