Author: root42

Remember the clicking sounds of spinning hard disks? One “problem” with retro computing is that we replace those disks with Compact Flash, SD Cards or even SSDs. Those do not make any noises that you can hear under usual circumstances. Which is partly nice, because the computer becomes quieter, but also irritating because sometimes you can’t tell if the computer has crashed or is still working. This little device fixes that issue! It’s called the HDD clicker and it’s a very unique and funny little gadget!

In this video I will show you how to assemble your own SEGA MegaDrive/Genesis cartridge, using an erasable programmable ROM chip, a so called EPROM. Those can be had for relatively small money, used on eBay, for example. You also need an adapter for the popular TL866II+ programmer, to be able to read and write EPROMs up to 32 Megabits (4 Megabyte) in size. This can be used to make your own repro cartridges of rare games, homebrew or demoscene productions.

A user from the DOSReloaded forum sent me his dead Roland MT-32, arguably one of the most sought after and iconic synthesizers for playing vintage DOS games. This item is said to be totally dead, no LCD display and no sound. So let’s have a look at what’s wrong and if we can fix it!

Marco Roth reverse engineered a broken M396F mainboard, powered by a 386SX CPU. This tiny Baby AT sized mainboard comes with six 16 bit ISA slots, four 30 pin SIMM sockets, a 40 MHz AMD branded 80386SX CPU and is a fancy purple color! Does it work? Let’s throw some soundcards and games at it and see how it behaves! Marco didn’t have a lot of cards to test with, so I offered to do it for him. Let’s see how it turned out!

I was asked by a viewer if the Roland SoundBrush that I showed in an earlier episode can also be used to record MIDI music from a PC. And yes of course, it can. With some caveats though! I connected the SoundBrush to my 486 PC and tried a few games. Lucasfilm games were running into buffer problems on the SoundBrush, but Sierra games were playing nicely. Let’s have a look and a listen how you can wire up the SoundBrush, format some floppies and record some MIDI files!

In this episode we learn how to program a little tic-tac-toe game for two human players. No AI, just the input and output and the winning condition! We learn different methods to compare registers and memory locations, different conditional jumps and how to save a few bytes by replacing CALL instructions with JMP.

I have a couple of broken 1541 floppy drives for the C64 and similar machines. Some have broken mechanisms, of Mitsumi variety, where the read coils are fried, but also one drive that has supposedly some PCB issues. Let’s see if we can assemble a Frankenstein 1541 drive by taking bits and pieces from each drive!

In this episode we learn how to declare variables in assembly language. Also we learn how to access data from pointers stored in registers. We learn a couple of jump instructions and how to loop. We use this knowledge to compute all prime numbers below 1000 and print them to the screen. As usual this is based on the book “Programming Boot Sector Games” by Oscar Toledo.

Last time we restored Ocarina of Time to its former glory, this time it’s Majora’s Mask. This N64 cartridge was hit by last year’s flood, which besides hurting lots of people also claimed the less important artifacts, such as retro game collections. Here we have one example of a cartridge that was salvaged by the owner, before he sold it to me, untested. Let’s see if we can clean it up and get it going!

In this episode we learn how to use the DIV opcode for dividing integer numbers, how to print integer numbers to the screen, as well as how to use a debugger to understand what our program does. In all coding tasks looking for errors and understanding what the program actually does is a key aspect. So a debugger (here we use the Turbo Debugger by Borland) is a very useful tool that every developer should know how to use.