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From: w8sdz@rigel.acs.oakland.edu (Keith Petersen)
Newsgroups: comp.binaries.ibm.pc.d
Subject: Re: Need driver for LARGE RAM disk
Summary: Maybe sector size is the key to making ramdrive.sys work
Keywords: RAM Disk
Message-ID: <6602@vela.acs.oakland.edu>
Date: 27 May 91 20:39:52 GMT
References: <468@txsil.lonestar.org> <1991May27.043524.20211@uwasa.fi>
Sender: news@vela.acs.oakland.edu
Reply-To: w8sdz@wsmr-simtel20.army.mil
Organization: The SIMTEL20 Archives
Lines: 35

[Some users say Ramdrive.sys doesn't work for very large ramdisks]

If you use MicroSoft's Ramdrive.sys the commands are:

device=ramdrive.sys [disksize (in Kbytes)] [sectorsize] [entries] /e
   or
device=ramdrive.sys [disksize (in Kbytes)] [sectorsize] [entries] /a

Example:

device=ramdrive.sys 1024 512 256 /e

This makes a 1 megabyte ramdisk, in extended memory, which has 512
byte sectors with 256 directory entries maximum in the root directory.
For very large ramdisks you may run into limitations if you use sector
sizes smaller than 512 because of the number of bits available in the
FAT for each entry.  If 512 doesn't work, try 1024. (1024 is the
maximum allowed).

The /e option uses extended (above one meg) memory.  If you use this
option, the ramdrive.sys entry should appear before any entry for
an extended memory manager such as qemm386.sys, etc.  Otherwise
qemm386.sys will grab all available extended memory to be used as
XMS and expanded memory.

The /a option lets you use LIM expanded memory for the RAM drive.
The book says that if you have extended memory the /e option is
preferred.

Keith
--
Keith Petersen
Maintainer of the MSDOS, MISC and CP/M archives at SIMTEL20 [192.88.110.20]
Internet: w8sdz@WSMR-SIMTEL20.Army.Mil    or     w8sdz@vela.acs.oakland.edu
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