Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!apple!oliveb!pyramid!weitek!hemingway!robert From: robert@hemingway.WEITEK.COM (Robert Plamondon) Newsgroups: comp.sys.ibm.pc Subject: Re: Disk Driver Formatting in Message-ID: <799@hemingway.WEITEK.COM> Date: 29 Sep 89 20:00:22 GMT References: <89090607413782@masnet.uucp> <14789@netnews.upenn.edu> Reply-To: robert@hemingway.WEITEK.COM (Robert Plamondon) Organization: WEITEK, Sunnyvale CA Lines: 25 >> 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. Typing control-C will cause it to flush these buffers, at least in DOS 3.3. A different BIOS or an installable device driver will probably fix the problem. -- Robert -- Robert Plamondon robert@weitek.COM "No Toon can resist the old 'Shave and a Hair-Cut'"