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The period 1989 - 1994: DEC systems

DEC VAXes 6310 and 6410 on the background,

the TA90E on the foreground at the right
DEC VAXes 6310 and 6410 on the background,
the TA90E on the foreground at the right

Op Juli 13, 1989 the VAX 11/750 for scientific work (VC) was replaced by a VAX 6310, that was better fit for the purpose of providing central VAX/VMS-capacity for scientific calculations. This system, as main server of the cluster, provided central VAXCluster services as well. The configuration included a new type of disks: the SA600-disk array with RA90 (1.2 GB) disk units.
The VAX 11/750 was exchanged with our collegues of Dienst Grondwaterverkenning TNO for CDCnet equipment that they did not not use anymore after putting their CDC CYBER 810 out of use.


Courtesy Fredi Ferrari, Fides, CH

End 1989, the FEL financial department predicted that the VAX 8350 would lack the required performance for running planned new FELBIS-applications. They estimated that they needed a new system by the mid of 1990. End of June 1990, the FEL management decided to replace the VAX 8350 by a VAX 6410. At the same time, the VAX 6310 for scientific applications was upgraded to a VAX 6410.

Installation the 2* VAX 6410, the TA90E at the right

Less operator intervention

The new Equipment management and IT-services department (Apparatuur, IT-Voorzieningen en Instrumenten or AITV&I) convinced the FEL-management that the management of computer systems required automation. Apart from the backup jukebox connected to the CDC 4380, AITV proposed the installation of a TA90-tape unit. The TA90 could automatically exchange twelve IBM-3480 cartridge tapes (200 Mbyte a piece) that were placed in twee stackers. An acquaintance that worked with IBM told us that a new version of the 3480 tape cartridge unit would be equipped with a data compressioin option. This would allow up to 600 MB per cartridge for backup data. We increased our pressure on the DEC sales representatives.

After many discussions, the FEL was the first one in The Netherlands that had a TA90E-unit (as DEC called the original IBM unit with data compression) for the same price as the original offer for a TA90. DEC did not hide thne original manufacturer well. In the inside of the unit door, an original IBM disk with controller software could be found. Using other "in-side" information, a new type of combined disk/tape-controller, the HSC5X-DA became part of the contract as well.

A free-running CPU-pin

The first experiences with this new HSC5X-DA controller were bad. After two days, the controller vgirtually breath one's last: the disk units and the tape-unit slowed down with a factor 1000 or even did not react anymore at all. A replacement controller card worked only one day before giving up with the same type of problems. At the same same day the equivalent controller in the other VAX showed the same trouble. DEC had not that many spare controllers available in their European spare parts and repair center in Nijmegen. Moreover, the repair center could not reproduce the problem immediately. In the US report came in that other customers experienced there the same kind of problems.

Finally, it was discovered that the controller card contained the complex VAX6000-CPU of which a number of CPU test pins were not connected to a ground signal level. Whenever the free-running pin picked up some static signal, a CPU-interrupt occured. As there was no interrupt software code available to handle the situation, an endless loop occured. After a couple of troublesome weeks, the problems were resolved. In this way, the FEL acquired very modern central VAX-facilities and could provide adequate services to its users.



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