w8sdz@WSMR-SIMTEL20.ARMY.MIL (Keith Petersen) (02/26/89)
kluge%lan.informatik.tu-muenchen.dbp.de@relay.cs.net writes:
In DOS 3.30 Microsoft put in a new config.sys variable named
DRIVPARM. With this variable, it is possible to change the
default configuration of the built-in device drivers for
floppy disk I/O. DRIVPARM does the same thing DEVICE=DRIVER.SYS
does, except that it does not install a new driver but changes
the configuration tables of the drivers built-in. DRIVPARM
also uses the same syntax that DRIVER.SYS uses.
This variable was embedded in all OEM versions of MS-DOS 3.30
and also in IBM's PC-DOS 3.30 (However, IBM did not mention the
command in its documentary). A Microsoft representative ensured
me this, and it can be proved by using DEBUG: debug ibmbio.com
and s 100 ffff 'DRIVPARM' will reveal its presence in the parse
table.
But due to a bug in Microsoft's DOS 3.30 this variable could not
be accessed by the user. Microsoft had already delivered all its
OEMs before the bug was detected. Microsoft soon released a patch
that would cure this bug. This patch was sent to all Microsoft's
OEMs, *including* IBM, as a Microsoft representative told me.
Other manufacturers did correct the bug (Hewlett-Packard did it)
and documented the new feature. However, IBM seems not to have
done it. The new feature isn't documented anywhere (nor does any
IBM representative seem to know of it) and IBM sells the version
with the bug.
The fix for this is described in file pd1:<msdos.sysutl>DRIVPARM.ARC
which is available from Simtel20. The file gives simple directions on
how to make the patch with DEBUG and how to use the patched DRIVPARM
in your CONFIG.SYS file.
--Keith Petersen
Maintainer of the CP/M & MSDOS archives at wsmr-simtel20.army.mil [26.0.0.74]
DDN: w8sdz@wsmr-simtel20.army.mil
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