ngeow@bu-cs.BU.EDU (Yee Ngeow) (11/27/89)
Hi! I recently obtained a Quantumn Hard disk, model 520. Can anyone who know the drive parameters let me know what they are? Specifically I need to know: (Just fill in the blanks) Cylinders : Heads : Format MFM/RLL : Reduce write cyl: Write precomp : Error corr. bits: Step rate : Please email if possible to ngeow@bu-cs.bu.edu (internet) or engkdfc@buacca (bitnet) Thank you very much in advance! Yee Ngeow
liber@darth.PGH.PA.US (Eric Liber) (11/27/89)
In article <43367@bu-cs.BU.EDU>, ngeow@bu-cs.BU.EDU (Yee Ngeow) writes: > I recently obtained a Quantumn Hard disk, model 520. Can anyone who > know the drive parameters let me know what they are? Specifically I need > to know: (Just fill in the blanks) > Cylinders : 512 Heads : 4 Format MFM/RLL : MFM Reduce write cyl: 256 Write precomp : 256 Error corr. bits: 11 - This is usually dependant on the controller used Step rate : I am not sure what you want here - most (all?) modern controllers will use buffered stepping so the actual rate the drive works at is irrelavant. However the drive is specified as being: Track to track : 10ms (12ms max) average : 45ms (49ms max) Full Stroke : 80ms (90ms max) average latency: 8.5ms Transfer rate 5.00Mbits / sec Capacity (unformated) 21.33MB Interface: ST506/412 I have used the 40 meg version (Q540) and it is a fine (if a little slow) drive. DEC uses them as the RD52a. One note of warning : This drive uses a tracking techinque known as embedded servo wedge. As such it reserves a small portion of the end of each track for a track positioning signal. Therefore, the controller electronics must be smart enough to format the drive in somewhat less than 360 degrees. MOST modern controllers (last 4 years?) can deal with this automatically. I have run into some that either were not capable of writing this way or required a specific bit to be set in a control register that was not automatically done by the low level format process. I only pass this along as a warning since it caught me by the a**. If you are using a standard MFM ST506/412 controller of relatively recent manufacture then you should have no problems. Good Luck Eric (the red baron) Liber
dougm@palomar.SanDiego.NCR.COM (Doug Marshall) (11/29/89)
In article <43367@bu-cs.BU.EDU> ngeow@cs.bu.edu (Yee Ngeow) writes: > > I recently obtained a Quantumn Hard disk, model 520. Can anyone who >know the drive parameters let me know what they are? Specifically I need >to know: (Just fill in the blanks) > >Cylinders : ** 512 >Heads : ** 4 >Format MFM/RLL : ** ? >Reduce write cyl: ** none >Write precomp : ** 256 >Error corr. bits: ** ? >Step rate : ** 7 According to the documentation that I have, this disk is ~ 20Mb. ---- Doug Marshall <Doug.Marshall@SanDiego.NCR.COM> +1 619 485 3494 <...!ncr-sd!palomar!dougm> "All of us is smarter than each of us!"