lee@gdc.portal.com (Seng-Poh Lee, Gen DataComm, +1 203 758-1811) (03/11/91)
Hi, I know this can be done, I just want to know from people that have done it how reliable it is. I'm talking about formating an MFM drive with a RLL controller. I have an ultra reliable Hitachi MFM drive that I want to format in RLL format. I know it has very good margins so I would expect to to be reliable. I need more disk space and this seems the cheapest way to go, if it is reliable. Does anyone have long term reliability results regarding this? Thanks ----- Seng-Poh Lee Work: lee@gdc.portal.com Technology Center ...!uunet!portal!gdc!lee General DataComm Ind. Inc. Home: lee%splee.uucp@hsi.com ...!uunet!hsi!splee!lee
kgallagh@digi.lonestar.org (Kevin Gallagher) (03/14/91)
In article <6830@gdc.portal.com> lee@gdc.portal.com (Seng-Poh Lee, Gen DataComm, +1 203 758-1811) writes: > >I know this can be done, I just want to know from people that have done it >how reliable it is. > >I'm talking about formating an MFM drive with a RLL controller. I have a MiniScribe 40 Meg, Model 3650. It is sold as a MFM drive. I installed it on 12/9/88. I attached it to an Adaptec ACB-2072, which is an XT RRL controller. (There is also a corresponding AT version of this controller.) It was my understanding, at the time, that the platters inside this drive were identical to those MiniScribe used in its RLL certified drives. So I took a gamble that the drive would be able to handle RLL. The specs state that the drive has 6 heads with 809 cylinders, with a park zone on cylinder 852. I used the Adaptec low level format program in the firmware to format the drive into one large partition, requesting it format 809 cylinders. When the low level format and verify completed, it encountered NO track failures, so it did not use ANY of the spare cylinders above 809. I decided to re-do the low-level format and specified 840 cylinders. This format and verify completed without a problem. I then used FDISK from PC DOS 3.3 to partition the drive into two 32 Meg partitions. I have about 40 Meg of software and data installed on the drive, at the present time. My PC get used just about every day. I have had over two years of trouble-free operation. The only maintenance I do on the drive is to run Spinrite two or three times a year. During the past year or so on the net, this topic comes up every now and then. Some people reported serious problems when they formatted some brands of MFM drives with RLL. While others reported no problems with other brands. Good Luck! -- ---------------------------------------------------------------------------- Kevin Gallagher kgallagh@digi.lonestar.org OR ...!uunet!digi!kgallagh DSC Communications Corporation Addr: MS 152, 1000 Coit Rd, Plano, TX 75075 ----------------------------------------------------------------------------
slootman@dri.nl (Paul Slootman) (03/16/91)
In article <1991Mar14.041558.24419@digi.lonestar.org> kgallagh@digi.lonestar.org (Kevin Gallagher) writes: >>I'm talking about formating an MFM drive with a RLL controller. [some stuff deleted] > >I have a MiniScribe 40 Meg, Model 3650. It is sold as a MFM drive. I >installed it on 12/9/88. I attached it to an Adaptec ACB-2072, which is an XT >RRL controller. (There is also a corresponding AT version of this controller.) I have an Adaptec 2372, an AT RLL controller, also with a MiniScribe 3650, and additionally a Micropolis 1324 51 Meg MFM disk. >The specs state that the drive has 6 heads with 809 cylinders, with a park >zone on cylinder 852. [some stuff deleted] >did not use ANY of the spare cylinders above 809. I decided to re-do the >low-level format and specified 840 cylinders. This format and verify >completed without a problem. I then used FDISK from PC DOS 3.3 to partition I also use up to cylinder 840 (that's the way it was prepared when I bought the machine). > >My PC get used just about every day. I have had over two years of >trouble-free operation. The only maintenance I do on the drive is to run >Spinrite two or three times a year. We have 5 of these machines, and they're about 3 years old. Two of those have had a second disk added after about one year. The only trouble we have had is that in those two, the disks seem to overheat (if you look at the PCB, there is a place, I think where the head stepper motor control is, which becomes a bit brown :-( ). Perhaps two disks heat up the environment inside the PC too much? Switching the machine off for some time, turning it back on, quickly making a backup (which is of course done regularly :-) saved the data. BTW, reformatting the disk with MFM didn't make any difference, apparently it slowly dies. The Micropolis disk runs without any trouble at all (giving me 78 Meg). BTW, Maxtor XT1140's are great too - 230 Meg instead of 112 Meg! (Don't forget the 220 tracks Maxtor forgot to tell us about [flame preventer: I know, they're not certified or anything, use at your own risk, only if you're not worried about the data, etc. I use it for /tmp]) Summary: If the formatting doesn't give any trouble (or only a couple of extra sectors), things will probably be ok. Paul. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= : slootman@dri.nl : Don't hit the keys so hard, : : ...!hp4nl!dri500!slootman : it hurts : =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=