Solipsism Gradient

Rainer Brockerhoff’s blog

Browsing Posts published in June, 2003

Posted by Rafael Fischmann:
Have a wonderful trip, Rainer! And don’t forget to send news through the weblog as soon as you can — you can leave, however, the pictures part for the time when you come back, otherwire you’ll get mad.

Posted by Buzz Andersen:
Lucky devil–have a great time! I did a similar tour to what you’re planning a few years ago and had a great time. Berlin in particular is a really cool place to see–especially for a history buff like myself. I look forward to seeing your pictures…

We’re off…

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The Europe trip begins in a few hours. Everything’s packed, I’ve collected a number of old and new photos to show to our relatives, and I’m loading them into the Pentax as I’m writing this.

It took some time to figure out. The camera’s SD card contains a main folder called “DCIM”, inside that there are folders called “nnnPENTX” (where nnn is a 3-digit number from 100 to 999 – I didn’t try smaller numbers). Inside each folder there may be .jpg, .avi or .wav files whose name must be “IMGPnnnn.xyz”, where nnnn is any 4-digit number and xyz the proper extension. The card is formatted in MSDOS format. JPG files can be saved as “optimized” to be played back by the camera, but “progressive” isn’t supported – oddly enough, the Finder’s preview function fails for these files! Some larger images also gave an error, so I scaled them down. I didn’t try to test compatibility for the .wav and .avi files. Files which don’t obey these conventions seem to be ignored, although once I managed to lock the camera with a “card error” message… reformatting took care of that.

We’ll leave for the airport at 16:00 local (16:00 UTC) – it’s 45km away. The plane takes off at 19:08 to São Paulo, then at 22:35 we’ll fly KLM to Amsterdam, where we’ll arrive at 14:50 local (12:50 UTC). Then the final connection to Frankfurt will leave at 17:55 and arrive at 19:10 local (17:10 UTC). My cousin Jürgen, who coincidentally works at Frankfurt Airport, will pick us up and take us to nearby Ingelheim, where we should arrive around 20:00 local (18:00). This means 26 hours from door to door icon_eek.gif!

Remarkably few of my relatives seem to have e-mail; on my last trip in 1995 very few had even heard of the Internet. Anyway, I’ll try to locate an Internet Café every few days to post updates here.Posting photos will probably be impossible until our return on July 3rd.

Posted by coredump:
If you write a Biography I’ll be the first to buy it 😉

And the things are so much fun in the mainframe times… icon_neutral.gif , wish I was living in this times. or in the 50’s, in the New Orleans area… icon_razz.gif

Newly Digital

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Adam Kalsey is asking people to write about their early computing experiences, so of course I’ll have to goof off and write about mine instead of packing for our Europe trip icon_wink.gif. I was thinking of starting a series of notes for future biographers, anyway…

Sometime in 1967, while browsing at a local library I stumbled upon Elliott Organick‘s “A FORTRAN Primer”, and immediately realized this was hot. I promptly bought Organick’s more up-to-date “FORTRAN IV” and proceeded to learn it forward, backward and sideways. As I had no computer available, I typed my programs on long rolls of paper on an old Olivetti Linea typewriter and tried to single-step and debug them by hand. I remember doing factorials with many digits and other number puzzles from Martin Gardner‘s column in Scientific American.

The next year I casually mentioned the matter to my math teacher, who immediately sent me to the local university’s Engineering School, where they had a IBM 1130 mainframe. This was housed in a large air-conditioned room. The IBM 1131 CPU used magnetic core memory: 8K words of 16 bits each (later expanded to 16KW). The clock frequency was 280 KHz. The CPU also housed a 500KW magnetic cartridge drive and a keyboard with a Selectric-type “golf ball” printer. Other peripherals were the IBM 1442 card read-punch, the IBM 1132 line printer, a pair of paper tape read/punch units, and my personal favorite, the IBM 1627 plotter.

