Archive for category: Computer Science

Making some wallpaper with the sum of cosines…

November 2, 2011 | Computer Graphics | By: Mark VandeWettering

I was inspired by some Haskell code written by keegan, so I had to write a version of it in C. I didn’t do any animation, but I did have a lot of fun playing around with the parameters. For instance, check out the code, and how changing the value of N from 5, 7, […]

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Can we go beyond WSPR? An idea for beacon operations on amateur radio.

September 13, 2011 | Amateur Radio, Cryptography | By: Mark VandeWettering

I was interested in WSPR and visual MEPT oeprations for quite some time. I operated both a beacon and a QRSS aggregator on 30m for a while, but I grew a bit tired of it, and it’s been silent for a year or so. But I haven’t stopped thinking about them. In fact, I’ve had […]

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Sprites mods – CP/M on an AVR

September 5, 2011 | electronics, Hacking, Hardware | By: Mark VandeWettering

I’ve always been fascinated by emulation and virtual machines, as well as retro-computing: resurrecting the old machines of my past. I never owned an old CP/M machine, but there are still some neat projects where people construct there own, and simulators like SIMH and YAZE-AG are good software simulators. But what I always wondered was […]

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Donald Michie, Alan Turing, Martin Gardner, and Tic Tac Toe

August 28, 2011 | Computer Science, Cryptography, Games and Diversions | By: Mark VandeWettering

As anyone who reads my blog with any regularity will tell you, I like to read and learn new things. The problem with being self taught and also easily distracted means that you often learn a great deal, but don’t always perceive the connections and scope of what you are learning. I found another example […]

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Return Infinity – BareMetal OS

May 28, 2011 | Computer Science, Operating Systems | By: Mark VandeWettering

At various times, I’ve been interested in writing operating systems. I haven’t done much thinking about this recently, but it is a topic of interest. I hadn’t seen this project before: a small 64 bit kernel written in assembly. I have no idea whether it’s interesting, but I thought I’d bookmark it for future investigation. […]

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My trip down memory lane leads me back to TOPS-10 and the PDP-10

May 17, 2011 | Computer Science | By: Mark VandeWettering

I’m going to be nostalgic for a few moments. If you are too young to have any sense of nostalgia, skip ahead to the bold text below. You were warned! A few days ago, I mentioned that I was having a bit of flashback, thinking of my first experience with time sharing computers back in […]

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Magnetic core memory reborn… on an Arduino????

May 11, 2011 | Computer Science, electronics, Hacking, Hardware | By: Mark VandeWettering

I may have mentioned before, I’m kind of old. One measure of how old I am is the fact that I’ve actually programmed machines that used core memory. Real core memory. Little ferrite donuts on arrays of wires. Some time ago, I remember running across this awesome blog post from “Wayne’s Tinkering Page” which showed […]

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Word squares…

May 4, 2011 | Computer Science, My Projects, Puzzles | By: Mark VandeWettering

I like to read the Programming Praxis website. Every post challenges you to write some simple programs to boost your skill, akin to finger exercises for a musical instrument. Today’s challenge was an interesting which intrigued Charles Babbage: creating word squares. I spent about 10 minutes writing one in Python that worked rather well: here […]

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A small standalone homebrew computer: FIGnition by Libby8dev

May 1, 2011 | electronics, Hardware | By: Mark VandeWettering

I’m old. I learned to program as a teenager in the 1980s. Back then, we learned to program on small microcomputers. These machines weren’t very powerful, but they had a neat feature: they were self-hosted. In recent years, a large variety of small microcontrollers have become popular. Many of these have capabilities far in excess […]

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Watermarking and titling with ffmpeg and other open source tools…

April 19, 2011 | Amateur Radio, Computer Graphics, Games and Diversions, My Projects, Video | By: Mark VandeWettering

I’ve received two requests for information about my “video production pipeline”, such as it is. As you can tell by my videos, I am shooting with pretty ugly hardware, in a pretty ugly way, with minimal (read “no”) editing. But I did figure out a pretty nice way to add some watermarks and overlays to […]

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Code from the Past: a tiny real time raytracer from 2000

April 12, 2011 | Computer Graphics, My Projects | By: Mark VandeWettering

Back in 2000, I was intrigued by the various demos that I saw which attempted to implement real time raytracing. I wondered just what could be done with the computers I had on hand, without using any real tricks, but just a straightforward implementation of ray/sphere and ray/patch intersection. As I recall, I got two […]

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Cool Hack O’ Day: real pixel coding

April 11, 2011 | Computer Graphics, Link of the Day | By: Mark VandeWettering

The problem with working some place with lots of intelligent people is that it is increasingly hard to maintain one’s sense of superiority. Today, I tip my hat to Inigo. He has a very cool demo here, where he creates a program by creating and editing a small image in photoshop, saving it as a […]

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Neat article on William Friedman and Steganography

March 28, 2011 | Cryptography | By: Mark VandeWettering

William F. Friedman is a name that might not be familiar to you unless you are a bit of a cryptography nut. Of course, I am a bit of one: I have a couple of long technical notes that were authored by Friedman on the cracking of some complex WWI era ciphers. But I must […]

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Demo of Enigma and the Turing Bombe at Bletchley Park

March 15, 2011 | Amateur Radio, Cryptography, My Photos, My Projects | By: Mark VandeWettering

Carmen and I just got back from a trip to London, and we had a blast. One of the geekiest things we did while there was to take a day trip by train out to Bletchley Park to see the site of the codebreaking efforts by the British during WWII. As any long time reader […]

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Hershey Vector Fonts

February 28, 2011 | Computer Graphics, My Projects | By: Mark VandeWettering

Nearly thirty years ago, I remember hacking together some simple code to display graphics on a WYSE 35 terminal. The terminals supported the TEK 4014 graphics commands to draw vectors, and I found the original “Hershey Fonts”, created by A.V. Hershey at the U.S. National Bureau of Standards, and placed in the public domain. I’ve […]

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