Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!uakari.primate.wisc.edu!gem.mps.ohio-state.edu!apple!usc!srhqla!nrcvax!rick From: rick@NRC.COM (Rick Wagner) Newsgroups: comp.sys.ibm.pc Subject: Re: Disk Driver Formatting in Message-ID: <364@nrcvax.NRC.COM> Date: 2 Oct 89 18:52:46 GMT References: <799@hemingway.WEITEK.COM> Reply-To: rick@nrcvax.UUCP (Rick Wagner) Organization: Network Research Corp., Oxnard CA Lines: 30 In article <799@hemingway.WEITEK.COM> robert@hemingway.WEITEK.COM (Robert Plamondon) writes: >>> I have a 3.5 " disk drive that can read 720K and 1.44M diskettes. It >>>is installed as the drive A: on my system. When I start the system, the >>>first diskette I read in this drive via aDIR command will have the >>>proper directory, but any other diskette read later will give me the >>>SAME directory as the first one, even if it's another. It seems that DOS >>>cannot re-read the FAT and DIR sectors. The diskettes I tried are both >>>formatted in DOS 3.3 and DOS 4.01. . . . . > >DOS (or the BIOS) expects the diskette drives to have a "READY" signal >that indicates whether the diskette has been replaced. If it expects >this signal from a drive that doesn't provide it, it thinks that it >still has the original disk in its drive, and uses the copy of the >directory and FAT in RAM, rather than reading it from the floppy >again. Most of the 3.5" drives do supply a "disk change" line. What I have found is alot of the drives are shipped with this option disabled. The drives I have seen (Teacs, I think), have a jumper on the board where the ribbon cable connects to the drive, which enables this signal. Check your drive documents, and see if this is the case with your drive. -rick -- =============================================================================== Rick Wagner Network Research Corp. rick@nrc.com rick@nrcvax.UUCP 2380 North Rose Ave. (805) 485-2700 FAX: (805) 485-8204 Oxnard, CA 93030 Don't hate yourself in the morning, sleep 'till noon.