techtravels.org

Hands-Free Debugging: Reviewing Gisler Precision’s Probe Holders

Disclaimer: While I purchased these myself at full price, Gisler did pay for shipping. This is my own opinion. If you’ve ever tried to hold multiple scope probes steady during debugging, you know how frustrating it can get. I tested three...

Building a replacement Amiga 500 power supply

Intro If you’re into retro computing, you probably know the Commodore Amiga 500—a beloved classic with surprisingly capable hardware for its time. But like many vintage systems, the original power supply is often a weak point after decades of...

Validating my dataflyer BUSS PAL replacement GAL

As some of you that have been following my reverse engineering efforts over the last few years, one of the tasks I took on was reverse engineering the BUSS PAL TIBPAL16L8-25 present in on the Expansion Systems Dataflyer plus SCSI-ONLY card. My PAL...

Recapping a Samsung 204B monitor

In September 2006, I bought a Samsung 204B SyncMaster monitor for $320 plus tax. It was a 4:3 monitor, ideal for specific tasks like my Logic Analyzer Cart. In July 2024, the monitor stopped working and wouldn’t power on. The only sign of life was a...

Amiga QB Extract recently updated

There was a HDD backup utility for the Commodore Amiga called Quarterback, part of a suite of tools called Quarterback Tools. This utility allowed you to backup existing files on your HDD, compress and/or encrypt them, and split them across multiple...

Creating a timeline of events

It’s often useful when trying to understand, debug, or reverse engineer a system to put together a timeline of operation from beginning to end. The result is a series of events where something happens first, then...

Identify PAL inputs and outputs

In order to properly reverse engineer a PAL, you need to correctly identify which pins are inputs, and which pins are outputs. This in some cases is trivial because some of the PAL’s pin functions are fixed...

Understand the system

Of all of the different techniques this one may be the simplest but also the most important. When you’re trying to reverse engineer something, understanding the system is key to unraveling the black box which is...

New Reverse Engineering PALs page

I’ve recently put a new page online on the site. It hosts a basic outline on different techniques to enable one to reverse engineering a PAL, and produce a modern equivalent. Right now, there are about a dozen...