The period 1986 - 1990: DEC systems

The end of the PDP era at TNO-FEL

To reduce the total budget for system hardware and software maintenance, it was decided in the beginning of 1989 that the six to seven years old PDP 11/44 had to be turned off as soon as possible. Despite that, it took almost a year before the last applications were moved to other systems. After the "Construction and Manufacturing" division had moved all his data files to other systems, systems managers started to rewrite the disks of the PDP 11/44 system a number of times using different bit patterns. This according to the existing procedures for declassification of classified computer media. While waiting for the last write pass over the last replacable disk pack, the system manager was approached by a colleague who discussed some issues about the FELBIS Oracle database. After solving that minor problem, he would transfer the MILCA-data (reference database of electronic designs) from the PDP 11/44 to the administrative VAX. Then his colleague could start cleaning....

All the other colleagues were surprised as the disk wiping was almost complete and the screw drivers were already at hand to disassemble the PDP 11/44 in order to free space for new VAXes (see below). The cleaning procedure guaranteed that no usable bits were left at the disk surface, even the sides of the disks were cleaned... In the end, the Milca information was fortunately found on some backup tapes.

New DEC systems

End of 1986, a project team prepared a report discussing various options for the replacement of the VAX 11/750’s by a single VAX 8300 (2 CPUs) or a VAX 8500 (1 CPU) system.
Two complete different alternatives were discussed: replacement of the VAX 11/750’s by a single VAX 8500 or by adding a VAX 8200 to the VAX 11/750-VAXcluster. The three VAX 11/750's comprised the scientific research cluster-VAX (VC), the VAX for administrative purposes (VA) and the VAX for graphical applications (VG). To allow the use of the microPower/Pascal language as well as the Comtal facilities, we had to keep one of the VAX 11/750’s. MicroPower/Pascal was used for the development and support of programs for the PDP 11/23 of the Royal Netherlands Army in Huijbergen which controlled the Universal Dynamobank (UDB-project). That was a robotic designed system in which test programs ran that tested vehicles under various road and driving conditions while moving on a static set of cylinders that comprised the dynamobank.

The Management decided that a strict distinction had to be maintained between the scientific and administrative systems on the VAXes. Both from a standpoint of costs and of bottlenecks that had to be solved, it was decided to replace the administrative VAX at first. The two years old VAX 11/750 was sold to the PML as a replacement for their PDP 11/45 system.

MuseumWaalsdorp@tno.nl