MfM and Dll

I picked up an HDD made for the Atari ST by ICD. It is a shoebox form and has space and connectors for 2 HDs. The highly proprietory HD interface by Atari (ATASCI ?) is usually directly converted to SCSI in most newer HD adapter interfaces for STs. In the Atari and ICD HDs the DMA output was converted to SCSI by an ICD card and then to MFM or DLL. via an Adaptec 4004 (MFM) or 4070(RLL) controller. This one has an Adaptec 4070. The 1 drive present is a Miniscribe 3834P . I understand that some MFM drives could be coded by a RLL controller if they were fast enough, etc. I have an ST4096, which according to the specs I have seen is an 80 meg MFM , as well as several other smaller MFM HDs. According to a spec sheet the 4096 would work with Perstor Systems ADRT controllers to double the storage which would seem to indicate it was of high enough speed and quality to stand the tighter coding.. Anyone know if this is also true with an RLL controller or what MFM drives do work with RLL ? ciao larry lwalker(a)interlog.com