10, 9, 8, 7, 6, 5, 4, 3, 2, 1

posals and costing, was a good way to lose out on a bid and its often considerable funding.

This was not going to be a good day for the guys down at the NASA SPAN computer network office.

This was not going to be a good day for John McMahon.

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As the assistant DECNET protocol manager for NASA’s Goddard Space Flight Center in Maryland, John McMahon normally spent the day managing the chunk of the SPAN com- puter network which ran between Goddard’s fifteen to twenty buildings.

McMahon worked for Code 630.4, otherwise known as Goddard’s Advanced Data Flow Technology Office, in Building 28. Goddard scientists would call him up for help with their computers. Two of the most common sentences he heard were ‘This doesn’t seem to work’ and ‘I can’t get to that part of the network from here’.

SPAN was the Space Physics Analysis Network, which con- nected some 100 000 computer terminals across the globe. Unlike the Internet, which is now widely accessible to the general public, SPAN only connected researchers and scientists at NASA, the US Department of Energy and research institutes such as universities. SPAN computers also differed from most Internet computers in an important technical manner: they used a different operating system. Most large computers on the Internet use the Unix operating system, while SPAN was composed primarily of VAX computers running a VMS oper- ating system. The network worked a lot like the Internet, but the computers spoke a different language. The Internet ‘talked’ TCP/IP, while SPAN ‘spoke’ DECNET.

Indeed, the SPAN network was known as a DECNET internet. Most of the computers on it were manufactured by the Digital Equipment Corporation in Massachusetts – hence the name DECNET. DEC built powerful computers. Each