Programmable Array Logic

[1] MMI obtained a registered trademark on the term PAL for use in "Programmable Semiconductor Logic Circuits".

PALs were used advantageously in many products, such as minicomputers, as documented in Tracy Kidder's best-selling book The Soul of a New Machine.

The FPLA had a relatively slow maximum operating speed (due to having both programmable-AND and programmable-OR arrays), was expensive, and had a poor reputation for testability.

[3] In a previous job (at mini-computer manufacturer Computer Automation), Birkner had developed a 16-bit processor using 80 standard logic devices.

However, the company initially had severe manufacturing yield problems[citation needed] and had to sell the devices for over $50.

[citation needed] PALs were later "second sourced" by Texas Instruments and Advanced Micro Devices.

Early PALs were 20-pin DIP components fabricated in silicon using bipolar transistor technology with one-time programmable (OTP) titanium-tungsten programming fuses.

Prior to the introduction of the "V" (for "variable") series, the types of OLMCs available in each PAL were fixed at the time of manufacture.

Though some engineers programmed PAL devices by manually editing files containing the binary fuse pattern data, most opted to design their logic using a hardware description language (HDL) such as Data I/O's ABEL, Logical Devices' CUPL, or MMI's PALASM.

By 1983, MMI customers ran versions on the DEC PDP-11, Data General NOVA, Hewlett-Packard HP 2100, MDS800 and others.

It was used to express Boolean equations for the output pins in a text file, which was then converted to the 'fuse map' file for the programming system using a vendor-supplied program; later the option of translation from schematics became common, and later still, 'fuse maps' could be 'synthesized' from an HDL (hardware description language) such as Verilog.

The initial release was for the IBM PC and MS-DOS, but it was written in the C programming language so it could be ported to additional platforms.

The development team was Michael Holley, Mike Mraz, Gerrit Barrere, Walter Bright, Bjorn Freeman-Benson, Kyu Lee, David Pellerin, Mary Bailey, Daniel Burrier and Charles Olivier.

The company closed its doors in 1998 and Xilinx acquired some of MINC's assets including the ABEL language and tool set.

They had the PALASM software built-in and only required a CRT terminal to enter the equations and view the fuse plots.

After fusing, the outputs of the PAL could be verified if test vectors were entered in the source file.

After buying out MMI (circa 1987), AMD spun off a consolidated operation as Vantis, and that business was acquired by Lattice Semiconductor in 1999.

Lattice Semiconductor introduced the generic array logic (GAL) family in 1985, with functional equivalents of the "V" series PALs that used reprogrammable logic planes based on EEPROM (electrically eraseable programmable read-only memory) technology.