Pop-11 is derived from POP-2, a language originally invented at Edinburgh University for research in Artificial Intelligence. POP-2 was described in
PROGRAMMING IN POP-2
R. M. Burstall, J. S. Collins and R. J. Popplestone
Edinburgh University Press, 1971
Additional information about the history and philosophy of the POP
family of languages can be found in
POP-11 Comes of Age: The Advancement of an AI Programming Language
ed J.A.D.W. Anderson,
Ellis Horwood, 1989.
This includes a long paper by the author of this Primer on the
development of Pop-11 at Sussex University.
The original version of POP ran on an Elliot 4130 computer and is now obsolete. A later version was implemented on the DEC-10 computer running the TOPS-10 operating system in Edinburgh. Julian Davies, also at Edinburgh at that time, implemented an improved version, called POP-10, in the early seventies. Yet another version for the DEC-10 called WPOP (WonderPOP), was implemented by Robert Rae, with some help from Allan Ramsay, and became available in the late seventies. It was also transferred to the TOPS-20 operating system, and was quite widely used for AI research for a while.
Steve Hardy implemented the first version of Pop-11 in 1975. This was a small system which ran on PDP-11/40 computers under the UNIX operating system. It did not include all of POP-2, but had some extra features instead, designed to make it easier to use, especially for teaching purposes. In particular, the pattern matcher, the autoloadable library mechanism and a large collection of help and teaching files made it especially useful for educational purposes, and several Universities and one school in the UK (Marlborough College) used it for some time in the late 70s and early 80s. This version of Pop-11 is now obsolete, and probably unobtainable, though for a while the a version for PDP-11 computers running UNIX version 7 was available from Nottingham University Psychology Department.
The second version of Pop-11, available only since October 1981, and mostly implemented by John Gibson, is much larger and has far more facilities. It includes all the features of POP-2 and many more. However, it requires a computer with a large, `flat' address space, well over a megabyte in size. We correctly predicted in the early 1980s that as the price of hardware fell, it would soon be possible for computers in the home, in the office, and in schools to run programs of the size of the Pop-11 system, and larger, providing a very powerful tool for program development, or for teaching computing. Unfortunately, the horrors of MSDOS and the PC environment preventing porting, as we lacked the resources to do that.
The version of Pop-11 described here, which is available only as part of Poplog, runs on VAX computers under VMS and a variety of different computers running versions of the Unix operating system, e.g. Sun(SPARC), HP, Silicon Graphics, Sequent Symmetry, DECStation, VAX-ULtrix, MIPS, and PC running Unix.