These days I would forget about messing around with GALs and PALs. At 1-2 $ USD per part you can easily move on over to CPLDs for close to the same cost and yet get the logic equivalent of 16 or 20 GALs in one package of the lowest end parts!! My favorite parts are from Lattice Semiconductor and their parts program from right in the circuit via a JTAG port. A simple cable pod that you can buy off the Lattice web site permits the programming of the parts directly from the Lattice development tool environment. To develop the logic that goes into the parts you can download the Lattice ispLEVER package for FREE!! (Free for use with the smaller parts). Using ispLEVER (which is based in part on the DataIO Senario package permits you to do the design in Schematic Form, ABEL Equation Form, or VHDL language form. Actually any design can be a mix of any of these design methodologies. I very typically use a schematic for the highest level of the design and then segment the design in a heirarchal manner with lower level logic blocks that may be ABEL equations, further schematics, or VHDL blocks.

Michael Karas