tag:blogger.com,1999:blog-278187572012-01-27T20:45:11.654-08:00Anecdotes from my experiences with computers and the people who worked with them, starting in 1959. Accurate to the best of my memory, but I cannot document all of it.Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.comBlogger391100tag:blogger.com,1999:blog-27818757.post-26316503214344191002009-10-05T12:20:00.000-07:002009-10-05T12:47:32.280-07:00

I never programmed the IBM 1401, although I used mainframes that used a 1401 to do their input and output spooling. An article by John Murrell in the San Jose Mercury News notes that today is the 50th anniversary of the 1401. Among its characteristics, the 1401:Occupied a large, air-conditioned room,Weighed two to four tons (depending on configuration),Had a CPU clock speed of .000087 GHz (87

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com1tag:blogger.com,1999:blog-27818757.post-46473686006443536882008-04-09T12:53:00.000-07:002008-04-09T14:36:09.496-07:00

There is a controversial, but widely accepted, belief that on Nov. 14, 1940 Winston Churchill decided not to have the RAF defend Coventry against a major German bombing raid (500 bombers), despite having been informed of the target by Ultra (decrypted Enigma messages), in order to avoid alerting the Germans to the fact that their code was broken.The Bletchley Park Trust says that this was not so.

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-11293554534580452622008-02-19T15:46:00.000-08:002008-02-19T15:55:08.068-08:00

Here is a wiki for describing obsolete skills. Perhaps you have a few to add, yourself?Of the 97 items on the list right now, I find 60 skills that I have had. And a few missing that I'll probably add.

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-28770249197973197642008-01-30T14:30:00.001-08:002008-01-30T14:49:41.297-08:00

The winner of a contest to break a new message in a German cipher from World War II used a laptop PC and special software to compete with a reconstructed WW II Colossus electronic computer. Colossus, the size of a bus and widely recognised as being one of the first recognisably modern computers, took three hours and fifteen minutes to unravel the code.Mr Schueth and his machine took just 46

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-10955075952561348832007-08-24T10:40:00.000-07:002007-08-24T10:59:27.843-07:00

A very interesting announcement from Severo Ornstein, author of Computing in the Middle Ages.Friends,On November 3-4 the Vintage Computer Festival (VCF - see below) will be holding its annual event, and this year after lunch on Sunday the 4th the LINC will be featured. The show will take place at the Computer History Museum in Mountain View (which doesn't sponsor the event but which provides

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com1tag:blogger.com,1999:blog-27818757.post-49128477399097540222007-06-13T16:48:00.000-07:002007-06-13T16:50:54.156-07:00

Here is an interesting tale from someone else.

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com4tag:blogger.com,1999:blog-27818757.post-18281686692604248932007-05-27T20:15:00.000-07:002007-05-27T20:13:49.681-07:00

In a 1972 review in Computing Reviews, Z. G. Vranesic said flatly that no computer would give a Chess Master an interesting game in the 20th Century. I was surprised that he would bet against technology over such a long time scale--28 years.Zvonko was a friend and colleague, and I had a great deal of respect for him. He was an excellent chess player (an International Master and player for Canada

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-84361349044325458642007-05-26T23:00:00.000-07:002007-06-13T15:07:23.014-07:00

1977 Turing Award winner John Backus died on March 17.Long before I met him, he made two contributions that had major effects on my career--as well as on the field of computing: FORTRAN and BNF.John's team invented and implemented the original FORTRAN for the IBM 704 computer in the period 1954-57. In late 1953, Backus wrote a memo to his boss that outlined the design of a programming language

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com1tag:blogger.com,1999:blog-27818757.post-69540561922045714552007-04-24T18:15:00.000-07:002007-04-24T18:26:05.799-07:00

Tom Van Vleck has a choice selection posted on Multicians.Titles, just to entice you:How I got started in computers .. in a suburban basement in the 1950s1401s I have known. Includes HELLO WORLDThe IBM 7070. An interesting and little-known machineThe IBM 7094 and CTSS. MIT's two 7094sThe IBM 360/67 and CP/CMS. My experiences with the ancestor of VM/370The History of Electronic Mail. Early

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-20216128134151301642006-12-28T12:14:00.000-08:002006-12-28T12:18:19.122-08:00

No, not reincarnation. Dick Swenson is a former colleague at the University of Toronto, and has some interesting tales of his own.

