You will need to do the following steps to be able to take advantange of
changing the Sybase Packetsize:

1) go to our web site:
http://www.sas.com/techsup/download/maint/access/sybase/HPU8/6.12

2) download the following files:
    sassyb.o.packet
    sassyb10.o.packet 
    sassyb101.o.packet
    sassyb46.o.packet
    sassyb461.o.packet
    vzrlchr.o.packet
    vzstlen.o.packet
    MCN_sassyb.o.packet
    PCN_sassyb.o.packet
    zdbisyb.ins.packet

3) cd !SASROOT/saspgm/dbi/obj

4) rename the following modules that are in this directory to have .orig or
.old on the end of their names so that you have a backup copy of these
files. 

Please make sure that you do not already have .orig files in this directory
(if you do then this would totally overwrite your original files).  You 
should put some other suffix on the modules.

            mv sassyb.o sassyb.o.orig
            mv sassyb10.o sassyb10.o.orig
            mv sassyb101.o sassyb101.o.orig
            mv sassyb46.o sassyb46.o.orig
            mv sassyb461.o sassyb461.o.orig
            mv MCN_sassyb.o MCN_sassyb.o.orig
            mv PCN_sassyb.o PCN_sassyb.o.orig
            mv !SASROOT/install/zdbisyb.ins
            !SASROOT/install/zdbisyb.ins.orig
             


5) change directory to the directory where the newly downloaded files are
located. Then rename the files that you downloaded to be as follows:
          mv sassyb.o.packet sassyb.o
          mv sassyb10.o.packet sassyb10.o
          mv sassyb101.o.packet sassyb101.o
          mv sassyb46.o.packet sassyb46.o
          mv sassyb461.o.packet sassyb461.o
          mv MCN_sassyb.o.packet MCN_sassyb.o
          mv PCN_sassyb.o.packet PCN_sassyb.o
          mv vzrlchr.o.packet vzrlchr.o
          mv vzstlen.o.packet vzstlen.o
          mv zdbisyb.ins.packet zdbisyb.ins

6) copy these renamed files that you downloaded to the
   appropriate directory.
          cp sassyb.o !SASROOT/saspgm/dbi/obj
          cp sassyb10.o !SASROOT/saspgm/dbi/obj
          cp sassyb101.o !SASROOT/saspgm/dbi/obj
          cp sassyb46.o !SASROOT/saspgm/dbi/obj
          cp sassyb461.o !SASROOT/saspgm/dbi/obj
          cp MCN_sassyb.o !SASROOT/saspgm/dbi/obj
          cp PCN_sassyb.o !SASROOT/saspgm/dbi/obj
          cp vzrlchr.o !SASROOT/saspgm/dbi/obj
          cp vzstlen.o !SASROOT/saspgm/dbi/obj
          cp zdbisyb.ins !SASROOT/install


where !SASROOT is where sas is installed.


ONCE THE FILES ARE IN PLACE, THE FOLLOWING MUST BE DONE:
-------------------------------------------------------

You will need to redo the link by invoking sasmanager and following 
appendix b of the installation instructions for sas/access to sybase.
You will not want to choose to use the prelinked module.  

The Sybase SQL Server must be set up to accept a maximum value.  The
database administrator must use sp_configure in isql to set this up.
An example is shown below:

use master
go
sp_configure "network packet size", 4096
go

This will cause a Sybase user to specify any packet size up to and
including 4096.

In order to be able to change the packetsize for SAS to recognize, 
you will need to set the SYBPACKET environment variable to 
a value. This value can be up to and including 32K.  The default
packet size without this being set is 512.  There are several
examples below:
                  export SYBPACKET=1024
                  export SYBPACKET=2048
                  export SYBPACKET=4096