Monday, February 29, 2016


The March issue of Communications of the ACM includes an article by Andrew S. Tanenbaum, "Lessons Learned from 30 Years of Minix", which is well worth reading for those interested in operating systems in general or the UNIX/POSIX/Linux world in particular. Tanenbaum developed Minix, a UNIX-workalike that would run on an original IBM PC (256kB RAM and a single 360kB 5.25" floppy disk), in order to have an operating system that students could study in a course or on their own. One of those, presently, was Linus Torvalds, who decided to write his open operating system, Linux, for the x86 architecture.

Operating Systems Design and Implementation, the book that Tanenbaum wrote along the way, is excellent. Sometime in those years, I took a course on operating systems, which used two books, Tanenbaum's and another. The other book would have something like "operating systems use page to move code not currently needed off to disk." Tanenbaum's would have a diagram of the memory management unit of a widely used processor, with an explanation of how it supported paging. And then there was the full source code of Minix in the back of the book. The book is by now on its third edition.

Saturday, February 20, 2016

Compatibility View

The other day, I had to change the database connection information for a reporting server. Somewhat to my surprise, the configuration programs on the server itself did not all me to change that. So I pointed Internet Explorer to the server URL, It let me log in, but when I tried to go to the administrative section of the site, I got odd Javascript errors. I tried Firefox and Chrome, which did not give me errors, but also gave me no administrative section. At that point, I remembered that Internet Explorer reverts to older behavior (Compatibility View) when the URL has no domain extension. I went into the Internet Services Manager on the server, and added the domain-less name to those that the site would serve. Then Internet Explorer logged me in automatically, I got no more Javascript errors, and was able to correct the database connection information.

I believe that it was a consultant who set up this server in the first place, and why and how he set it up IIS not to serve the domain-less name I can't guess. Probably I had never logged on through the web interface, for the menus and connection strings were unfamiliar. I wonder when corporate networks will be freed from the need for IE 7 compatibility, and what pain the change will inflict.

Thursday, February 18, 2016

Author Unknown

Last night, while looking into Boswell's The Journal of a Tour to the Hebrides, I noticed in the entry for Friday, 27th August (1773)
Mr. Grant having prayed, Dr. Johnson said, his prayer was a very good one;  but objected to his not having introduced the Lord's Prayer. He told us, that an Italian of some note in London said once to him, 'We have in our service a prayer called the Pater Noster, which is a very fine composition. I wonder who is the author of it.'--A singular instance of ignorance in a man of some literature and general inquiry.
This sounded familiar. In his memoirs, in an entry for 1707, Saint-Simon writes of the Comte de Gramont
When he was 85 and mortally ill his wife tried to speak to him of God; but the complete oblivion in which he had lived all his life made him regard the mysteries with utter incredulity, and when she had finished he said, 'But, Madame, is what you say really true?' When he heard her recite the Paternoster he said, 'I think that is a beautiful prayer, who wrote it?'
 I certainly don't doubt Johnson's word. Saint-Simon is a bit too fond of a good story, but apparently Gramont's obliviousness to religion is well attested.

(And while I'm not on the subject, why doesn't Oxford University Press bring back into print R.W. Chapman's handy volume containing both Johnson's A Journey to the Western Islands of Scotland and Boswell's Journey? If Chapman's work is superseded, then why not a few pages of notes?)

Saturday, February 13, 2016


I got a fair way into middle age with decent eyesight. My left eye, near-sighted since adolescence, served for reading, and my right eye, close to 20/20 for much of my life, took over past arm's length. I complied with the terms of my driver's license by wearing glasses when I drove, but I didn't really need them.

Somewhere after 50, that didn't work. I started to buy reading glasses at the local drug stores. A couple of years ago, I should have understood that this wasn't getting the job done, and that the rapid changes between distance and reading glasses were just too inconvenient. But I was stubborn, and did many quick changes.

