User's Manual Part 3

PERFORMING DOWNLOADS
Effect of Downloads on Existing Files and Data
76 OMNI 3600 REFERENCE MANUAL
When planning your download procedure, carefully consider the total amount of
memory space required to store certificates and signature files and the application
files. In some cases, a considerable number of 400-byte signature files reside in
terminal memory at any given time. Here are some general guidelines to follow:
• Know the size of available memory (RAM and flash) of the receiving terminal;
in back-to-back downloads, memory on both the sending and receiving
terminal.
• Know in advance how application files are redirected to RAM or flash and to
file groups other than the target group.
• Defragment flash memory before performing a download to optimize the
available space in the flash file system.
• Before you perform a download, use system mode menu selections to clear
the entire RAM and/or flash or the RAM or flash of a specific file group, as
necessary to ensure proper use of available memory in the target group.
Support for File
Compression
For information regarding file compression, refer to refer to the Verix Operating
System Programmer’s Manual (VeriFone part number 19733).
Effect of
Downloads on
Existing Files
and Data
When you download application files and data to an Omni 3600 terminal, an
important consideration is the effect of download procedure on existing
application files, files used in the file authentication process, and terminal
configuration settings stored in CONFIG.SYS files in the receiving terminal. Here
are some important points to remember:
• If a file already exists in the target file group, the existing file is replaced with
the new file of the same name. (Files in separate file groups can have identical
names.)
• Always download executable files (and any other files to logically protect
under VeriShield file authentication) together with the certificates and
signature files required to authenticate them.
• In full or partial application downloads, all CONFIG.SYS records on the
receiving terminal, both protected and non-protected (beginning with * or #),
are retained. New CONFIG.SYS variables included in the download package,
including the *GO variable, selectively replace existing variables with the
same key name in the CONFIG.SYS file of the target group.
• All current passwords are retained on the receiving terminal during an
application or operating system download (direct, by telephone, and back-to-
back). This includes the system mode password and file group passwords. If
required, you can replace existing file group passwords with new values as
part of the data transfer operation.
NOTE
Always modify the system mode password in a separate, securely-controlled
operation.