home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.sys.ibm.pc.hardware
- Path: sparky!uunet!clarkson!news
- From: faruque@sun.soe.clarkson.edu (Abdullah Faruque,334CH,3752,2654247)
- Subject: Re: IDE HD and MFM (XT) HD in the same AT ?
- Message-ID: <1992Aug21.235526.18472@news.clarkson.edu>
- Sender: news@news.clarkson.edu
- Nntp-Posting-Host: sun.soe.clarkson.edu
- Organization: Clarkson University
- References: <jmh.714382322@tko.vtt.fi>
- Date: Fri, 21 Aug 1992 23:55:26 GMT
- Lines: 85
-
- From article <jmh.714382322@tko.vtt.fi>, by jmh@tko.vtt.fi (Michael Hasemann):
- > Hi Netters,
- > I would like to use an IDE HD and a XT HD in the same AT.
- >
- > Is that possible ?
- > Any hints appreciated.
- >
- > Regards Michael
-
- Yes, it is possible to run both IDE and MFM/RLL drives together.
- Currently I am using a 80 meg IDE (Maxtor 7080A) and a 65 meg RLL
- (Seagate ST277R-1) drive together in a 386 machine. I have seen this
- question several times, so I compiled the following summary about this
- matter. There are three ways it can be done:
-
- 1. You need the right MFM/RLL controller card which can be set at the
- secondary hard drive port address with the onboard BIOS enable. Also
- the onboard BIOS must support hard drive at the secondary port
- address. The only 16-bit MFM/RLL card (as far as I found) that
- fulfills those requirements is the Seagate ST21/22M (MFM model) or
- ST21/22R (RLL model). Although most other RLL cards (I have tried
- Wester Digital, Adaptec and DTC) in the market do have an onboard
- BIOS and jumpers to set it at a secondary port address, but they will
- not work as a secondary controller. Probably the onboard BIOS of
- those cards can not support hard drives at the secondary port address.
- This problem may be solved by loading a device driver through the
- operating system, but this kind of device driver is not available (as
- far as I know) from the manufacturer or from any ftp sites. So, you
- may have to write one and which may not worth your time and energy.
-
- So, get a ST21/22M or ST21/22R controller card and you are all set.
- Currently I am using a ST21/22R in my system. It runs without any
- problem with DOS 5.0, WIN 3.1. The following are some points that need
- to be considered while using IDE and MFM/RLL together.
-
- (i) If you already own a MFM/RLL drive (which is sitting around and
- collecting dust) then you just need a ST21/22 controller (they are
- around $45 new) and get some extra space. If you have to buy a MFM/RLL
- drive also, then probably it is not worth, instead buy a second IDE
- drive (which will be more cost effective).
-
- (ii) The onboard BIOS of the MFM/RLL card takes some memory space from
- the UMB (memory between 640K and 1meg). So, you have to configure your
- memory manager (EMM386, QEMM etc.) to exclude that area if your memory
- manager unable to detect ROM BIOS of the controller card to avoid
- software conflicts.
-
- (iii) You have to disable the floppy part of the ST22M or ST22R
- when using it as a secondary controller. There are jumpers to disable
- the floppy part. ST21M or ST21R does not have any floppy support.
- Your floppy drive should be run by the IDE host adaptor or a floppy
- only controller card at the primary floppy drive port address.
-
- (iv) You can only use one MFM/RLL drive (as D: drive) in conjunction
- with only one existing IDE drive (the C: drive). Although the MFM/RLL
- controller supports two hard drive but that will work only in the
- stand alone mode. The onboard BIOS of ST21/22 is not yet capable of
- recognizing any drive beyond C: and D: drive.
-
- 2. The second method is to use an IDE host adaptor card that can
- co-exist with other MFM/RLL controllers. I have seen these kind of
- product advertised in Computer shopper, they are expensive too. I
- never used one, so I can not tell much about it. If somebody has any
- experience, then I would like to hear about it.
-
- 3. The third method is to use a 8-bit XT type MFM/RLL controller card.
- Some of these type of cards (not all of them) can be configured as
- secondary controller and can co-exist with other types of primary
- controller cards. I will not recommend this method, because you will
- get poor performance with an 8-bit card in an AT type machine.
-
- I would like to here if there is any other possible ways of doing this.
-
- -Faruque
- Email: faruque@sun.soe.clarkson.edu
-
-
-
-
-
-
-
-
-
-
-