Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!srcsip!orion!rogers From: rogers@SRC.Honeywell.COM (Brynn Rogers) Newsgroups: comp.sys.ibm.pc Subject: Re: RLL controllers with MFM drives Message-ID: <35883@srcsip.UUCP> Date: 22 Oct 89 15:21:39 GMT References: <2546@bingvaxu.cc.binghamton.edu> <4265@ncsuvx.ncsu.edu> Sender: news@src.honeywell.COM Reply-To: rogers@src.honeywell.com (Brynn Rogers) Organization: Honeywell Systems & Research Center Lines: 66 In article <4265@ncsuvx.ncsu.edu> unkydave@shumv1.ncsu.edu (David Bank) writes: > DISCLAIMER: This is ** NOT ** a flame! > Sure, Ken. Go for it. Hook that MFM (i.e. NOT RLL-Rated) drive up to >that RLL controller, format it, and instant 50% more drive room. You >CAN do it. It'll even format. > If you're lucky, it might even hold data for a month before it starts >developing amnesia. > RLL is a MUCH more demanding format and less tolerant of errors. MFM >drives are not RLL rated for a very good reason -- they can't deliver >the performance RLL-controllers demand. They are very simply not >engineered for the rigors of RLL usage. > So...you CAN do what you want. But you had better hope and pray >and sacrafice virgins to Mammon or that drive WILL crash. Not might. >WILL. It is only a matter of time before you get "Disk Boot Error" >or "Invalid Drive Specification" or some similar, sinister, error >message. > KIDDIES! Do NOT TRY THIS AT HOME!!! > If a drive is not SPECIFICALLY RLL-Rated by its manufacturer, >do NOT try hooking it to an RLL controller to boost storage. You >are playing Russian Roulette with your data and there is a VERY high >probability that you will lose everything. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Dave's blanket statement > If you want the space THAT badly, go out and buy yourself an >RLL-rated drive! >Unky Dave >unkydave@shumv1.ncsu.edu I think that this is a little overboard. (or Dave sells drives) One Manufacturer in particular (Maxtor) does not rate many of it's drives RLL and yet I have had one running for over a month at almost double its rated capacity. (A XT-1140 formats to 120 Meg MFM, I formatted it as a XT-1240 RLL drive and got 204 Meg) I talked to no less than six people who have been running MFM-rated Maxtors as RLL drives and not one of them had a single complaint (and they had a aggregate total time of more than ten years) As I understand it, Maxtor uses plated media, and I have heard that the main requirement for RLL is plated media. I talked with the tech support people at maxtor and they said 'the XT-1140 is not RLL rated', but in another sentence said 'Many of our customers run our drives RLL with no problem' (But I had to drag it out of them.) I don't doubt that taking a low end MFM drive and running it RLL can give problems, But I strongly object to the blanket statement that you CANNOT use a MFM drive with a RLL controller. Some MFM drives will work RLL, some won't. About the only way to be sure is to try it (But keep everthing backed up, and keep your MFM controller) After getting an informal poll of people that use your drive RLL. Brynn Brynn Rogers Honeywell S&RC rogers@src.honeywell.com home 612 874-7737