README.DOC

December 13, 1985

This diskette contains two versions of ISAM. 

One version, ISAM.EXE, is version 2.30, and should be
used if you have a stand-alone, or non-IBM PC environment.
If it is used in a network environment, locking affects the
entire file instead of a single record.  It will allow ISAM
files OPENed for INPUT to be read simultaneously by
different processes, however.  There are also some speed im-
provements over ISAM.EXE version 2.26.  This version of ISAM
will support MS-NET compatible networks as well as the 
IBM PC-NET.

The second version of ISAM is designed to be used in an IBM
PC-NET network environment and requires PC-DOS v 3.1 or
greater.  It consists of three files: NISAM.EXE, ISAM.SRV,
and ISAM.RDR.

NISAM.EXE is the front end ISAM command processor, version 
 3.0.  The commands it accepts are:

NISAM START SRV | RDR {/S:NNNNN}  --start network ISAM
                                 (/S: specifies buffer size)
NISAM STOP                        --stop ISAM & free memory
NISAM SHARE                       --show share list, as with
                                    server
NISAM SHARE shortname=d:\path     --share a directory with
                                    the specified shortname
NISAM SHARE d:\path               --share the specified
                                    directory
NISAM SHARE shortname|d:\path /D  --stop sharing the short-
                                    name or directory
NISAM FILE                        --show the currently OPEN
                                    ISAM files
NISAM CLOSE name                  --close the specified open
                                    file

ISAM.SRV is the server version of ISAM which can service 
ISAM requests.  It is activated by the NISAM START SRV 
command.  This command should be given on a network
server machine when requests for ISAM files located on that
machine will be made either locally or across the network.

ISAM.RDR is the redirector version of ISAM, and is activated
by the NISAM START RDR command.  This command should be 
given on network machines that run programs that access ISAM
files located only on other, server machines.

Thus, ISAM files must be located on a server, and the ISAM
on that machine must be activated with the NISAM START SRV
command.

Note:  It is possible, in the same network, to have some 
machines running ISAM.EXE and others running NISAM.EXE.
We do not recommend it, however.  It is NOT possible to
have the same machine running both ISAM.EXE and NISAM.EXE
at the same time.

Like the network server, network directory paths must be
shared using the NISAM SHARE command.  The command syntax
has been modeled after the NET SHARE command.  You MUST
NISAM SHARE the same directories that you NET SHARE, using
the SAME syntax used in the NET SHARE command.
For example, on a server named ZEKE you would type:

	NET SHARE PAYABLE=C:\LEDGER\PAYABLE
	NISAM SHARE PAYABLE=C:\LEDGER\PAYABLE

Then, the user on another machine who wants to use an ISAM
file in the C:\LEDGER\PAYABLE directory on the server named
ZEKE would type:

	NET USE E: \\ZEKE\PAYABLE

and then run the application which OPENs the ISAM file on 
drive E:.

The application can be passed the name of the machine\short-
name to do an explicit OPEN using the "VALUE OF FILE-ID"
clause.  For example:

	VALUE OF FILE-ID "\\ZEKE\PAYABLE\MASTER.DAT".