This time, I opted for "progressives", not classic bifocals with a sharp line between distance and reading prescriptions, but  with a gradual transition. The staff at the glasses store spoke well of them, though now I wonder whether their enthusiasm was for the excellence of the lenses or the size of the bill. Having tried them now for almost a week, I still don't know.

It seems to me that nothing is wholly out of focus, and little is quite in focus. At best, there seems to be a cone of good focus with an angle of 30 degrees. In reading, it is OK for about four fifths of the width of a page. It feels at times as though I were using a fish bowl to read the newspaper through. For distance, I find myself  having to tilt my head to focus well on the faces of those not much taller or shorter. But the blurred peripheral vision near the top may be the most annoying part.

My wife says that I shouldn't drive with such glasses until I've had them for six months. I don't doubt her at all.

Saturday, February 6, 2016

Support Days, I

About thirty years ago, I started to work in customer support at a company that made typesetting systems. The software ran on minicomputers, which were "mini" in comparison to the mainframes of the day, water-cooled machines that required raised-floor rooms. A minicomputer was simply the size of a refrigerator, say six feet high by two wide and two deep. These minis came from Data General, long since gone, and mostly were 16-bit machines running RDOS (real-time disk operating system) or 32-bit machines running AOS/VS (the advanced operating system with virtual storage).

At some point it must have occurred to someone at Data General that people wanted and were buying smaller computers. Data General therefore produced a small machine, the name of which escapes me. It was about the size of a toaster oven: remove the handle of a toaster over, spray paint it Army green, put on a couple of serial ports, and you will have something that looked like this machine. It had about 40 MB of disk space, roughly one five thousandth of the storage on the iPhone 5 in my pocket.. Our company had heard of desktop publishing, and must have decided to see whether people really wanted a Macintosh with Display Postscript and WYSIWYG, or would prefer a toaster oven with green screen dumb terminals and a hyphenation and justification pass.

The toaster oven was not popular. That I heard, only two of these machines ever shipped. One went to our West Coast support rep. One went to a small company in this area. One day, I was sent to the local company to see what I could do for them. The owner's complaint was lack of disk space. I was not familiar with the machine, nor with its operating system (AOS, a 16-bit predecessor of AOS/VS). But after some poking around I found a directory tree of unused software, removed it, and got back the space he wanted. Sometime during the course of the visit, having noticed my unfamiliarity, the owner asked, "How many of these things are out there?" I said something like "Well, not an awful lot."

Data General is, as I say, gone. It tried to make the transition to selling computers running a UNIX variant on RISC chips, and by all accounts made a pretty good machine. But even the companies who got into that business without the old minis to support are mostly gone now. I have heard, within the last ten years, of somebody running my old company's software, on what platform and how supported I can't guess. The guy with the toaster oven wasn't doing much of anything Word Perfect 4.2 wouldn't do, and I don't suppose his business survived very long.

Friday, February 5, 2016


About forty years ago, I watched an hour of "Firing Line" in which Leslie Fiedler was the guest. He spent most of fifty minutes explaining to William F. Buckley, Jr., that he considered the distinction between popular and high literature to be false and misleading, and why he thought this. I'm not sure now whether I agreed with him at the time. But I thought that he had made his position entirely clear. Fiedler wrote and spoke well, and Buckley's questioning gave him full scope to clarify anything one might have misunderstood.

On "Firing Line" there was always a panel that got to ask questions in the last ten minutes of the hour. The panel this time was made up of professors of literature from a local university or local universities. The first question any of them asked was, "Well, then Professor Fiedler, how would you distinguish high from popular literature?" At the time, I was astonished, for I had not yet learned the extent to which adults will not listen to one another. I am still surprised, since these men were put in front row seats for the purpose of listening to the conversation in front of them, and responding to it.

On reflection, I think that one can distinguish the purposes for which works of literature are written: the market, self-expression, forging the uncreated conscience, etc. However, it is drearily clear that much literature created with the best of motives is immediately or soon unreadable. And much literature that once qualified as popular literature--Homer, Dickens, one could say Tolstoy--remains worth reading and re-reading.