dowson@utecfa.UUCP (Jim Dowson) (02/04/86)
I am trying to hook up a CDC 9877 (BK5XX) 80 Mb removable storage SMD drive via a CDC 9090 multibus interface card to a Xenix system (3.0). The pertinent specs for the drive are: 1) 20,160 bytes/track 2) 5 tracks/cylinder 3) 823 cylinders/spindle 4) 13,440 dibits/revolution (? allegedly) The pertinent facts for the controller are: 1) 512 data bytes/sector 2) 63 bytes control information/sector Here's the problem: There are formulae in the installation manual that are as follows: SL = 13440/RS (ignore remainder) where SL = sector length RS = required number of sectors (/track) 13440 = total dibits/revolution PV = 4096 - SL where PV = preset value to be encoded by the DIP switches Here's how I (tried to) figure it: SL = 13440/35 = 384 (I want 35 sectors/track) PV = 4096 - 384 = 3712 However, this doesn't work, nor does +/- 1 ... Frankly, I don't understand where the 13,440 number came from - so I even tried using 20,160 (the number of bytes/track) ... that didn't work either. In all cases the error code from the controller indicated "sector pulse not found"..... Help ...... Please mail responses to: {ihnp4,allegra,decvax,linus}!utzoo!{spectrix,utecfa}!bml!jim Jim Dowson