Repairing a Commodore 1541 Floppy Drive

Some time ago I acquired a very affordable Commodore 1541 drive. This is the original one that came with the earliest C64s, and it is an absolute unit of a floppy drive. It contains a pretty hefty transformer and lots of metal parts. This device came es untested/defective, and sure enough: both LEDs stayed on after power up. So I took to it to try and get it repaired.

Let’s Code MS DOS 0x1C: The Dweezil Fractal Zoomer

Back in 1993 two Finnish demoscene coders by the names of Dweezil and Tsunami came up (probably independently?) with a graphical effect that became known as the infinite fractal zoomer. Sometims it’s also called the Dweezil zoomer. The Linux xscreensaver knows it by the name of Kumppa. It is a clever and simple algorithm which allows even pretty slow machines to do an impressive infinite rotating zoom. Today I will talk you through the algorithm and we will do the actual implementation in Turbo C, using VGA 320×200 and 256 colors.

Learning SMD Soldering – With LEDs!

I love those little SMD soldering kits for practicing manual surface mount component soldering. They are only 2-3 EUR each and you can practice your skills before you try and repair you precious vintage hardware or broken modern console or laptop. This time I got a nice kit from a Chinese seller which includes (Chinese) instructions and actually can be tested without a testing harness, simply by looking at the LEDs. So let’s do some soldering!

Upgrading the Commodore PET for “Attack of the Petscii Robots”

For Christmas I got a surprise: a 1979 Commodore PET 3016. This is the predecessor of the VIC20 and C64 and comes stock with 16 KiB of RAM. Last year Dave Murray, better known as the 8bitguy, announced a brand new game for the PET, called: Attack of the Petscii Robots. So this was a lucky coincidence! I ordered a boxed copy of the game and also ordered a PCB and parts to build a 32 KiB RAM expansion for the PET. I showed the soldering and assembly of the expansion in a previous livestream. However we still need to install and test drive both the PET and the game! So that’s what we’ll do today.

MegaDrive Megademo: Overdrive 2 by Titan

Not only the Amiga has an active demoscene! The SEGA MegaDrive (also known as the SEGA Genesis in other countries) has seen some magnificient productions over the last years. Let’s have a look at Titan’s Overdrive 2 Megademo. It is amazing what the coders were able to get out of this late 80s, 64KB tiny machine.

My 2nd Most Favorite Amiga Demo

The other day I published a video about The Electronic Knight’s new demo called “Hologon”. It seemed that a lot of people liked that video. So I want to show another of my most favorite Amiga OCS demos. This time it’s EON by Black Lotus. There are not terrible many new effects, but everything is highly polished, making this demo a true piece of art.

Learning SMD Soldering 2: Learn Harder

We already soldered one SMD kit, which allows you to practice the difficult task of soldering surface mount components. Now we try another kit with a bit more difficult components: two QFP44 ICs are in the kit as well as the usual array of resistors, capacitors, diodes and transistors. I will show you some techniques and tools for this job and hopefully we get better at soldering SMD stuff!

Brand New Amiga 500 Demo on Floppy Disk in 2021?

The demoscene has been part of Amiga (and PC) culture for at least 30 years. Of course there are still great demos and intros released for all kinds of platforms. I love when the Amiga OCS machines (A500, A1000, A2000) get some kind of love, but getting a brand new demo ONLY on floppy disk, and not for download, is something special. This is Hologon by TEK (The Electronic Knights) — let’s watch it!

Let’s Code MS DOS 0x1B: Fixed Point Arithmetics Rotozoomer

In the last episode we learned how to code the rotozoom effect using floating point arithmetics. This however is pretty slow on ancient DOS machines, like 486 and even worse on slower machines. So in this episode we will rewrite the program to use integer based fixed point arithmetics.

Let’s Code MS DOS 0x1A: I Am Not An Atomic Playboy! (The Rotozoomer)

Back in 1993 the Future Crew published „Second Reality“ on the PC. This was a mega-demo of epic proportions. It showcases many new and some old effects with a brilliant soundtrack. One of the effects that was very well done and that stuck in my mind was the „rotozoomer“. A tiling image being rotated and scaled in a very fluent animation. As a kid I wondered how it’s done. Later I learned the maths behind this and today we want to explore this simple yet brilliant effect. In this part we will deal with the basics and implement a floating point version. However the original code used fixed point integer arithmetics, which we will visit in a second video…