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From: TOMIII@MTUS5.BITNET (Thomas Dwyer III)
Newsgroups: comp.sys.ibm.pc.programmer
Subject: Re: .SYS (device drivers) that are actually .EXEs?
Message-ID: <90187.102930TOMIII@MTUS5.BITNET>
Date: 6 Jul 90 15:29:30 GMT
References: <j8t1seef8@tmsoft.uucp> <141@qmsseq.imagen.com> <552@csource.oz.au> <142@qmsseq.imagen.com>
Organization: Computing Technology Services, Michigan Technological Univ.
Lines: 21

Just what *is* involved in loading a block driver and linking it into
the chain?  What about removing drivers?  Can I just set the previous
driver to point to the following one, and then free some memory?  One
more thing - suppose I want to install a ram disk, and have my autoexec
copy some files there.  How can I determine the device number (ie A=0,
B=1, etc) of the ramdisk?  No, I do not want to boot once and start
guessing letters until I find it, and then code that into the autoexec.
I want to determine the device number(s) independant of hard drive
partitions, switch settings, and the order of my config.sys file.

My solution was to patch the init routine of the ramdisk I use now to
save the device number passed to it by DOS.  Then I track down the
driver in memory, and grab the number from a predetermined offset from
the device header.  Isn't there a better method that does not require
me to patch my driver(s)?

Thanks,
Thomas Dwyer III                            TOMIII   @ MTUS5.BITNET
Network Programmer                          DWYERIII @ MTUS5.BITNET
Computing Technology Services
Michigan Technological University