C = HR4988
E = A4988
A = TMC2208
B = TMC2209
H = TMC2225
Seems that depending on how the SD card slot is labeled with a sharpie, you will have different driver versions. Understanding was that it was incompatible with stealthchop? on one or two of the TMC drivers. I guess I might have to dig in one night here and try building FW.
I’ve got a board labeled E.