I’m using GAL devices in the MC68008 project I’ve been working on. GALs are programmed by writing equations that specify how each output is produced as a function of the various input signals. Before the GAL is programmed, the GAL equations are assembled into a “fuse map” that configures the GAL hardware as specified by the equations. The fuse map is then programmed into the GAL device using a programmer of some type. (I’m using a Wellon VP-190, which also does EPROMs, flash memory, and lots of other devices.) The fuse map is specified in JEDEC format, which is some kind of standard format for programmable logic devices.

I’ve been using a program called GALasm to generate the fuse maps. GALasm was written by Alessandro Zummo, based on an earlier program called GALer by Christian Habermann. It works extremely well, and it’s distributed as source, so you can run in on any system that has a C compiler. I’ve personally used it on both Linux and Cygwin (Windows).

There is one issue with GALasm: the JEDEC files generated by GALasm use bare newline characters to terminate lines. My programmer (Wellon VP-190) requires a CRLF (carriage return, newline) sequence to terminate lines in JEDEC files; otherwise, the file is rejected with a cryptic error message. So, I modified the GALasm source to always output CRLF for line termination in JEDEC files.

I posted the modified version on Github:


The GALasm source code is becoming increasingly hard to find, so having it on Github might be useful for other people who want to program GALs.

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