Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 (Tek) 9/26/83; site mako.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!zehntel!tektronix!orca!mako!glenm From: glenm@mako.UUCP (Glen McCluskey) Newsgroups: net.micro.pc Subject: device driver question Message-ID: <380@mako.UUCP> Date: Wed, 28-Nov-84 22:15:26 EST Article-I.D.: mako.380 Posted: Wed Nov 28 22:15:26 1984 Date-Received: Fri, 30-Nov-84 08:15:45 EST Organization: Tektronix, Wilsonville OR Lines: 25 A friend of mine has been working on developing a system that will allow a PC to treat a file on a VAX (running VMS) as a disk drive. This is accomplished by writing a server for the VAX and a device driver for the PC that knows how to talk to the VAX server through the serial port. There is also a utility program that runs on the PC that can be used to tell the VAX to create, delete, or select files to use as virtual disks. The problem is this: it would be nice if the file on the VAX did not have to be a hardwired size -- it is desirable to let it be X number of blocks, where X is completely up to the user. MSDOS, however, will not recognize the size specified in the boot block -- it gets loaded into memory whenever MSDOS calls the driver with the BUILD_BPB instruction, but the new size is ignored in subsequent DIR and CHKDSK commands. MSDOS is obviously capable of changing dynamically -- one can put a SSSD disk into a drive and MSDOS will recognize it and won't keep thinking there is a DSDD disk there -- but how can a device driver force the new size to be recognized? Glen McCluskey ..tektronix!mako!glenm