Page 6 - Issue 4 - Disk Sort

Disk Sort

Peter Franey, West Midlands

Issue 4

Jul/Aug 83

This program is a little too long to be used as a tutorial, however it is a useful way to illustrate the ways in which the disk directory can be used and tailored for your own needs. The program can be used in its own right but by studying the listing you may be able to learn how to use your disk drive to greater advantage. The main menu will also give you a brief insight into modifying display lists.

PROGRAM OPTIONS

1. DISK DIRECTORY - This option allows you to sort the directory in alphabetical order, either by main file name or extension. The advantages of sorting by EXTension name are that you can group together programs of similar function provided of course you use an extension representative of the program type. Both the option of main file name and extension are given in the sort routines. By altering the lines indicated in the REM statements or even deleting them completely, you may control the types of file read from the directory. Bear in mind that if this is done not all of the files will be displayed or included in the file count.

2. RUN PROGRAM - This option allows the user to select and run a program from the disk, by single stepping through the directory. If the stepping continues to the end of the directory, the program will return to the main menu. The instructions for this option are displayed on the screen.

The line by line description of the program is as follows:

10

dimension variables and goto menu

30 - 100

open and get directory - append to work string

110 - 160

sort menu

190 - 250

sort main file names

590 - 660

sort by extension

700 - 740

deposit file data in utility string in ranked order

745 - 790

print results

1100 -1370

modify display list

1500 - 1600

display directory for option 2

1610

exclude 'list' files

1620 - 1660

compile correct file name format for RUN

Without the REM statements the program will take up 44 sectors on a disk.

The main disadvantage of the program is that the alphabetical sort will take several seconds. The more files that are on your disk, the longer it will take. The main reason for the longish time for this sort is that after sorting, the directory is deposited, in the correct order, in a utility string which is then used in a rolling display. This part of the program can be improved.

AtariLister - requires Java

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