Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
If you really decided to learn GAL and PAL (not FPGA and CPLD), the best way is to go to the official site of Lattice: https://www.latticesemi.com/
There you will find everything you need: parts, datasheets, cable schematic, 6-months trial development tools etc.
There are many compliers such as Palasm, wincupl integrated in protel can work with GAL.
Besides complier, a GAL programmer is needed, buy universal programmer and you can start immediately. If you like to built one yourself, seach on the web for circuit. There are many design.