NCR 8496 is what you're looking for, but I'm not happy to admit that the one I bought was the only one for sale on ebay. More power to you if you can find it. The chip should be found in SX/EX/TX tandies but I read that its possible for an SX to have EITHER the more common TI or less common NCR chip …

Long time lurker, first time poster. I purchased a TNDLPT from Serdaco but noticed that it didn't render the music in Maniac Mansion or Zak Mckracken quite right (the noise tracks dropped out). No fault of the TNDLPT design, it was actually because the original TI chips used in the PCJR and widely …