[comp.sys.ibm.pc.hardware] RLL and sector remapping revisited

jwbirdsa@amc-gw.amc.com (James Birdsall) (10/09/90)

   I recently posted about my misadventures with the Mitsubishi MR535 drive
in RLL mode and the 1024-cylinder limit. I seem to have mostly generated
controversy on whether an odd number of heads is possible...

   So I'm going to ask again: I have a Western Digital WD1002A-27X RLL
controller. This is an 8-bit XT controller running in an XT. I have no docs
for it.
   I have been told that some WD controllers can disable the 26-to-17
sector remapping. Can this one do that? What are the pitfalls of doing so?
Will I be required to run Disk Manager on all my drives?
   Or, can I get a BIOS upgrade which will allow disabling the remapping?
   Or, should I get another controller?

-- 
---
James W. Birdsall        jwbirdsa@amc.com         71261.1731@compuserve.com
          Compu$erve: 71261,1731            GEnie: J.BIRDSALL2
For it is the doom of men that they forget. -- Merlin

cgordon@vpnet.chi.il.us (Gordon Hlavenka) (10/10/90)

>   So I'm going to ask again: I have a Western Digital WD1002A-27X RLL
>controller. This is an 8-bit XT controller running in an XT. I have no docs
>for it.
>   I have been told that some WD controllers can disable the 26-to-17
>sector remapping. Can this one do that? What are the pitfalls of doing so?

You most certainly can do this.  I have that controller, running in non-
translation mode, in an XT.  There is one jumper to move, I just don't
remember which one it was.

You can get a manual just by calling WD at (800) 832-8176 and asking for it.
 That's how I got my manual (which I promptly lost, or I'd look up the
jumper for you!).

The pitfalls would be that some BIOSs and/or DOSs don't like 26 sector
disks.  I don't know why this is, but if it works on your machine (it does
on mine) you should be OK.

>Will I be required to run Disk Manager on all my drives?

You should only need to run DM on the drives that need it (i.e. >32MB)

-----------------------------------------------------
Gordon S. Hlavenka            cgordon@vpnet.chi.il.us
Disclaimer:                Yeah, I said it.  So what?