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 topics/techniques, with no content beyond basic background information.
As time goes on, I’m going to add more and more posts, with the page serving as the outline, index, with centralized links.
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 configuration (the latch), chip selects, and converting the 68000 signals to those the peripherals understand.
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 expert on it, but I have learned a lot and wanted to share a couple logic analyzer traces of this occurring in the wild. The Commodore documentation refers to these expansion cards as PICs or Plug-in Cards.
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 board, so I thought I’d bring that to end.
I will be publishing schematics relatively soon once I’ve had some more time to double-check them.
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 solutions. I’ve found some online but they are easily $800-$1200. So someone on a previous blog post commented about a potential solution that works with the TL866A eeprom reader.
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 fairly interested to know how accurate these displays are considering they are only a few dollars each. I ordered these from Amazon.
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 is a 9-pin dot matrix printer and was based on popular designs available from Epson, Okidata, and others.
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 ended flying leads for direct connection to the System Under Test.
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, just like for other operating systems like Windows. I do not recommend imaging your previous SCSI drive, and then trying to burn it directly onto the card.
I’m using a 32GB SD card for this. You’ll need to play with the sector count field if you vary from this.
