We had anticipated to replace the central computer, a VAX-3100 from DEC, by an HP workstation, in order to provide a possibility to perform a posteriori phase correction on short time scales. Software preparation of this major change has been progressing well, but unfortunately major hardware components are still missing. In order to avoid immobilizing the interferometer in winter time, we now have decided to keep the VAX-3100 for this winter.
Software modifications have been implemented to allow real-time atmospheric phase correction based on the monitoring of the total power from the 1.3mm receivers. Due to CPU limitation in the correlator microprocessors, this is only possible for the 80 and 160 MHz bandwidths. More powerful processors had been ordered, but their installation was delayed because the delivery of software components was blocked by the December Post Office strike.