computers of IAS machine design had no index register. Using self-modifying code was necessary for array operations. The LGP-30 instruction did "replace the contents of the address portion of the word in memory location 2000 with the contents of the address portion of the word in the accumulator" to ease writing self-modifying code. History The essay was originally published in the Usenet news group "net.followup" on May 21, 1983, by utastro!nather (the UUCP email address of Ed Nather at the time). The Royal McBee computers were developed and manufactured by Librascope, and the documentation written for the blackjack program was written by Mel Kaye of Librascope Inc. The August 1956 edition of The Librazette, the Librascope newsletter, contains a story about training on the LGP-30, and mentions that some Librascope application engineers were transferred to the Royal McBee payroll. Among the engineers named is Mel Kaye. There is a photograph on the front page of that issue showing that first class of neophyte LGP-30 programmers and the instructors, including Mel Kaye. See also Real Programmers Don't Use Pascal References Further reading (NB. A copy of the original prose version.) (A completely original copy of Ed Nather's Usenet post, with headers) (NB. Punctuation added/corrected for readability. Contains link to program tape of blackjack for LGP-30) (Mel Kaye's signature] on a coding sheet for the LGP-30.) (NB. Presumably the subject of the original story.) (NB. Detailed analysis of the story, explaining the technical details.) Contains even more technical details (A research on the origins of the story, its characters, Mel Kaye's biography, and hacker folklore in general) A redditor found a computer of the type that Mel used in his grandparents basement. Computer programming folklore 1983 essays