The PLL Research Project at ICL

While employed as a research officer in ICL's Future Systems Department Joachim implemented (in 1989) an active constraint handling module for a logic programming language (PLL). This research project and the exposure to the internals of ICL's commercial constraint handling system CHIP (later marketed as Decision Power) provided a good foundation for the subsequent work on scheduling systems that has become a focus of Joachim's work up to the present.

Also while based in the Future Systems Department in Bracknell (United Kingdom) Joachim ported parts of the X Window system to ICL's new DRS6000 Unix server, which at the time (1990) was the first implementation of Unix System V Release 4 (SVR4) on a Sparc RISC architecture.