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-29008182607739148482006-12-18T15:36:00.001-08:002007-06-28T17:02:22.346-07:00

Although I was not around then, I have often been told and have read that, prior to some time (generally in the 1940s), the word "computer" was understood to refer to a person, not a machine. Here are a few typical examples:"Computers were people using desk calculators when Los Alamos began.""In those days [1948], computers were people.""It begins at a time when computers were people, when women

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1161036003144415922006-10-16T14:43:00.000-07:002006-10-17T21:52:08.183-07:00

My first PL/I program [1] was a few dozen lines transliterated from Algol. I compiled it using IBM's PL/I F compiler for the IBM System/360. The PL/I F compiler was a wondrous beast. To borrow Brian Randell's phrase, it was "a triumph of engineering over design." PL/I was one of the largest and most complex programming languages of its time--perhaps of all time--intended to replace FORTRAN, COBOL

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com1tag:blogger.com,1999:blog-27818757.post-1160784711258493192006-10-13T16:48:00.000-07:002006-10-14T15:05:57.756-07:00

Bendix G-15 programmers were often obsessed with space: squeezing a little more functionality into a fixed amount of memory [example], or trimming the amount of memory required for fixed functionality[example]. (I suppose that programmers today who have only 8 KB to work with--for watches, pocket calculators, washing machines, etc.--are similarly obsessed.) This obsession was particularly

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1160686741790376582006-10-12T13:45:00.000-07:002006-10-12T13:59:01.806-07:00

I first heard this story from Kelly Gotlieb more than 30 years ago, [1] but I have retold it so often that it has come to seem like one of my own.The president of the University of Toronto received a letter from an alumna complaining that she had noticed a display of "University of Toronto Horoscopes" at Eaton's Department Store. She enclosed as evidence a sample that she had purchased. It was a

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1160359312579791832006-10-08T18:37:00.000-07:002006-11-14T11:09:01.630-08:00

In 1962, during my second summer internship at Bendix Computer Division, in addition to my regular assignment [1], I was given the opportunity to spend my spare cycles writing a Bendix G-20 program for something that interested my boss. [2] Since I didn't work with it for long, my memories of the G-20 are less vivid than for some other computers. [3] Mainly what I remember are some of the

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com2tag:blogger.com,1999:blog-27818757.post-1160353006113561072006-10-08T17:03:00.000-07:002006-11-11T15:33:16.790-08:00

A couple of error messages from 40 years ago have stuck firmly in my memory. The first is one that I actually received from the IBM PL/I F compiler: ERROR, THE PRECEDING ERROR MESSAGE CONTAINS AN ERROR. PLEASE SUBMIT AN APAR TO YOUR IBM REPRESENTATIVE.The message was absolutely correct: There was an error in the previous message. (An APAR was an Authorized Program Analysis Report.)The second is

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com2tag:blogger.com,1999:blog-27818757.post-1160098534277735202006-10-05T18:19:00.000-07:002006-10-06T09:49:18.096-07:00

The largest bill for computer time that I ever received was for a negative amount.In 1967, the Stanford Computer Center installed an IBM System 360/67 mainframe. Because government contracts required that services charged to sponsored research projects be at the lowest rate charged to anybody, student research assistants had accounts billed at the same rate (although the department or the center

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com1tag:blogger.com,1999:blog-27818757.post-1158026548472216992006-09-11T18:41:00.000-07:002006-12-03T16:47:24.330-08:00

The most exhaustively-tested program that I know of still had a serious bug when it was released. But this story has a happy ending.Background: One night circa 1960 a group of Pacific Union College undergraduate students was playing the UCLA Executive Game in the Data Processing Laboratory, when a member of one of the teams spotted an anomaly on his team's balance sheet. The numbers didn't add up

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com6tag:blogger.com,1999:blog-27818757.post-1158025059656161092006-09-11T17:06:00.000-07:002008-02-28T16:50:14.100-08:00

On a machine with binary arithmetic, conversion of numbers from decimal form to binary is easy; conversely, on a machine with decimal arithmetic, it is conversion to decimal that is easy. The Bendix G-15 had binary arithmetic internally, but most input and output was done in decimal. [1] The Bendix Computer Division [2] provided standard subroutines for single- or double-precision (7 or 14 digits

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1157940982951148752006-09-10T18:25:00.000-07:002006-09-11T10:53:06.346-07:00

