In einer eMail vom 04.05.99 21:47:46, schreibt Tony: << easier OK, here you are. The pin layout on the connector is something like : A B C D E F H J K L M N P R S T U V W X Y Z AA BB CC DD EE FF HH JJ KK LL MM NN PP RR SS TT UU VV WW XX For a total of 42 pins (I am not sure if that's looking at a plug or a socket, but it should be a start). A Read Clock B Write data and clock C Read data D Ground E Read gate F Ready to read/write/seek H Write protect input J Track select 8's K Erase gate L Drive select 1 M High density N Track select 2's P Write protect status R Drive select 2 S Pseudo sector mark T Track select 64's U Drive ready V Drive select 3 W Sector marks X Track select 16's Y Index marks Z Drive select 4 AA Head select BB Track address 128's CC Sector address 1's DD ground EE Write gate FF Track select 32's HH Write check JJ Sector address 2's KK Sector address 4's LL Track select 1's MM Sector address 8's NN Address acknowledge PP +5v for cable terminator RR Track select 4's SS Strobe TT Seek incomplete UU Sector address 16's VV Restore WW ground XX Illegal address If you need descriptions of any of those, let me know - I have the full service manual for the Diablo. -tony That is EXACTLY what I need - the connector has the letters above imprinted, and the meaning of the signals I have from the DEC docs. This is precisely the RK-11 Drive Bus. Thank you _VERY_ much! Regards John G. Zabolitzky