Help to copy PAL16 / GAL16 / GAL20 ICs

The protection you mention refers to disabling a device programmer's ability to read the JEDEC fuse pattern burned into the PAL during initial programming. It's more commonly referred to as the 'Security Fuse.'

If the security fuse has indeed been blown, you will not be able to read the PAL in question. Reverse-engineering is possible, but it will likely require a logic analyzer. It will also most definitely require schematic diagrams of the circuit in question, showing how the PAL you're trying to reverse-engineer works into the circuit. Source code for the circuit's microprocessor for the specific application may also be of assistance (good luck).

As far as a programmer goes, the Pilot MVP is an excellent choice. Don't think of it as "more than you need." Think of it instead as a relatively future-proof investment. It is a tool, and a quality one at that, one which will serve your needs for much more than just PALs.

Such training could be hard to find. I'm not a good choice, as my knowledge of such devices is still at the "basic" level, and I don't make a very good tutor in any case (wrong personality for it). I would suggest checking with your local community colleges for electronics courses involving basic digital logic and PALs.

Happy hunting.

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Rich Webb   Norfolk, VA

Ebay is a good bet. I picked up a BP-MICRO PLD programmer (1126 I think ... dont quite recall the model number) almost a year ago. Works great, downloaded (and BURNED to cdrom) a copy of their software from teh online site.

I have used it successful for 16L/R/V8 22V10s which are the type of PALS I buy from ebay in bundle.

I bought the TOP-8048? USB Universal programmer. Thats worked well too, with 27Cxxx etc.

Good luck

Used to have a BP programmer, it was great and never let me down unlike some of the others I've have during the years.

Henry, if you can read out the fuses from the PLD's, there was a free program called Pal2gal, or something like that, that would automatically alter the fuse pattern for you to use a generic GAL. This was an old DOS program that was distributed by either Lattice of AMD (I think, its been a long time).

Good luck.

Yup. Right the 1st time. RSW has it. http://64.233.167.104/search?q=cache:FmTUSBQCDCMJ:

Just a brief update if anyone cares. There is hope, if anyone in the future has found these threads and was in the same boat as I. Seems there are a few options available to people with PAL's (not sure if this will work with GAL's, but I'm also going to try) that may be "protected" and need to copy them.

I first found a service that used a Brute Force Analyzer to try to recover and create a JEDEC file from my PAL's. After they had some issues with the analyzer, due to the age of the machine, I then found a buddy who had a few good ideas on working with HAL's from the early Mac's. His idea was to expose the silicon "chip" so it could be examined by a microscope. Once exposed pictures could then be taken of the "fuse field" that is inside a HAL/PAL (see data sheet of PAL if you never seen the "fuse field") and it could then be possible to recreate a JEDEC file, manually of course. I'm a basic idiot (due to frequent parental droppings and lack of experience) and probably would have never occurred to me to try such a thing.

He tried a few different ideas to expose the chip, but most were unsuccessful. His Website chronicles different ideas and stages of things he has tried. The address is

to see some failed attempts. The real good stuff is here: Take a look around the whole site. He's really quite smart.

Anyway. he found a service that will "decap" the IC, called MEFAS.com. They do failure analysis, so really we just use "part" of the services they offer. If you visit their Website you'll see that they offer a LIB service. Basically they can "jumper" the security fuse and then you will be able to "read" the JEDEC file from the PAL. Right now I have a HAL I sent to be decapped ($175 with return shipping, pics are more if you need them, about $350 total). There are issues with HAL's that I go in to in a moment that the LIB process won't work. The idea with the HAL is simple - I found a version of a HAL (from an Apple IIe) that was in PAL form. Luckily I was able to read the PAL with my programmer, convert the PAL code to GAL form and burn a working GAL. Sounds like quite an accomplishment? Naaa. If any unschooled idiot like me can do it, trust me - you could too. Anyway, converting the PAL to a GAL is just kids play - the real luck with this is that I found a PAL which I could read. Since I know the HAL is identically the same, programmed and logic (fuse field), then I can use the JEDEC as sort of a "Rosetta Stone" to read HAL. I could have purchased some old PAL's (and YES they are still for sale in some places!) and burned a few and had then decapped, but knowing the JEDEC file AND having a piece of equipment to test the PAL with is really quite a find!

Now for some HAL info. These things are VERY rare. I'm not too sure if anyone outside of Apple even used them. Basically they are the same as a PAL, but they lack the "programming" circuitry that a PAL has. A PAL can be programmed "in the field" where as a HAL could only be programmed in the factory. HAL's were made by request only. They were a way to "mass produce" a PAL, which is just a custom piece of logic. The HAL was programmed, or burned, while in the manufacturing process. Since the manufacture had access to the bare chip they didn't need any of the programming circuitry and that helped keep the cost of the finished IC down since it was a "simpler" IC to produce. Since a HAL lacks any programming circuitry it also can't be read, so it acts as a copy protection like the security fuse does in a PAL. Oh sure, you can read a HAL if you want to try, but all you'll get is a "block" of un-blown fuses somewhere in a JEDEC file. Nothing useable that will let you recreate the IC. So since HAL's don't have a security fuse the LIB process offered by MEFAS.com won't help much.

Hopefully I won't need to manually decode my PAL's. I'm hoping to just have MEFAS.com "jumper" the security fuse back and be able to read it. Feel free to contact me if I can be of any help in the future. I can be reached via email on any of these two sites:

and My email is listed on both sites.

Thanks again for everyone's input. My next project involves recreating some of the PAL logic in CPLD's. If anyone is familiar with CPLD's and their programming, please get in touch with me. I could use some help!

Henry

GSE-Reactive.com

My email is listed on the site if you wish to contact me directly.