China DOS Union

In batch files, we always define the drive letters for the memory disk and CD-ROM first, and then use them. For example, Set ramdrive= and Set cdrom=, then use Xmsdskt to create the memory disk, load the Vide-cdd.sys CD-ROM driver in Config.sys, load the shsucdx.exe CD-ROM extension driver in Autoexec.bat, and then use Findramd and Findcd to find the drive letters of the memory disk and CD-ROM, setting the path as: Path %ramdrive%\;%cdrom%\。But in some boot disks, %ramdrive% and %cdrom% have to be followed by a colon (, that is, like this: Path %ramdrive%:\;%cdorm%。
My question is: when exactly should there be a colon (, and when should there not be a colon (?

It depends on the program used to find the drive letter! Wengier's findcd.exe program automatically stores the drive letter and colon in the %cdrom% environment variable. But Win98's findramd batch program only stores the virtual disk drive letter in %ramdrive%, without the colon, so the path line has to add the colon. You should know that these %xxxx% environment variables are essentially just strings. Whenever a command containing environment variables is executed, DOS automatically "restores" the environment variables into strings. For example: when executing Path %ramdrive%\;%cdrom%, if the virtual disk drive letter is G: and the CD-ROM is H:, then the command is actually executing path g:\;h:

Win98's one is %ramd%, and it does not include the colon. Whether to add %cdrom% in path is up to you. I just don't like adding a: and %cdrom% to path, because if the required command is not in the ramdisk, it will automatically go to a: and cdrom to look for it, which instead reduces system efficiency.

With or without the colon is not the same. Suppose you use Finfcd to find the CD-ROM drive letter and it is drive G. If you do not include the colon, then Path %cdrom%\ becomes Path G\ , and that won't work; on the other hand, if you include the colon, Path %cdrom%:\ becomes Path G:\, and that will work.

Why not use shsucdx.exe to specify the drive letter? I just set the CD to z:\

Of course you can specify the CD-ROM drive letter and the memory disk drive letter, but I prefer my way.