EDSAC Initial Orders(ID:3411/eds002)First ever assembler systemAssembler with abstraction designed by Wheeler for the EDSAC computer. EDSAC was based on EDVAC, and the Intial Orders system was the first Highish-level (ie faintly abstractive) language for a Von Neumann architecure machine. IO was hugely influential in developing the first generalised languages. The "Initial Orders" allowed EDSAC to be programmed symbolically instead of directly using machine code: the "orders" referred to were what would now be referred to as an "instruction set". After the library system was published in Wilkes, Wheeler and Gill the use of higher level instructions became universal, (and indirectly led to greater machine incompatibility!). The system was essentially designed by Wheeler, who create not only the first library system in it, but also the first Jump statement (to make it possible) (and therefore the goto!) Wilkes systematised the orders to the regional assembly, and that led to most modern symbolic assemblers, so in fact the IO was the beginning of two importantant programming traditions. Wilkes, Wheeler and Gill was the first ever programming book. People: Related languages
References: in Summer School Report Nature vol 166 view details in Applied Science Research Bulletin vol 1 (1950). view details in MTAC vol 4 (1950) view details in Journal Roy. Soc. of Arts vol 100 (1951) view details in Spectator No. 6424 vol 117 (10 Aug 1951) view details in Spectator No. 6424 vol 117 (10 Aug 1951) view details in Proc. ACM Toronto Meeting 1952 view details in [JCC 01] Joint AIEE-IRE Computer Conference Proceedings February 1952 view details in Mathematical Tables and Other Aids to Computation 7 view details in Mathematical Tables and Other Aids to Computation 7 view details in Bowden B.V. (ed.) "Faster Than Thought: A Symposium on Digital Computing Machines" Pitman 1953 view details in Report of the Conference on `Les Machines a Calcules et la Pensee Humaine.' CNRS, Paris (1953). view details in Automatic Digital Computation NPL Symposium 1953, . London, HMSO (1954). view details in IRE Convention Record Part 7 (1953) view details in IRE Convention Record Part 7 (1953) view details in IRE Convention Record Part 7 (1953) view details in IRE Convention Record Part 7 (1953) view details in Annals of the History of Computing 02(1) view details in Proceedings of the ACM conference on History of Scientific and Numeric Computation Princeton NJ 1987 view details in Annals of the History of Computing October-December 1992 14(4) view details in Annals of the History of Computing October-December 1992 14(4) view details Wheeler's paper describes the first and second forms of EDSAC's initial orders, along with the use of subroutines. EDSAC's order code and first and second forms of initial orders are listed in appendices at the end of the paper. EDSAC's programming system was largely developed by Wheeler; it was based upon a library of subroutines which could be linked together at load time. Wheeler also invented the subroutine jump ("Wheeler jump"), which, by storing the address of where program execution was taking place, enabled the machine to jump to a subroutine, execute the subroutine code, and then return to where it had left off executing the main program. These innovations provided a model for future programming development. in Annals of the History of Computing October-December 1992 14(4) view details |