Browse Prior Art Database

Hiding the Hard File Subdirectory Structure in OS/2

IP.com Disclosure Number: IPCOM000102106D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 43K

Publishing Venue

IBM

Related People

Miller, MM: AUTHOR

Abstract

A program is disclosed that shields the knowledge of the subdirectory structure on the PS/2* hard file from microcode applications in the Processor Console.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 80% of the total text.

Hiding the Hard File Subdirectory Structure in OS/2

       A program is disclosed that shields the knowledge of the
subdirectory structure on the PS/2* hard file from microcode
applications in the Processor Console.

      To allow for the flexibility of moving data from one
subdirectory to another with minimal impact and to enhance OS/2*
system performance, a programming convention was developed which
required Processor Console microcode to interface with a Disk File
Controller (DFC) before actually accessing the data on the PS/2 hard
file.  The job of DFC was to add the path (logical drive and
subdirectory) to the requested file name and then call the proper
OS/2 function.

      The path information is kept in a separate ASCII file, which is
read into memory on the very first DFC request. The path information
is then kept in memory and used for all subsequent DFC requests for
the remainder of time the Processor Console is powered on.  The file
containing the path information consists of a "file key" and
corresponding OS/2 path data.  The "file key" consists of 13
characters made up of an 8-byte file name and a 3-byte extension.
The thirteenth byte is a '.' (period), which separates the file name
and extension (See the figure).  Both the file name and extension can
contain "wild card" characters (a question mark).  The table is
searched sequentially and the "file key" and the passed file name are
compared one byte at a time.  Before the compare, the pas...