bforob@ubvmsb.cc.buffalo.edu (Robert Rothkopf) (06/28/91)
Hi. I just got hold of an old IBM/XT with two 5.25 low density drives. I'd like to add two new drives, perhaps a high density 3.5 and a high density 5.25 drive. Somehow, I remember hearing that the high density drives can't be used on the older machines. Could someone confirm this and indicate how high (and why) we can go with these older machines? Thanx a bunch, --Rob
burton@asdsun.larc.nasa.gov (John Burton) (06/28/91)
In article <81555@eerie.acsu.Buffalo.EDU> bforob@ubvmsb.cc.buffalo.edu writes: >Hi. I just got hold of an old IBM/XT with two 5.25 low density drives. I'd >like to add two new drives, perhaps a high density 3.5 and a high density 5.25 >drive. Somehow, I remember hearing that the high density drives can't be used >on the older machines. > >Could someone confirm this and indicate how high (and why) we can go with these >older machines? > >Thanx a bunch, > >--Rob Rob, You *can* install both the 5.25" 1.2mb drive and the 3.5" 1.44mb drive in an IBM-PC/XT. I've done it and I think mine is an even older version of the XT (*1* 5.25 low density full height drive and *1* 10mb full height hard disk - max 256kb on motherboard). There are two things you *must* have besides the disk drives...you *must* have a high density controller (one that *specifically* states that it will support 3.5" 1.44mb & 5.25" 1.2mb floppies on an XT class machine). The controller that came with your XT would *probably* not support the high density drives (assuming that you have an original equipment controller). These controllers are available from many places for < $50 (I purchased one from JDR micro devices that I *know* works, and I purchased one from CompuAdd that I haven't installed yet (for another machine)). The important thing is that these controllers have on-board BIOS that takes over from the motherboard BIOS when dealing with the floppies - the motherboard BIOS doesn't have a clue about high density drives... The other must is a current version of DOS (assuming you're using DOS). You need to have PC-DOS (or MS-DOS) ver 3.3 or later to support the high density drives, particularly the 1.44mb drive - I *think* the 1.2mb drive was supported in DOS3.2 or maybe even 3.1, but the 1.44 was not supported until the later version... best bet, call EggHead and get your $40 upgrade to MS-DOS 5.0 (unless they've sold out), that *definitely supports the high density drives...good luck... John +--------------------------------------------------------------------+ | John Burton | | G & A Technical Software | | jcburt@gatsibm.larc.nasa.gov | | jcburt@asdsun.larc.nasa.gov | | jcburt@cs.wm.edu | | | | Disclaimer: Hey, what can I say...These are *my* views, not those | | of anyone else, be they employer, school, or government| +--------------------------------------------------------------------+
wind@cellar.bae.bellcore.com (Wind Chen) (06/28/91)
To install 3.5" FDD and 5.25" HD FDD on IBM/XT, you will need to buy a new interface card. If you are interested, I have one for sale. Send me eMail for detail.