The Guiness Book of Computer Records by Lynn Yarbrough It would be interesting to add a chapter to the Guiness Book of World Records on the topic of computer programs. What is the biggest computer program ever written? The longest running? The most complex? The most famous? The most used? In order to establish records for these and other categories, we must first agree on what we mean by some of these. For example, we probably can agree on a criterion for complexity: the total number of conditional jumps is an obvious one. But to eliminate programs constructed solely for the purpose of breaking records, we would also have to establish some criterion for usefulness - and that may be difficult to get people to agree on. Here are some candidates for records, based mostly on my own limited knowledge and personal criteria for usefulness. I am eliminating operating systems from consideration, because they are intended to run forever, or at least until the computer conks out, and concentrating on programs that are designed to solve specific problems. Biggest program - The Project Apollo real-time system. I don't know quite how big it is, but it's on the order of 1,000,000 lines of code. Most complex - Maybe Project Apollo again, but for density of conditions I suggest that PL/I compiler may have a higher percentage of conditional jumps. Any other candidates? [image] Most famous - The COBOL compiler on the IBM S/360. Most used - The control programs for the Bell Telephone Companies' Electronic Switching System. Most subroutines - I had heard, a few years ago, of a FORTRAN program with just under 200 subroutines, but I can't claim a record for that because I can't identify it. Has anyone a candidate for this category? Longest running - Prof. Donald Knuth of Stanford University once ran a program to exhaustively analyze a chessboard problem. The program was run at odd hours when the computer was otherwise idle, and thus took over a month to complete. In total, the run used about 180 hours of central processor time - on a CDC 6600! But the Atomic Energy Commission people may have this record beaten already - can anyone fill us in? [image] If instead of only programming records, we extend our new chapter to include other computer-related records, here are some other items for consideration. The largest punched card file in the world was for many years maintained by the U. S. Bureau of the Census. After the census of 1960 this file contained over 500,000,000 cards. Consider the amount of storage space for this amount of cards; packed as densely as possible this represents a stack of cards over 100 miles long! (I wonder if this file is still maintained, and if so how big it got after the 1970 census.) The largest magnetic tape file in the world is maintained by NASA. It consists of all the telemetry and other data gathered from all the missions, both successful and otherwise, flown by U. S. rockets and satellites since the beginning of the space program. (NASA has a major problem in using this data before the tapes disintegrate. There is so much data that 90% of it will probably never be examined by anyone.) What facts can you add to the CREATIVE COMPUTING book of programming or computer records? Who can tell us more about the widest magnetic tape (3" tape used by an early Honeywell computer), or the amount of heat generated by Einac or Whirlwind, or the most computers tied together (ARPA Net?). As you give us information, we'll try to tie it together and publish the results from time to time.