I immediately enrolled in keypunch and FORTRAN classes (with a special dispensation as I wasn’t a student), and began to pester the local staff to cadge computing time. After first getting the factorial calculator to run, I started to write a program for the plotter, inspired by yet another Scientific American article; over several months it evolved into a complex kludge, drawing an arbitrary number of (possibly intersecting) ellipsoids in 3D space from any vantage point, with hidden-line removal. Being unaware of existing hidden-line removal algorithms I tried to solve it by trigonometry, which worked but became extremely slow for the more interesting cases.

The next year I entered the school officially as an Electrical Engineering student, and promptly became attracted by a free systems analysis course to be offered by IBM. This was a 2-hours per day, every weekday, 9-month course sponsored by the university; 20 students were selected from over 200 applicants, and I placed second. The course was excellent, and the two best students were offered an internship at the university’s main computing center, so I made sure to place first…

CECOM, the computing center, at the time had an even older mainframe: the IBM 1401. The CPU had 4000 bytes of core memory; each byte had 6 BCD data bits, a parity bit, and a “word mark” bit to flag the end of a variable-length field; clock frequency was about 83 KHz. The only peripherals were a card read-punch and a line printer, and programming was in Autocoder (assembly) or machine language. It was already obsolete and soon was replaced by a IBM/360-40, itself replaced a few years later by a Burroughs B6700, which remained in use for 13 years. Amazingly, I can’t locate any photo or reference manual of this machine.

The B6700 was huge. The CPU had 800K of semiconductor (static) memory, which was state-of-the-art at the time and had a 800ns access time, if I recall correctly. It also had a 10MB fixed disk drive for virtual memory and operating system bootstrap; this had one magnetic head per track with several huge platters revolving on a horizontal axis. There were half a dozen magnetic tape units, removable disk packs (100MB each), and several fast line printers and card readers; later on about a dozen video terminals were installed. The B6700 had a very interesting architecture, with 51-bit words: 48 data bits which could be interpreted as 6 characters, as well as 3 tag bits which defined the word format. There were different formats for instruction words, address pointers for integers and floats, strings, and stack pointers. The machine was stack-oriented and and had no assembly language; the MCP operating system was written in an Algol dialect called ESPOL. As we had full source code for the MCP and for the compilers, I had a merry time – for several years, it turned out – hacking around and learning about operating system and compiler design.

In 1977 I acquired an Apple II and left the mainframe world. More in the next chapter…

Re: Geek Test

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Posted by Mau:
I have just gone through it…

I AM A GEEK GOD!

65.68047% – Geek God

Não sei se isso é bom ou ruim… javascript:emoticon(‘icon_cool.gif‘)

Boa viagem, Rainer, e divirta-se com a câmera… Saudações floridianas!

Just a few updates. LetsGoDigital has some very nice pictures of the camera.

Taking pictures at the party yesterday mostly worked fine. I did confuse the power button with the shutter button twice, and sometimes the flash-precharge time seemed overly long; also, the LCD display blanks out for a second while the flash fires. One image was very blurry – I think inadvertently turned the flash off, so the camera shifted to a longer exposure time. The rest were mostly fine, if not too sharp, and a little darker than I normally like. I tried out the movie clip feature but the room was too dark for that. I took some pictures under incandescent lights but the auto white balance didn’t work too well.

Afterwards, downloading the pictures to our host’s Windows XP laptop worked fine with no additional installation. Coincidentally, he’d just gotten a Olympus C-4000; it was striking to compare them side-by-side, the Olympus looks big and clunky. At maximum resolution, the Olympus takes a 2288×1712-pixel picture compared to the Optio’s 2048×1536. Other features are roughly equivalent, but the Olympus weighs 400g compared to the Optio’s 115g!

Reading the manual I discovered other goodies. The movie clip mode takes a maximum of about 370 frames (30 secs at 12.33 fps). However, one can divide the frame rate by 2, 5, 10, 20, 50 or 100 to make time-lapse movies; at the last rate, this means 50 minutes are compressed into 30 seconds. This should be fun; I’ll have to find my old pocket tripod for testing this. Images can be cropped to a smaller size inside the camera, copied between the internal memory and the SD card, and b&w, sepia, and colored filters can be applied.

As soon as possible, I plan to buy a spare battery, the AC adapter and a case for the camera; none of these were available at the store when I ordered it, unfortunately.

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