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P. Burgess reviewed the current situation. The HP-1000's were now reaching the end of their useful lifetimes. The MkIV upgrade would soon be underway so now was the time to consider what systems would be used to replace the HP's and control the MkIV DAR and recorder systems.
The MK4 PC system with VENIX operating system was the most general solution. The NRAO VME system software is now much improved and can be used with a VLBA Terminal, but not MK4 as the software protocol is different. The DARFS software (developed initially by Burgess) would undergo further development for a year until the situation became clearer.
As regards the MkIV PC FS: (i) The Venix OS is the major cost. There may be a Public-Domain system in the future, modified by GSFC. (ii) Users will almost certainly need the development software tools for Venix in order to implement site-specific Antenna, TSys, phasecal and timing control and monitoring. (iii) Output logging will need to be developed for VLBA compatibility. Information may ideally be gathered in real-time, but could be added after observing. It is not known yet where the definition for the log format is to be found. (iv) Internet connections will be required to handle the greater volume of schedule and log data to/from AOC/Jive.
P. Burgess wondered whether the PC could cope with both the FS and the cpu intensive PCAL program. Perhaps 2 PC's would be required. M.A. Garrett asked about the frequency and cost of VENIX upgrades. T. Foley beleived the costs to be USD 2000. He was unsure of the frequency. C. Trigilio noted that they had taken delivery of the FS in December 1992 and no VENIX upgrade had been required as yet. M.A. Garrett asked when a final decision had to be made. In view of the schedule for the upgrade J.D. Bregman believed that June 1994 would be the deadline. P. Burgess thought that in the end indivdual sites would have to choose for themselves. M.A. Garrett suggested that all sites should standardise on one system so that the developments at one site could be translated across all the EVN sites. This approach was the key to success for the EVN generally. J. Buiter felt that the upgrade process would be usefully assisted if each site was running the same system. A. Mujunen asked about the present support from Nancy Vandenberg with respect to the HP1000 field system. P. Burgess and T. Foley thought that it had been reasonable over the years.
To summarise P. Burgess thought that the MkIV PC FS was probably the best choice although the cost of the full system USD 17,000 seemed excessive. Most of this cost was due to the VENIX/OS. P. Burgess informed the group that Dave Graham had attempted to ports the PC-FS to run under LINUX - the public domain Unix for PC's. While he had got most of the way some problems still remained. The Metsahovi group were interested in this development. T. Foley was concerned that an attempt to support the FS under LINUX might require a major effort. It was not clear that anyone would be prepared to support the FS (running under LINUX) from one upgrade to the next.
ACTION ITEM: Paul Burges to discuss the possibility of using the LINUX O/S with interested parties
C. Trigilio reported on his experiences with the MkIV system. He had found it a user-friendly package and so far there had been no problems running MkIII SNAP files. P. Burgess noted that Westerbork, Noto and Medicina were now using or had ordered the MkIV PC field system. A final decision had yet to be made at Jodrell, Effelsberg and the associate EVN members.