We are at version 2.3 now so that the red version preamp will run with a version 4.2 and higher computer. Several users wanted to upgrade the red systems to incorporate features from the orange systems. The part is a Microchip PIC 16C57-XT/P. Set the programmer for WDT off and OSC to XT. Checksum is 768C. Any questions you can e-mail me Ross Blomgren Chief Engineer