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The ICF PRIMEnet was centred on RAL. The sites were clockwise from top-left: UMIST (Manchester), Warwick, Nottingham, East Anglia, City and UCL in London, Surrey and Sussex
HASP and 2780
The initial requirement, in terms of communication, were:
- Allow remote users to communicate with the Prime 400 at RAL. This involved tuning the Prime products to work over UK dial-up
- Allow users to submit batch jobs to the IBM 360/195 and have output returned to them
The main method's of accessing the 360/195 were using the IBM 2780 binary synchronous protocol for connecting a remote job entry station (card reader, card punch, lineprinter) to an IBM mainframe and HASP (Houston Automatic Spooling Program). HASP ran in the 360/195 and handled spooling of I/O and scheduling of jobs. It was originally designed as a one-off for NASA Houston but through SHARE had become widely used to access remote mainframes. The system pretended to be a set of virtual devices on the mainframe which were then shared between the remote job entry stations. The HASP multi-leaving protocol allowed a wide variety of stations running at different speeds to be attached. HASP provided flow control, multiple streams into a single block, compression, error handling, retransmission etc.
The RAL version had been highly modified over many years and supported a set of non-IBM RJE stations and included support for terminals attached to the RJE station as though they were attached to the IBM 360/195.
Graham Robinson modified the Prime products to run in the RAL environment.
In 1977, we had been told that PRIME were working on networking software similar to DECNET but it was 1979 before PRIMENET was finally made available. PRIMENET offered three main facilities. IPCF, Inter-Program Communication Facility, alowed programs running on one PRIME system to establish a communications path to a program on another PRIME system. ITS, Interactive Terminal Support, permitted terminals attached to one PRIME system to log-in to another PRIME system. FAM, File Access Manager, allowed users or programs running on one PRIME to use files stored on other PRIME system in the network. By then, upgraded versions of PRIMOS and Primos support was handled centrally with new versions of the operating system downloaded via PRIMENET.
Later, PRIME provided X25 support so that these facilities were made available to non-PRIME systems as long as they used the appropriate protocols. Initially, RAL was connected to the other PRIME systems using PRIMENET. By 1980, this was replaced by the standard X25 protocols (ITP and FTP) available in SRCNET.