ST-238R and ST-225, likely controller?

Randy McLaughlin cctalk at
Thu Mar 10 13:47:22 CST 2005

From: "Ryan Underwood" <nemesis-lists at>
Sent: Thursday, March 10, 2005 12:17 PM
> Hi,
> A friend has a ST-238R and ST-225 that came out of his XT long ago.
> We're trying to figure out what the most likely controller that was
> being used in the original machine so we can recover the data.  It must
> have been 8-bit and support RLL.  The best guess I can come up with is
> the WD 27X (which I used to have).  Anyone else have a good guess?
> I think the ST-225 came with the machine and then the ST-238R was
> installed as part of a kit.  So whatever controllers were usually sold
> with those as a kit (i.e. from Dirt Cheap or a refurbisher) would be a
> likely candidate too.  For example, my 27X came with a Miniscribe 8438
> kit from a refurbisher.
> Thanks,
> -- 
> Ryan Underwood, <nemesis at>

There were lots of different controllers for the PC/XT.  None were data 
comptatable with the other.

The 238 came out later in the picture as far as the PC is concerned.  But I 
personally used at least three 8 bit RLL controllers (WD, Adaptec, and 
Seagate) there were many others.

If you changed controllers you had to do a low level format.

If you have some different controllers you will need to do trial and error 
to find the right one(s).  I recomend write protecting the drives by either 
cutting the write gate line in the cable or putting a piece of tape over the 

It is also possible that the drives were both formatted MFM.  The 225 & 238 
were the same drive, I never knew of any real difference other than the 
label.  The MFM & RLL are different encode techniques, RLL requires a very 
stable spindle speed beyond that required for MFM.


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