Author: root42

So you always wanted a Roland MT-32. Even as a kid you saw it in ads, and in the setup programs of games. But it was way to expensive. And today you still will pay upwards of 250 EUR for a working device, which is more than 30 years old. So why not emulate it? There is now a Waveblaster compatible module that will fit on many retro sound cards and which is able to emulate the MT-32 as well as SoundFont based GM and GS compatible synthesizers.

The SEGA GameGear that we revived in the last video gets a new shell! The old one was beaten up pretty roughly. And new shells in all kinds of colours are still made to this day. At the same time I will be replacing the electrolytic caps with small SMD ones. I disliked how the electrolytics were all over the place, making the shell hard to close. However something went wrong in the end, due to my own negligence…

I have had this SEGA GameGear lying around for a couple of years. I got it very cheap, because it was sold as broken, for parts. It came with a few games and the TV Tuner. Upon trying it out I noticed the power comes on, but all else seems dead. The GameGear is prone to have very bad capacitors, so that is the first order of the day: recapping! This and a modern LCD replacement are what we are going to tackle in this episode!

This is part three of our x86 assembly series. In this episode we learn how to do simple single character keyboard input. We use this to code a little game “Guess the number”. 

The Commodore DM602 is a small 10″ monochrome CRT, which pairs nicely with the VIC20 or C64. It has a built in speaker and a nice, very bright and sharp picture tube. This particular screen has a tiny problem, namely the video input socket broke off the PCB, so we will have to repair that. Also we will compare using different video cables on the C64, composite and YC (Luma/Chroma). This has some interesting visual side effects on the CRT.

For this year’s Christmas Episode of Let’s Code MS DOS we are revisiting Power BASIC and will be coding a very seasonal snowflake. It will be based on the Koch curve, especially implemented using an L-system. This is a rather easy system to describe fractal structures. It is not as hard as it might seem and you will be able to adjust the curve to display different things.

The Commodore 16, or C16 for short, is one of the few machines that Commodore designed and produced in the mid 1980s based on the TED chip. They were supposed to be cheap, entry level home and business computers mainly geared towards text display. But they also had some graphics and sound capabilities. They sadly fell short of their goal, mainly due to the fact that founder Jack Tramiel left Commodore and new management didn’t really know what to do with the TED machines. The C16 is a brother to the more sci-fi looking C116, but comes in a classic C64 style breadbin. We will have a look inside, upgrade it to a more usable 64KiB of RAM, and play some games and demos on it!

In our second episode of the x86 assembly programming course we learn about how to do simple arithmetics on the 8086 and compatible processors. We also set up a simple NASM library for outputting digits to the screen. 

Back in the early 90’s the Canadian company Gravis came out with a range of sound cards called “Ultrasound”, or GUS for short. They were meant to be Adlib and Sound Blaster compatible, as well as having a versatile Wavetable synth, which could be populated with custom samples. It was similar to what the Amiga did, but with way more concurrent samples or channels.
The Sound Blaster compatibility was lacking at best, or non functional in other games. So at one point Gravis left out all that made the GUS compatible and simply put the Ultrasound part on a card called the Audio Card Enhancer (ACE). This card is very sought after nowadays, as you can simply plug it into a retro machine alongside an existing SoundBlaster card. Let’s have a look at it!

In my Let’s Code MS-DOS series we already did a little bit of assembly language. However I think it is more fitting if I start a new series on x86 assembly, as I want to keep the original series so that it uses only C and BASIC.
This series will use Oscar Toledo’s book “Programming Boot Sector Games” as a guideline, and we will use examples from his book as a foundation. Many thanks to Oscar for allowing me to do this.
In this first episode we will start off simple, with the classic “Hello World” program.