[comp.sys.ibm.pc.hardware] Moving Command.Com into a RAMdrive in Tandy 1400HD

RFM@psuvm.psu.edu (03/01/91)

   I recently put out a request for info about how to move
Command.Com out into a RAMdrive on my portable (Tandy 1400HD)
to speed up thru-put. The Tandy 1400 has 128k of extra memory
that is neither extended nor expanded memory (What do you call
this kind of xtra mem???). This xtra mem seems to be useable only
for volatile storage of files in a RAM drive configuration.
   Several helpful folks responded, and I am summarizing their
responses/synthesizing them into the statements that I have put into
my AUTOEXEC.BAT and CONFIG.SYS files to move COMMAND.COM.
Some comments about general applicability also are included.

1. IN CONFIG.SYS:

      - Enter a line containing the device driver to create a RAMdrive.

      -- In my case (Tandy 1400, DOS 3.3), the line reads:

         DEVICE = RAMDRIVE.SYS

      -- Other systems may need to use VDISK, etc., as appropriate.
      -- In my Tandy 1400HD case, the system assigns a logical drive
         designation of "D" by default.

2. IN AUTOEXEC.BAT:

      - Enter two lines, as follows:

        COPY C:\COMMAND.COM D:\COMMAND.COM

        SET COMSPEC=D:\COMMAND.COM

      -- The COPY line contains overkill with the 2nd Command.Com
         entry, but I'm uptight when I'm trying something new.


   I followed these steps, and everything seems to work like a
champ. Let me tell you what seems to be happening now, in one
obvious case.

   Watch your system when you do a "DIR" command. DIR seems to execute
in two steps. At step 1, you'll see your hard/floppy drive spin a little
bit while the system is reading Command.Com. At step 2, the drive spins
again as the system reads the drive's directory, its FAT tables
(I think),  and then prints the directory listing.

   With Command.Com in a RAM drive, the Step 1 in this process now
seems "invisible." Step 2 seems to kick in right away. The drive
starts spinng & listing the directory. Time savings seems to be in
the range of 1-2 seconds max, but it sure seems to be *faster*!

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My thanks to the following people for input:

Nate Lisko  <nate@neutron.lcs.mit.edu>
Nick FitzGerald, CSC, Uni. of Canterbury, NZ
 <CCTR132@csc.canterbury.ac.nz>
Richard Brittain - VOS hacker <richard@calvin.ee.cornell.edu>
Brian K. W. Hook <jdb@reef.cis.ufl.edu>
Nirad Sharma <exnirad@brolga.cc.uq.oz.au>
William Epperly <epperly@cs.odu.edu>
& any/all others I (inadvertently) omitted.

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   Does anyone out in <NetLand> have any suggestions about anything
else I could/should put out on that RAMdrive to enhance thruput?
I'm waiting for a program that *may* make my machine think that 64k
of that RAMdrive memory is 3.2 expanded memory. If this works, I
can create a CACHE out there, and that should do wonders for my
hard drive I/O.
   But even with a Cache in place, I'll still have 30+k of RAMdrive
memory to play with. Any/all suggestions will be appreciated.


Bob Munzenrider, Penn State - Harrisburg <rfm@psuvm.edu>

Mini-Hacker <Diminutive>

DoD # 197
SoB # 9