I have the old data sheets. Was the R65C19 ever produced? I leaned Forth on the AIM-65 and remember looking forward to writing a Forth for the threading enhanced chip.

The R65C19 was produce mainly for PC MODEMS. I had used the R6501Q for some controllres in the '80's & when I talked to an app engineer at Rockwell in the early '90's, he recommended using the ROMless version of the R65C19. Unfortunately, the project was canceled. I still have some samples around somewhere. Later chips, the C40 & L39 were used in most 14.4 MODEMS. I've collected a few old MODEMS to use the chips "someday". They were 20 MHZ in about 1994.