What’s the crystal next to the microcontroller on the Buffered Grappler+ and what exactly is it connected to? The 1982 Bufferboard schematics show a 6MHz crystal used to generate the 8048 clock on Version 1 boards while the 7M clock from the edge connector is used on Version 2 boards. The 1982 Buffered Grappler+ schematics don’t show any crystal at all. However, the crystal is present in photos of Buffered Grappler+ boards with UVEPROM microcontroller/host ROM as well as the later ones with mask ROM parts, so it wasn’t a particularly late addition.