One of the early applications of computer simulation to business education was an "Executive Game" developed at UCLA. Multiple teams of "executives" would make financial decisions for imaginary firms competing in the business of manufacturing and selling widgets. [1] At the start of the game, each team was given an (identical) profit and loss sheet and balance sheet from the previous quarter for

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com2tag:blogger.com,1999:blog-27818757.post-1157332031145082612006-09-03T16:41:00.000-07:002006-09-15T10:21:35.600-07:00

In 1965 Stanford University formed the first Computer Science Department west of the Mississippi, chaired by Prof. George Forsythe. [1]I applied for admission in the spring of 1966. To make sure that I was more than just a name on paper when my application was considered, I decided to visit Stanford and talk to some of the professors. A friend helped me set up some interviews. I remember only one

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com2tag:blogger.com,1999:blog-27818757.post-1157077866486971892006-08-31T17:27:00.000-07:002006-09-20T08:54:21.680-07:00

The shortest program I ever expended significant intellectual energy on occupied 116 bits on the Bendix G-15. It was a variant of the "four-word memory clear" routine. [1]Background: Around 1960, programmers still took bugs rather personally. If you were running a program (for other than debugging purposes) and the machine crashed or started misbehaving, you didn't just reboot it, you stopped

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com3tag:blogger.com,1999:blog-27818757.post-1156905238898954292006-08-29T19:23:00.000-07:002006-09-24T18:05:17.943-07:00

[Skip this post if you're interested only in my stories.It is expository, rather than anecdotal, part of my discussion of the Bendix G-15 architecture, which will feature in some of my stories. It relies on material from the Bit-serial arithmetic and G-15 Memory Model posts. [1]]"Computers were expensive,programmers were cheap." [2]The basic structure of the G-15 involved 28 drum lines. In normal

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1156894648628033102006-08-29T14:53:00.000-07:002006-09-04T17:57:52.466-07:00

[This is part of a series of expository, rather than anecdotal, notes, but it provides background for my discussion of the Bendix G-15 architecture. Skip it if you're interested only in my stories.]As far as the programmer was concerned, the G-15's memory of 2,183 (29-bit) words [1] was organized into20 "long lines" numbered from 0 to 19, each containing 108 words.4 "short lines" numbered from 20

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1156551578084066282006-08-25T17:06:00.000-07:002006-08-25T17:19:38.110-07:00

Don’t worry about people stealing your ideas. If your ideas are any good, you’ll have to ram them down people’s throats.-- Howard AikenReported by me as heard from his student Ken Iverson at the History of Programming Languages conference in 1978.

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1156386311915290042006-08-23T18:23:00.000-07:002006-09-14T12:17:18.526-07:00

Yes, there were hard disks for computers even before I started using them. Yesterday's Wall Street Journal had a story by Lee Gomes on the 50th anniversary of the hard-disk drive. Worth reading in full, but here are some excerpts: [The hard drive] is the storage device that makes possible not only PCs, but also iPods, TiVos and other consumer technology must-haves.The first disk drive, called the

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1154401121716833472006-07-31T19:00:00.000-07:002006-07-31T20:43:15.143-07:00

Prior to IBM's 1964 introduction of the System/360 family of computers [1], computer memories were generally measured and addressed using the same units in which they were accessed: words (of 8, 12, 16, 24, 29, 32, 48, or 60 bits, depending on the computer), characters (generally represented by 6 or 7 bits), or digits (BCD, represented by 4 bits).All System/360 computers executed the same

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1154145120663189392006-07-28T20:38:00.000-07:002006-08-29T18:29:18.483-07:00

In the summer of 1961 I attended a lecture in Los Angeles by a little-known Danish computer scientist. His name was Peter Naur [1], and his topic was the new algorithmic language Algol 60. He covered a lot of concepts that I hadn't picked up from my limited study of Algo, though of course I didn't really absorb very much of them from one lecture.But I do remember one thing clearly:At the end

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1153117745644634042006-07-16T22:24:00.000-07:002006-12-10T19:36:16.810-08:00

[This is part of a series of expository, rather than anecdotal, notes, but it provides background for my discussion of the Bendix G-15 architecture. Skip it if you're interested only in my stories.]With the "embarrassing parallelism" of today's microcircuits, where the challenge is to keep many of the millions of available transistors busy at the same time, it is easy to forget just how little

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1152054247640440882006-07-04T15:09:00.000-07:002006-09-03T22:23:41.843-07:00

