MFM/RLL data recovery

[Ryan Underwood]

On Tue, Apr 05, 2005 at 03:57:24PM -0500, cctalk-request at classiccmp.org wrote:
 
> Wait -- the Miniscribes are MFM, yes?  You should be testing them with the WD 
> controller, not the RLL controller.

No, they are RLL.  8438 are RLL variant of the 8425.  They ran for years
with the 27X controller in my family's XT :)

> Also, since you're testing on a 386, go into the 386's BIOS and make sure that 
> the 386 isn't trying to map something into the ROM address space that the 
> controllers are trying to use (ie see if it's possible to relocate the 386's 
> onboard IDE controller BIOS location, if it has one -- my Dell 316sx works like 
> this, for example... can also relocate video ROM location too).

This is a 386 clone board without any onboard peripherals.

> If you exhaust all options, send me the MFM drive -- I have a 100% working 
> WD1002 system set up right now with an ST-225 and could take a look at it for you.

I'll keep that in mind, thanks!

> Isn't that only a requirement of SCSI drives?  I certainly don't have any 
> terminators on my MFM/RLL drives...

These are terminating resistor packs which are located on the drive PCB,
not a terminator in the SCSI sense where it's plugged into the end of
the chain.  Also, I believe SCSI terminators are composed of
transistors, not resistors.

-- 
Ryan Underwood, <nemesis at icequake.net>