II.1.4 DOS Environment
To specify a search path for include files, an optional environment variable ASEM51INC can be defined:
<path> may be any number of directories separated by ';' characters. Be sure that the whole definition doesn't contain any blanks or tabs! If ASEM51INC is defined, the assembler searches the specified <path> for include files that can neither be found in the working directory, nor in the search path specified with the /INCLUDES option. The <path> directories will be searched from left to right.
1.) SET ASEM51INC=C:\ASEM51\MCU;D:\MICROS\MCS51\INCLIf include files can neither be found in the working directory, nor in the /INCLUDES path (if specified), the assembler searches next C:\ASEM51\MCU and finally D:\MICROS\MCS51\INCL.2.) SET ASEM51INC=C:\ASEM51\MCU;%PATH%If ASEM51INC is defined as above in AUTOEXEC.BAT after the PATH statement, the assembler finally searches the directory C:\ASEM51\MCU and then all the directories, contained in the DOS program search path, from left to right!
The maximum length of <path> is limited to 255 characters. This cannot be exceeded with the SET command of the DOS command interpreter COMMAND.COM, but with third party command interpreters like 4DOS (max. 512 characters)!
Note that trailing blanks and tabs behind the names of environment variables
seem to be considered significant under