Author: root42

PSU Battle: Commodore vs Electroware

The original power supplies of our Commodore home computers are now at least 30 years old. Many need maintenance, some got lost or are defective. There are modern replacements. But are those any good? Are they better or worse than the old supplies? In this video we will compare my original Amiga 500 supply to a modern Mean Well based PSU by Electroware. We will mostly compare the ripple that both PSUs produce, which is one of the main factors that could disrupt the functionality of a computer.

Amiga500: Lazarustorm/PiStorm vs ACA500plus

The original Amiga 500 is a great machine, but its 7MHz CPU is a bit slow at times and the 512K of base memory quite limited. We take a look at two accelerator cards that increase the CPU speed significantly and also bring a large amount of extra memory to the table. All the while these cards don’t require you to open up your A500, but instead they fit on the expansion slot on the left side of the Amiga, making the process very easy and reversible. Let’s take a look at the PiStorm based Lazarustorm and the Individual Computers’ ACA500plus.

Let’s Code MS DOS 0x28: Expanded Memory (EMS)

The original IBM PC and MS DOS could — for the most part — only access 640KB of memory. The LIM EMS standard was at first a standard for RAM expansion cards to overcome this limit. On later machines like the 286 and 386 there was either support built into the chipsets or EMS memory was emulated via drivers like EMM386. Today we learn how to utilize EMS memory to play back an animation that is too large for conventional memory.

Low-Noise 7805/7812 Drop-In Replacements

Linear voltage regulators such as the 7805 and 7812 are ubiquitous in vintage electronic equipment, and especially in home computers of the late 1970s and early 1980s. They have many advantages are very reliable. Their biggest drawback is their heat dissipation. The variants in metal TO3 packages are only available used or as new old stock. So if you want to replace them with a cooler running variant these brand new drop in replacements based on modern switching regulators might be worth a try. These particular variants have extremely low switching noise, so should be very usable in devices such as the Commodore 1541 floppy drive. So we will repair one of my broken 1541s and also fit it with the modern DR340 voltage regulator!

Original GameBoy: IPS Mod Horizontal Lines

The IPS display mod for the original GameBoy from a couple of weeks ago already developed a fault. bright horizontal lines run through the display, and it seems a full replacement of the LCD panel is needed. It seems these mods are a bit fragile. Also the display lens is a bit crooked and needs fixing. So off to another round of DMG modding!

Original GameBoy IPS Mod

A friend gave me two GameBoys, one of which he wanted back after the repair. The other one was dead and I could keep it. So after a quick testing I determined that only the display board was broken due to quite severe battery damage. While maybe salvageable I decided to use a drop in IPS LCD replacement board, as the original DMG screen is pretty abysmal anyway. This mod is relatively easy to install, and requires no soldering!