"Bill Sudbrink" <wh.sudbrink at verizon.net> wrote: I have always found it interesting how quickly people comment on issues without first studying them in depth. :-) The TG43 signal is entirely absent from the 16FDC drive connector and no cable mod alone can correct that. The board modification brings the signal carry it to the drive. If you choose to operate the SA-851 out of spec, it is certainly your right. I chose to make my 16FDC compatible with the drive's operating requirements. Incidentally, the Shugart SA-800/801 doesn't require TG43 and will work with just a cable mod (or maybe no mod at all since that drive is single sided). Almost every newer drive, including SA-851, however, will have higher error rates on the inner cylinders without the reduced write current controlled by TG43.