Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!uwvax!astroatc!nicmad!brown From: brown@nicmad.UUCP Newsgroups: net.micro.pc Subject: Re: Adding a 3rd Disk Drive to a PC Message-ID: <919@nicmad.UUCP> Date: Wed, 22-Oct-86 21:16:51 EDT Article-I.D.: nicmad.919 Posted: Wed Oct 22 21:16:51 1986 Date-Received: Thu, 23-Oct-86 02:53:02 EDT References: <636@watmum.UUCP> Reply-To: brown@nicmad.UUCP (Mr. Video) Distribution: na Organization: Nicolet Instrument Corp. Madison WI Lines: 36 In article <636@watmum.UUCP> smvorkoetter@watmum.UUCP (Stefan M. Vorkoetter) writes: > > >Does anyone know of any software difficulties with adding a third >floppy disk drive to a PC? I want to add a 720K drive and run under >DOS 2.10. How do I tell DOS the drive is there, and what format it >is? Thanks in advance. No problem. The XT I am using has two 20MB hard drives, two 1/2 height 5.25" floppies and two 3.5" floppies. If you have any hard disks, you will need to change all program references to particular drives, ie, C:. When you change the number of floppy drives attached switch from two to three or four, the first hard drive will start at D: or E:. That is why I set the switch to four floppies, even though I only had two attached at the time. [poster note: New BIOS XTs cannot have switch set to 4 and have the hard drive start at E:. New BIOS actually checks to see if drives are attached and adjusts accordingly (dumb)] All you need to do is provide power to the drive (used externally) and make the ribbon cable that goes from the 37 pin D floppy controller connector to the 34 pin floppy connectors. BTW, the 34 pin floppy cable connects to pins 4 through 37 of the D connector. Now, here is the part you are not going to like. PC-DOS 2.10 will not work with the 720K drives, ie, when formatted, you will only get 360K. You need to purchase PC-DOS 3.20 or get one of the new BIOS XTs. PC-DOS 3.20 has the device driver needed to run the 720K drives. Hope this helped a little bit. -- ihnp4------\ harvard-\ \ Mr. Video seismo!uwvax!nicmad!brown topaz-/ / decvax------/