Browse Prior Art Database

Schedule Program Diskette File Structure

IP.com Disclosure Number: IPCOM000038429D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 4 page(s) / 78K

Publishing Venue

IBM

Related People

Pancoast, ST: AUTHOR [+2]

Abstract

A file structure is described that minimizes the fragmentation and wasted space caused by a large number of small files on a diskette. These files may vary in number and are of varying lengths. The Scheduler Program has three modes: Day, Week, and Month. The Day Mode allows the user to enter appointments on separate lines. The Week Mode displays the week at a glance with the first six open time ranges or first six nonblank appointments displayed. The Month Mode displays a month at a glance with a separate graphic for days that have text or a reminder set. The File Management used by the Scheduler Program eliminates the user's need to maintain calendar files. All file handling is done by the Scheduler and is transparent to the user.

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Schedule Program Diskette File Structure

A file structure is described that minimizes the fragmentation and wasted space caused by a large number of small files on a diskette. These files may vary in number and are of varying lengths.

The Scheduler Program has three modes: Day, Week, and Month. The Day Mode allows the user to enter appointments on separate lines. The Week Mode displays the week at a glance with the first six open time ranges or first six nonblank appointments displayed. The Month Mode displays a month at a glance with a separate graphic for days that have text or a reminder set. The File Management used by the Scheduler Program eliminates the user's need to maintain calendar files. All file handling is done by the Scheduler and is transparent to the user. The File Management Read function performs the read of the day subfile from the diskette month file by reading blocks of 512 characters pointed to by the month file's FAT (File Allocation Table entries. The File Management Write function performs the write of the day text to the diskette month file by writing the day text to diskette using the first open FAT entry found in the month FAT table for each 512-character block of the day text. A file structure used by a Scheduler Program to group the days of the month and reminders for those days under a single DOS file is described. The DOS file is partitioned for up to 31 days. This file structure was required to minimize file fragmentation and wasted space caused by a large number of small files on a diskette. The maximum number of files varies with the number of days in a month and the lengths of these files may vary each time the day schedule is saved. Using a partitioned file structure (i.e., month file) to hold a large number of small files
(i.e., day schedules) on a personal computer diskette is unique to this Scheduler Program. A day schedule is contained within a month DOS file that is partitioned for up to 31 days. The month DOS file is named according to the formula mmyyyy, where mm is the two-character month and the yyyy is the four-character year. For example, 031956 = March 1956 By this formula, the scheduler can determine the month file name without intervention by the user. A directory entry, as shown in Table 1, consists of a one- character FAT pointer, a two-character length and a one-character reminder field. The FAT pointer points to the head of the FAT chain that makes up the day file. The length indicates the number of characters in the day file. The reminder field specifies whether the reminder is set for a day. Directory

Month = Binary month number (01-12 = January - December)

Year = Binary year (0-9999)

FATptr = Pointer to first entry in FAT chain (0-256)

Length = Length of file (0-4096)

Remind = Flag to indicate the reminder is on or off (0 or 1)

Table 1 The FAT pointer in the directory is also an index into the FAT Table. The FAT Table shown in Table 2

1

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consists of 256 one-chara...