PLAster offers improved compatibility over other PLA replacements, such as the dual GAL PLA. All pins offer evenly-timed response due to all being on one chip. The chip is 5V native, offering the strongest signal and best reliability and also TTL compatibility. The CASRAM pin is perfectly timed, and even offers an optional delay for flexibility.


The U17 PLA is the most common chip failure in earlier Commodore 64 revisions and can result in a black screen.

Replace your PLA with PLAster™ for Commodore 64 U17:

·         Acts as fully compatible replacement for the U17 PLA chip in most breadbin/longboard revisions including a few very early C64C models;

·         Fully compatible with Super Zaxxon and Epyx Fastload cartridges

·         Works in revisions 326298 (original), 250407 (A), 250425 (B), and 250466 (B3);

·         Not compatible with short boards, i.e. 250469, since those have a 64-pin mega-PLA;

·         Configurable CASRAM delay of 25 or 30ns with DIP switch;

·         When C64 version is used in conjunction with BackBit cartridge, allows for software controlled KERNAL replacement (with DIP switch setting);

·         "Eyes" switch quiets bus to assist with troubleshooting.

 

Also available as open source here: https://github.com/evietron/BackBit-OpenSource