SOME USEFUL ADDITIONS TO THEOS Control and Sort

Control and Sort are two pieces of application software offered separately from THEOS by Phase One Systems that transform your

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computer system into a powerful data base manager. Control allows you to create data entry screens that are easy to use. You can use it to create card files, inventory files, or almost any type of data entry system. Once you have created the data entry screens, fill in the data and store it. You can then design any report format you prefer. The sort program allows sorting of the information created with the control program. Sort can also be used with other application software that lacks sorting capability or sorts too slowly.

RIM CObOpM

Rj M Cobol is a THEOS module available separately that is required to run programs written in the COBOL language. If you are looking at application software in the THEOS software directory, it will always indicate when Rj M Cobol is required to run the software, Although COBOL is a language preferred by many programmers, some experienced THEOS users (and programmers) have found that application software written in COBOL runs substantially slower than software written in THEOS BASIC.

File and Disk Management Utilities

The special programs called file and disk management utilities save considerable time and effort. In particular three programs from Quantum Information Systems are quite helpful. These programs are REORG, SQUEEZE, and QCOPY. They are described below.

The purpose of file and disk management utilities is to provide a simple solution to problems that may occur in managing THEOS files, such as maximizing disk space, and ensuring faster disk access .

.. The size of THEOS BASIC data files must be preallocated, and substantial degradation in the speed with which records in the file are accessed occurs when the files become seventy to eighty per cent full.

This creates a need to be able to resize these files as the user's require-ments change. Also, when records are deleted from these files, they are not truly removed but are simply delete coded. While records that have been delete coded may not be reused, they have the same effect on access time as if the record was not deleted. This creates the need to periodically "clear out the dead weight" so that the file contains only active records.

A similar problem arises with the disk directory. Time required to access the directory will degrade when it becomes seventy to eighty percent full. At this point there is a need to reorganize the directory and remove deleted entries in order to optimize file access time. A further problem may occur as files are added and deleted from the disk; the available space on the disk may become fragmented providing very little usable space in one location (remember, THEOS requires contin-uous space to write files). This creates the need to be able to compress the unused space on the disk into one contiguous area at the end of the disk where it is more useful.

REORG is a program that handles changing file sizes without losing data in the file. SQUEEZE is a program that handles the disk directory and disk space reorganization. Although it is possible to reorganize a disk by reinitializing it, SQUEEZE can perform the same operation and more, in less time, without reinitializing the disk.

QCOPY is a high speed copy program which reduces the time necessary to copy files. The QCOPY program is able to copy files two to four times faster than the COPYFILE program provided by THEOS, and eliminates the problem of copying files to multiple diskettes. It is not necessary to determine in advance how many files will fit on a disk. The program will copy files until no more will fit. The user is then prompted to insert another diskette. The procedure is repeated until all files h<;lve been copied. Before this particular program is purchased, it is recommended that the user work with the COPY-FILE command that is part of THEOS. Many users will find that COPY FILE does the job.

The Quantum utilities should be an integral part of every THEOS installation. REORG and SQUEEZE in particular can improve system speed and operating efficiency considerably.

Summary

Hardware manufacturers are constantly upgrading their compu-ters and trying to outperform their competition. In addition, they may provide certain enhancements to THEOS that will further improve their competitive edge. As a result, it is generally required that you buy

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THEOS from the same vendor as the hardware. Some hardware manufacturers supply THEOS with some additional software such as the packages described above. However, as long as the screens on your system resemble those we have described, you can be sure that the operating system you are using is THEOS.

THEOS includes features, many of which are found only on mainframe computers, that make it ideal for use in business. We have described some of these features and their benefits. You may find that certain features appeal to you more than others. As you begin to use THEOS in the next chapters, our goal is to help you feel comfortable using it and help you appreciate its advantages.

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