03-03-88
This code is based on the work of Ray Duncan in his
book 'Advanced MS-DOS'- "The Microsoft guide for Assembly
Language and C programmers." published by Microsoft Press -
(C)1986 by Ray Duncan. The program SHELL.ASM is shown
on pages 199 - 205.

The code here is optimized for maximum speed of response and
the missing END statement has been added.

Mr. Duncan also presents a C version of this program
on pages 195 - 198 along with an excellent discussion
and explanation of the MS-DOS EXEC function.

This code and/or the C version is an excellent start for
building your own command interpreter. Items not recognized
by SHELL are passed to the MS-DOS COMMAND.COM for internal
or external processing.

As presented here a very minimal amount of memory is used
by the program. The C version would of course have a bigger
.EXE file and probably be slower.

'Advanced MS-DOS' covers almost all aspects of the DOS
interface for Assembly Language and C, it should be part of
your reference library if you are a programmer.


L. B. Neal
Sunnyvale, CA
March 3, 1988
PYSMATIC BBS 408-992-0372