Brian, I made a real simple boot disk with a RAM drive. I been testing it as a floppy image in virtualPC and it works fine.
Haven't got aroung to trying it in grub or from an ISO yet.
I made a bootable floppy image with these files on it:
Io.sys
Msdos.sys
Himem.sys
Findramd.exe
Ramdrive.sys
Setramd.bat
Or you can take a windows98 SE floppy image and remove everything else.
My config.sys is:
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device=himem.sys
files=10
buffers=10
dos=high,umb
stacks=9,256
devicehigh=ramdrive.sys /E 10240
lastdrive=z
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You can see I set the RAM drive for 10MB, you can change that value up to a max of 32MB. Its set in KB's with 1024=1MB
My Autoexec.bat is:
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@ECHO OFF
set EXPAND=YES
SET DIRCMD=/O:N
set LglDrv=27 * 26 Z 25 Y 24 X 23 W 22 V 21 U 20 T 19 S 18 R 17 Q 16 P 15
set LglDrv=%LglDrv% O 14 N 13 M 12 L 11 K 10 J 9 I 8 H 7 G 6 F 5 E 4 D 3 C
cls
call setramd.bat %LglDrv%
set temp=%RAMD%:\
set tmp=%RAMD%:\
path=%RAMD%:\;a:
echo Your RAM Drive is Letter %RAMD%
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I made it display the drive letter of the RAM drive but I don't know if it can be set as a letter that will work on every system like you did with the CD-ROm drive letter.
It always takes the first availible drive letter and it's going to be different on every system depending on how many "DOS Visible" partitions are present.
However, like I said before, the variable %RAMD% can be used for any commands. Just remember to add a colon to the end if your changing drives:
%RAMD%:
A couple suggestions,
You don't want "more.com" to be simply copied from the A drive to the RAM drive because since the path is set for both drives if you run the command it may run more.com from the A drive instead of the RAM drive.
You might want to make a subfolder to hold it and any other files and then copy those to the RAM drive:
copy A:\MyFiles\*.* %RAMD%:\
If you have a lot of files, it sometimes is a little annoying to see all those files being copied.
Another option is to make all the files into a .cab file and extract them into the RAM drive just like the windows 98 boot disk does with the "ebd.cab"
extract.exe /y /e /l %RAMD%: MyFiles.cab > NUL
(needs extract.exe for that)
I don't think it applies, but if you need to use more than one floppy to load everything you can also copy io.sys to the ram drive and then in the autoexec.bat make a line:
set comspec=%RAMD%:\command.com
Then you can be switching floppies or CD's and still be able to run DOS out of the RAM drive.
Dave
Edit- You really don't need these lines:
set EXPAND=YES
SET DIRCMD=/O:N
I just noticed I left them on from the standard boot disk. You don't need the expand command, even if your using extract.exe and they way the directories are listed may not matter.