sph@logitek.co.uk (Stephen Hope) (03/11/91)
tmurphy%peruvian.utah.edu@cs.utah.edu (Thomas Murphy) writes: >>I have a Microlis 1335 (71-Meg MFM) HD and I want to get a RLL/ ERLcard. >>Is this drive capable of being formatted w/ a RLL card? >>A "mail-order-tech" claimed any MFM drive can be formatted to RLL but it >>might by unstable -- if the drive even works at all. >>Shaun Wetzstei -- NU158739@NDSUVM1.BITNET >Don't do it!!!! RLL drives must meet different specs and though it >might format you will not have a trustworthy disc...there are some >other "increased density" type cards out that may work though... There is a rule of thumb provided by an Adaptec distributor rep. here in the U.K. 4 years ago.. (private opinion, backed by Adaptec testing): There are 2 types of drive which can be safely used with RLL, certified drives and MFM drives which use plated media. Oxide coated media in MFM drives can give problems. This info was given to us when RLL was a "new" idea with ST506 interface drives.. eventually we decided that this was a risk which we didnt need to take, so we didn't (Private opinion ONLY) About 6 months later, 3Com started using Priam MFM 70Mb drives with their dedicated network servers, with an Adaptec SCSI to RLL controller. This seemed to be as reliable as the original setup (with MFM). HOWEVER, other info I have seen quotes a reduction in reliability on some drives of 10X for media related errors - I havent got this info any more so cannot quote the source. This seems reasonable, given that RLL requires much tighter timing tolerances from the drive / data separator, especially as MFM drives are not designed with RLL in mind (or werent 4 years ago)