MMI invented the PAL, which has been one of the most commercially successful programmable logic devices. Many of the early PAL types have long since been obsoleted (anyone remember the PAL16C2?), but some of them like the PAL22V10 are still commonly used today.

Part of the reason for the success of the PAL family was that MMI gave away the PALASM software needed to develop for the parts. PALASM took logic equations and produced fuse maps and JEDEC object files. PALASM was written in Fortran, which may seem strange today, but in the early 1980s Fortran was still one of the most widely available programming languages. The source code for PALASM was published in the PAL data book.

MMI was one of the major vendors of bipolar PROMs, and PALs were fabricated using the same technology. For some logic functions, PROMs are a more effective solution than PALs, so MMI for a while offered a line of PROMs under the name "PLE", Programmable Logic Element. PLEASM was the equivalent of PALASM for use with PROMs or PLEs.

MMI was eventually acquired by AMD. AMD later spun off their programmable logic division as Vantis. Vantis was acquired by Lattice Semiconductor.

Here is the Fortran source code for PALASM20, PALASM24, and PLEASM. I'm not sure whether these source files are from the data book; they may be older or newer versions. If you have other versions in source form that you can contribute to this archive, please let me know.

Later versions

Later versions of PALASM were generally not offered in source code form, and were not freely redistributable. Reportedly PALASM 4 V1.5 for MS-DOS has been put into the public domain. A copy may be found at Additional documentation on PALASM 2 may be found at

PALASM 2.3d for MS-DOS may be found at

Going Backwards: From JEDEC Files to Equations

It is frequently asked whether there is software to generate logic equations from a JEDEC file. Utilities were available to do this for a limited number of devices.

Last updated May 14, 2004

Copyright 2002, 2004 Eric Smith

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