First was the 5973A, then 5973 Inert, then 5973N and now the 5975 and 5977 MSD. In the early days, the 5973s were still under the HPIB protocol. That meant that the old tried-and true HPIB boards and cables were an integral part of the system. HPIB was rather difficult to install but once in place was always ROCK SOLID ! This of course required an HPIB board in your PC, an HPIB board in your 6890 Gas Chromatograph and Autosampler and also an HPIB board in your Mass Spectrometer.
When networking became common in the office, it naturally extended itself to the Analytical Laboratory. For much of the same reasons that "network printers" became popular - so did "network instruments". Here were the factors that drove the change: Ease of set up and a common environment (IT personnel with Lan experience are easy to find... HPIB experience not so easy to find). Communication by Ethernet is much faster and reliable. Lan instruments can be MUCH FURTHER away from the PC. How many labs have instruments on one bench, but the PC on another bench across the isle or across the room ? Ethernet made that EASY ! Ethernet cables are much easier to route and much neater.
...