[comp.sys.ibm.pc.misc] Re : RLL Interface

cy5@cunixa.cc.columbia.edu (Conway Yee) (09/25/90)

I posted a message which is slightly in error.  The drive types for an
RLL drive do not exist on a IBM AT.  Thus, disk manager is required to
access the full potential of the drive.  Alternative solutions is to
use a user defined drive which some ROMs support.  Below is the email
message I recieved.

					Conway Yee
========================================================

From sigma@pawl.rpi.edu Thu Sep 20 20:53:08 1990
>In article <1403@atlas.tegra.COM> vail@tegra.COM (Johnathan Vail) writes:
>>
>>I was given a RLL controller (Western Digital) for an AT.  Does it
>>require special software and drivers or is it treated the same as a
>>"normal" MFM controller?

>If you have an RLL drive, just connect the sucker up and off you go!

NO - he wants to put it in an AT, which has CMOS setup, which leads to problems
with which drive types his ROM knows, which are probably all MFM drives, so
if he just hooks it up and auto-configures, he loses 50% or more of his
drive capacity right there!

Solutions: Disk Manager, new ROM, drive type 47.

					Conway Yee, N2JWQ
email : yee@ming.mipg.upenn.edu (preferred)   USnail: 231 S. Melville St.
	cy5@cunixa.cc.columbia.edu                    Philadelphia, Pa 19139
	yee@bnlx26.nsls.bnl.gov (never checked)	      (215) 386-1312

c60c-1gd@e260-3c.berkeley.edu (Joon Song) (09/26/90)

>>>I was given a RLL controller (Western Digital) for an AT.  Does it
>>>require special software and drivers or is it treated the same as a
>>>"normal" MFM controller?
>
>>If you have an RLL drive, just connect the sucker up and off you go!
>
>NO - he wants to put it in an AT, which has CMOS setup, which leads to problems
>with which drive types his ROM knows, which are probably all MFM drives, so
>if he just hooks it up and auto-configures, he loses 50% or more of his
>drive capacity right there!
>
>Solutions: Disk Manager, new ROM, drive type 47.

Western Digital RLL controllers have RLL drive types in ROM.  However, they
do not match MFM drive types in the system ROM.  For example a 1024 cylinder,
9 head drive is drive type 35 on the system ROM, but drive type 19 on the RLL
controller ROM.  So, disk manager is not necessary.  You just need to find
the correct drive type for the RLL drive.  There are several programs
available that will let you do this, ex. CMOSER.