From: "John W. Kennedy" Date: 2007-07-21T02:05:03+09:00 Subject: Re: Taking the bull by its horns [was background] Morton Goldberg wrote: > On Jul 19, 2007, at 9:00 PM, John W. Kennedy wrote: > >> Never had a 650 to work on, but read the manual once, a long, long, >> long time ago. My first programs were written for the 7070, which was >> the follow-on to the 650, but, since it used core, had a conventional >> instruction counter instead of a next-instruction-address field. > > I wouldn't characterize any 70X/70X0 machine as a follow-on to the 650. > They were a mainframe series derived from the Whirlwind project, an IBM > military contract. The R&D tab for the 70Xs was picked-up by the US > taxpayer. The 70Xs were vacuum tube machines and were introduced at the > same time as the 650 -- the 70X0s were the later transistorized > versions. A) There were a number of completely different 70x/70x0 lines, and, B) the Whirlwind was done by MIT; I cannot at this moment find any evidence that IBM was involved at all, although IBM later used parts of the abandoned Whirlwind II specs for the noncommercial AN/FSQ-7. Development of the 701 was certainly stimulated by the Korean War, but it and its successors were never intended specifically for government use. > I don't remember a 707, but if there was a 7070, I would > expect a 707 existed as a predecessor. I did some Fortran programming on > a 709 and a 7040. That's simply wrong. There was no 707, and the 7070 /was/ the follow-on to the 650, as any history of IBM's pre-360 computers will tell you. As with the 701->704, 702->705, and 1401->1410 transitions, the machines were not compatible, but general concepts and formats were. In this case, the 7070 retained the basic 650 word architecture of ten decimal digits plus a sign, and continued to use two-digit op-codes and four-digit addresses. But the four digits that the 650 used for the next-instruction address were replaced by two digits to select an index register and two digits to select a subfield of the data word. > AFAIK, the 650 was developed as a business machine with IBM's own funds > by an entirely different engineering group than the Whirlwind group. > There is nothing in common between the two architectures. The 650 not > only used dual-address instructions, it wasn't even a binary machine. It > was a dead-end architecture. No, the 7070, 7072, and 7074 were follow-ons to it. The IBM pre-360 commercial lines (-> incompatible; => compatible): The main scientific line 701->704=>709=>7090=>7094=>7094 II | .->7040=>7044 (The 7040 line was a cheaper subset of the 7090 line. It did /not/ derive directly from the 704, as some have incorrectly concluded from the number.) The famous STRETCH supercomputer. Not truly a failure, but IBM lost money on it when they gave refunds because it wasn't as good as promised. Still, a lot of STRETCH concepts, reworked, went into the 360. 7030 Budget scientific and real-time. 1620=>1710 (The 1710 was a 1620 with command-and-control extras. There was also a one-off 1720.) The main business line. 702->705=>705 II=>705 III=>7080 Cheaper business machines (and upward extensions). 1401=>1460 | | | .->1440 | .->1410=>7010 (The 1440 was an almost-compatible cheaper version of the 1401; the only incompatibility was in the handling of punched cards and printing. The 1410 was an incompatible upward extension of the line; machine code was different, but carefully written assembler code could be portable. Two more systems in the line were the 1240 and the 1420, which were essentially 1401s with magnetic-ink reader/sorters in the same chassis.) The first machine with a disk for business. Existing systems with added disks were more successful. 350 Budget general-purpose machines. 650->7070=>7072=>7074 Almost a PC. Too little and too late to get much of a market. 610 -- John W. Kennedy If Bill Gates believes in "intelligent design", why can't he apply it to Windows?