Mandelbrot on a vintage IBM1401

Gepostet vor 11 Monaten, 29 Tagen in #Misc #Tech #Coding #Fractals #Hardware #Mathematics #Retrotech

Share: Twitter Facebook Mail

mand1

Ken Shirriff hat im Computer History Museum in San Francisco einen ollen, aber funktionierenden IBM1401-Rechner gefunden. Also hat er dafür ein Mandelbrot-Apfelmännchen in Assembler programmiert, das Programm auf ebenso olle Lochkarten gestanzt, das Teil einmal durchrattern lassen – „The cards fly through the reader at the remarkable speed of 800 cards per minute so the Mandelbrot program loads in just over a second“ – und das ganze schließlich auf ’nem Zeilendrucker ausgegeben. Nice! (via Visualizing Math)

mand2

The program fits onto just 16 cards, but the card format is a bit unusual. The machine code for the Mandelbrot program is punched into the left half of the each card, with code such as M384417A395417. An interesting thing about the 1401 is the machine code is almost human-readable. M384417 means Move field from address 384 to address 417. A395417 means Add the number at address 395 to the number at address 417. The text on these cards is the actual machine code that gets executed, not the assembly code. Since the machine is character-based, not binary, there's no difference between the characters "428" and the address 428.

If you look at the right half of the cards, there's something totally different going on, with text like L033540,515522,5259534. There's no operating system, so, incredibly, each card has code to copy its contents into the right place in memory (L instruction), add the word marks (, instruction), and load the next card. In other words, the right hand side of each card is a program that runs card-by-card to load into memory the program on the left hand side of the card deck, which is executed after the last card is loaded.

To run the program, first you hit the "Power On" button on the IBM 1401 console. Relays clunk for a moment to power up the system and then the computer is ready to go (unlike modern computers that take so long to boot). You put the cards into the card reader and hit the "Load" button. The cards fly through the reader at the remarkable speed of 800 cards per minute so the Mandelbrot program loads in just over a second. The console starts flickering as the program runs, and every few seconds the line printer hammers out another line of the fractal. After 12 minutes of execution, the fractal is done.

mand3
wolf

Algorithm watching Wolf of Wallstreet

Tolles Computervision-Experiment von Støj: An algorithm watching a movie trailer: „A program removing everything but the objects it recognises when…

C2IJ2mEWIAAzEOf

No WiFi, No Writing, No Higher Brain-Functions, No Matter, No Time

via ‏@carric0che

portal2

Portal on an Apple II

Portal ported to an AppleII in Basic. Not bad. (via MeFi) This is about an Apple II version of Portal,…

c64

C64-PETSCII-Dithering

Schöne Experimente mit Video-Rendering in C64-PETSCII vom Chiptunes-Label DataDoor:

captcha

Miniature-Playground for Captcha-Solving AIs

„I'm not a Robot“ my ass. Mini World of Bits ('MiniWoB') is a benchmark for reinforcement learning agents who interact…

panic

How To build a Marvin the Depressed Reddit Bot in Python

Die Grünen fordern ja eine Transparenzpflicht für Social Bots. Ich hoffe inständig, dass jemand einen angemessenen Marvin-Bot für die Grünen…

nnnames

Neural Network Names from the Future

Nate Parrott hat ein Neural Network auf 7500 Vornamen trainiert und generiert nun neue Namen aus der Zukunft, inklusive „…

floppo

64 Floppy Drives spielen Last Christmas

Paweł Zadrożniaks Floppotron aus 64 Floppy-Drives, 2 Scannern und 8 Festplatten spielt Whams „Last Christmas“ because ofcourse it does. Sein…

ram_01

Mechanical Sand-RAM

Schöne Arbeit von Ralf Baecker, ein mechanischer RAM, der Binärdaten mit Sandkörnern schreibt und damit ein bisschen Voodoo ausrechnet: Random…

homer

Homer Simpson gezeichnet mit dem Problem des Handlungsreisenden

Jack Morris hat einen Algorithmus programmiert, der ihm Vektorgrafiken und Simpsons in Punktierungen umwandelt und auf diese dann das Problem…

Atari 2600-Emulator in Minecraft

Atari 2600-Emulator in Minecraft

Impressive: „I built an Atari 2600 Emulator in vanilla Minecraft using a couple thousand command blocks.“