I have a number of HP 8510's - not a calculator, rather vector network analyzers - the tape drives have the gummy capstan wheel problem common to HP 85's. I am considering using a PC to emulate the tape drive and therefore eliminate the risk I have with my 8510's. Does anyone have the detailed interface specifications for the tape drive? All I have is the hardware interconnect diagram (in the 8510 manual). Any thoughts on this approach?