Bendix Computer Division produced one of the first implementations of a language in the Algol family. The Algo system for the G-15 was based on Algol 58. It was a three-pass compiler [1] that produced code for a virtual machine rather similar to Intercom 1000.Due to memory limitations, intermediate data between passes of the Algo compiler had to be punched out on paper tape and then read back

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1151362026511803442006-06-26T15:34:00.000-07:002006-06-26T15:59:26.546-07:00

Alan J. Perlis was not only a wonderful human being, an excellent mentor to many computer scientists, and a talented coiner of aphorisms, he was also a great storyteller. I remember one of his stories concerned computer architecture. I may not have remembered all the details exactly, but here is the gist:When we were preparing to take delivery of the Bendix G-20 computer at Carnegie [1] a man

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com1tag:blogger.com,1999:blog-27818757.post-1150765739770647542006-06-19T16:31:00.000-07:002006-10-11T17:39:09.676-07:00

The Bendix G-15D represented an architectural dead end. Only a few later commercial computers, such as the Packard Bell PB 250, followed the same lines, and none of them were as successful as the first-generation G-15 and LGP-30. Even Bendix went to an architecture much closer to Intercom than to the G-15 for their transistorized computer, the G-20 (which also cost 10 times as much).So the G-15

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1148860182190577462006-05-28T16:21:00.000-07:002006-10-28T23:59:49.613-07:00

After I wrote my first few programs for Intercom 1000, the other students frequenting the DPL made it very clear that Real Programmers wrote machine code [1, 2]. By this, they meant instructions for the hardware that ran the Intercom interpreters, the Bendix G-15D computer. [3, 4]The G-15's instruction set architecture was almost the antithesis of Intercom 1000's ISA. It was the reduced

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com7tag:blogger.com,1999:blog-27818757.post-1148602814236580072006-05-25T17:12:00.000-07:002007-05-31T18:31:32.036-07:00

On September 30, 1976, [1] I was asked to give the after-dinner speech at a workshop hosted by Cornell University to discuss the WOODENMAN version of the DoD's requirements for the language that eventually became Ada.Let Prof. John Williams [2] set the stage:Just after dinner on the first evening of the workshop, a tall gaunt and bearded man [3] rose quietly and moved toward the front of the hall

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One evening in the summer of 1959 (probably during July), I was hanging around PUC's DPL soaking up the ambiance and the reflected glory of the programmers.An older student, who was running an Intercom 1000 program, exclaimed, "This is the slowest-converging series I've ever seen!" He was printing every tenth partial sum, and after more than sixty printouts (600 terms), the sums were still

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1147648048557878532006-05-14T14:44:00.000-07:002006-09-12T17:45:01.420-07:00

In 1959 there cannot have been very many places in the world where a 16-year-old entering freshman was given free access to an electronic digital computer. Among small liberal arts colleges, Pacific Union College may have been unique in providing such access. I had the great good fortune to be there, for no better reason than that it was the alma mater of my parents.The Data Processing

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1147498425883483642006-05-12T22:32:00.000-07:002006-10-28T23:44:24.596-07:00

The first electronic digital computer that I was ever close to was also the first that I programmed and the first that I operated (summer 1959): Intercom 1000. Intercom 1000 was a virtual machine [1], like today's Java Virtual Machine, implemented by an interpreter running on the hardware of the Bendix G-15 General Purpose Digital Computer. [2]Intercom 1000 was intended as the source language in

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1147310444877122672006-05-10T17:49:00.000-07:002006-05-10T18:47:01.056-07:00

As technology and society advance, it seems to be the perennial habit of old-timers to tell young whipper-snappers that they just don't know how tough it was in the old days.I will not be able to completely avoid such remarks in this blog. In many important respects, computing technology has advanced by at least nine (decimal) orders of magnitude during the period I have been involved with it.

Jim Horninghttp://www.blogger.com/profile/01813631663553781471noreply@blogger.com0tag:blogger.com,1999:blog-27818757.post-1147199686536513652006-05-09T11:34:00.001-07:002006-12-05T11:16:31.870-08:00

Those who cannot forget the past are condemned to remember it.--Jane AceI have encountered many interesting people, machines, and software systems since I was first introduced to a computer in 1959, and have been involved in some interesting situations. I've been encouraged by friends to write some of these down.At present I have neither the time nor the ambition to organize these memories into a

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