keith
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...
Why simply “dumping” a PAL isn’t always possible?
Contents Rom Dumping Dumping ROMs is a pretty common practice in the space of reverse engineering, and many eeprom readers are cheap, easily available, and there’s really not much to them. Plunk your ROM chip in...
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...
My PAL stimulator
If you’ve been following my blog, you’ll see that I’ve been reversing a Commodore Amiga SCSI HDD Expansion card called the Dataflyer. On that Dataflyer, there’s a PAL that handles address...
Commodore Amiga AutoConfig expansion card process
Since I’ve been reverse engineering a DataFlyer Plus HDD SCSI expansion card for the Commodore Amiga, I’ve needed to get a much better understanding of how the AutoConfig process works. I’m by far no...
Dataflyer 500 reversed schematics are coming….
While trying to reverse the function of the Commodore Amiga Expansion Systems DataFlyer 500 BUSS PAL, I really needed to know what was connected to what. There are no, as far as I know(!!), schematics available for this...
Building a PAL reader for TL866A
So I’m in the process of trying to reverse engineer some custom PALs from a Commodore Amiga Dataflyer 500. It would be ideal to read those PALs directly, however I don’t have a compatible PAL reading...
Some reverse engineering notes on DataFlyer 500 BUSS Pal
As you may have seen in this other post here I have an interest in this Amiga hard drive controller designed for the Commodore Amiga 500. I used this for years to interface an HDD. At the time I took some photos of the...
2-wire digital voltage display accuracy
I had a few needs to for a simple voltage display that can handle the range of +5v to +12v. There’s a few different applications like displaying the state of a battery, a state of a power supply and so on. I was...
Refilling Star Micronics NX-1020 black ribbon ink cartridges
I have an old Star Micronics NX-1020 Rainbow printer from circa 1993. I bought this printer using my paper route Christmas money that I saved up for months. The printer served me valiantly throughout the early 90s. This...
HP Agilent 5382A tear down with photos
I recently tore down an Agilent E5382A Flying Lead Set. I used a Torx T-4 bit to remove the (4) tiny tiny screws. This adapter has a 90-pin connector that comes from HP logic analyzer cards, and then goes out to single...
Setting up a SCSI2SD on HP 167xxA for CDROM and HDD targets
This quick guide contains instructions on how to setup, configure, burn, and launch an install from a SCSI2SD when inserted into an HP/Agilent Logic Analyzer on the 16700 series. A fresh install is always recommended...
Evaluating Battery Backup Solutions for CPAP machines
I recently had a need to provide a battery backup solution for a CPAP machine. A CPAP machine helps people, who suffer from sleep apnea, get a good night’s rest. About 20 million Americans suffer from this...
Amiga MAST enhanced unidrive external drive teardown
Back in the Christmas of 1991 or 1992, my parents bought me an external floppy drive. It was $129, which was a lot of money back then. The equivalent price would be about $245 after inflation. I probably found this...
How to mount HPUX 10.20 VxFS logical volumes in a modern linux environment
This is a problem that I’ve wanted to tackle for quite some time. Since I’m using SCSI2SD and also messing around with a few different logic analyzers, I’ve got several HDD images that include both...
Corrosion near/underneath HP Logic Analyzer module plastic runners
The problem is corrosion….. Corrosion appears to be happening either directly under or nearby the various sized (but typically 5″ long) plastic runners that line the bottom of the large PCB modules. These...
Effects of upgrading SCSI2SD from v5 (4.8.3) to v6 (6.2.1) analysis HP 16700A
If you compare this graph with the previous one in this post, there’s a few things you should notice: First, the overall boot is happening about 1 minute quicker, with a fully loaded chassis coming in around 2:35...
