[(*steve*)]

I've got a few chips that are described as being either PALs or GALs and I wonder what I can do with them.

I realise they require programming.

Is there something that teaches a beginner how to do this? I don't have any objective particularly in mind other than learning.

I guess I also need to find out if programmers are available cheaply because I'm not going to spend $hundreds for some "rainy day" tinkering.

 

[davenn]

Haven't heard of PAL's ... PLA's (Programmable Logic Arrays) yes, will be interested to see what others may have to say

Dave

 

[Ian]

I did some googling as I'd not heard of these and found a little bit more about them:

http://en.wikipedia.org/wiki/Programmable_logic_device#PAL

PAL:

MMI introduced a breakthrough device in 1978, the Programmable Array Logic or PAL. The architecture was simpler than that of Signetics FPLA because it omitted the programmable OR array. This made the parts faster, smaller and cheaper. They were available in 20 pin 300 mil DIP packages while the FPLAs came in 28 pin 600 mil packages. The PAL Handbook demystified the design process. The PALASM design software (PAL Assembler) converted the engineers' Boolean equations into the fuse pattern required to program the part. The PAL devices were soon second-sourced by National Semiconductor, Texas Instruments and AMD.

After MMI succeeded with the 20-pin PAL parts, AMD introduced the 24-pin 22V10 PAL with additional features. After buying out MMI (1987), AMD spun off a consolidated operation as Vantis, and that business was acquired by Lattice Semiconductor in 1999.

There are also PLA's : Programmable Logic Array.

GAL:

An innovation of the PAL was the generic array logic device, or GAL, invented by Lattice Semiconductor in 1985. This device has the same logical properties as the PAL but can be erased and reprogrammed. The GAL is very useful in the prototyping stage of a design, when any bugs in the logic can be corrected by reprogramming. GALs are programmed and reprogrammed using a PAL programmer, or by using the in-circuit programming technique on supporting chips.

Lattice GALs combine CMOS and electrically erasable (E^2) floating gate technology for a high-speed, low-power logic device.

A similar device called a PEEL (programmable electrically erasable logic) was introduced by the International CMOS Technology (ICT) corporation.

Apparently WinCUPL can be used to program them (link : http://www.atmel.com/dyn/products/t...2&family_id=653&subfamily_id=734&tool_id=2759).

From what I understand, there's also an easy to build GAL programmer here: http://elm-chan.org/works/pgal/report_e.html

Not even heard of these before, so I hope the above is some help rather than me going off on a tangent

 

[davenn]

Hey Ian,
havent heard from you for a while. yes that wiki page was rather enlightening
thanks for the link

Dave

 

[Puno]

it is interested to know if that works cause we have fire panels as training aid for students and the chips in them are GAL 16V8B which I have been ordering spares from UK as they are programmable none around AUS and NZ dealers but has to order from main manufacturer. I was thinking that a few years ago to build one but not sure, I mean should I put the programmed chip on get it read and then program a blank one not so sure how they work so I abandoned the idea as I ordered 6 spares as the students do smoke them out now and then (from faultfinding exercises).

 

[Trungy]

I work on a product line that has 5 PALs/GALs (we've found some of them to be interchangeable). Are there any PALs/GALs readers out there for those who want to know what programmed chips are doing?