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Much of your computer is hidden in metal cases. Some of it is invisible to you. Behind the scenes are the fundamental parts of the computer. They consist of these elements: - hardware
All of the pieces that you can see, or touch,
or pick up, or move around compose the hardware of your computer.
- software
Recorded instructions that control the computer's operation. What you see of most programs is their names—you use their names to start them running—and their behavior, what they do when you use them. Many of these recorded instructions are so well hidden that you may never be aware of their existence. - files
Recorded information. A typical file might be a letter
that you write using the computer, or the accounting data that you
enter into the computer. Software is kept in files, too. There is a broad distinction between
files: some files hold only information of one kind or another; other
files (programs and their relatives) hold instructions that the
computer can follow.
Hardware | |
Hardware consists of several different parts, each having its own role. At the minimum, your MPE/iX hardware consists of these parts: a system processing unit (hidden inside the computer cabinet) peripherals (some are hidden inside the computer cabinet)
- system processing unit
The SPU. Often you will hear this called the central processing unit (CPU). This is the "brain" or "heart" of the computer. It is housed inside the computer box. Every instruction that you give to the computer passes through the electronic circuits of the SPU. Turning on a personal computer sets in motion a number of automatic functions that prepare the computer for work—usually in a matter of seconds or minutes. A multiuser system, such as your HP 3000 Series 9X8LX, requires time to start up, and it requires attention from someone who will perform many tasks to prepare the system for work. In general, there are very few occasions for turning off your computer. An emergency of some sort—overheating or some other malfunction—requires turning off the power to your computer. Some maintenance tasks also warrant turning off the computer: a change in the computer's configuration (adding or removing certain vital hardware), or physically moving the computer to another location.
Peripherals are all of the other hardware connected in some way to the system processing unit. They are sometimes referred to as peripheral devices, meaning that they exist outside the system processing unit itself. Peripherals, such as an internal disk drive, might be built into your system and thus hidden from view, or they might exist outside the computer box, as printers and terminals do. In one sense, a computer is a system processing unit plus everything else that might be connected to it. - terminal
Your screen and your keyboard, together. With the keyboard, you send instructions to the computer. The screen displays your instructions as you type them and displays the computer's response. There may be one or many connected to your computer. You may turn off your terminal at the end of the day, if you wish. Doing so will have no effect on the operation of the computer itself. - system console
A special terminal that serves as the main terminal for your computer. The person who manages your system uses the console to control the day-to-day functioning of the computer. There is only one of these connected to your computer. This terminal is vital to the operation of the computer and should not be turned off, except for special maintenance of the system. - disk drive
Information that you create or record, and all the programs that the computer uses, are stored on disk drives. There may be one or many attached to your computer. Your MPE/iX computer comes to you with at least one disk drive built into the computer cabinet. You can add one more internal drive and other, external disk drives, too. - tape drive
Information (files and perhaps programs) that you do not frequently use are stored on tape. The tapes might be magnetic, much like the tape used in a conventional tape recorder, or they might be digital data storage tapes (DDS). Your HP 3000 Series 9X8LX computer comes with a DDS tape drive installed in the computer cabinet, but you can add other, external tape drives, too. - UPS
An external uninterruptible power system that provides up to 15 minutes of battery backup power to the computer system. - printer
Printers come in all shapes and sizes. Some are designed for extremely high speeds. Some produce very high quality, finished documents. If there is only one attached to your computer, it may be referred to as the line printer. There might be more than one, however.
Software | |
Software are the programs that control all of the actions of the computer. Software determines whether the computer acts as a text processor, graphic artist, accountant, mail deliverer, or the many other roles that computers can play. The basic set of programs and files that come with your computer are called the fundamental operating system (FOS). You may, of course, add other programs from Hewlett-Packard or from other vendors who specialize in creating programs for the MPE line of computers. Regardless of their source, three types of software will be of most concern to you. - operating system
This is the "master" program that oversees and directs all of the programs that are used on your system. The operating system in your computer is called MPE/iX, MultiProgramming Executive (MPE) with Integrated Posix (iX). iX in the name means that your operating system has more memory and more computing power than its predecessors. - command interpreter
The command interpreter (CI) is a special program whose primary purpose is to read what you enter at your terminal, determine whether you have entered a command that the computer can accept, and then determine what to do about it. If you can log on, the CI is already at work and is waiting for you to issue a command. If the computer cannot carry out your command, the CI displays a message on your terminal. Such messages might consist of information about what is happening. They might be error messages that tell you that the computer cannot carry out your instructions. They might be warning messages to alert you that in some respect the action that you intended is not happening exactly as you expected it to occur. - other programs
The number and variety of programs that could be in your computer, waiting for you to use them, may be surprising, and more are being created every year.
The programs most commonly found on MPE/iX computers perform tasks such as
these: Parts and Pieces - electronic mail
sending and receiving messages - word processing
creating and printing documents of all sorts (sometimes called a text editor) - data processing
organizing and managing immense volumes of information, such
as inventory and orders management, mailing lists, and the like (usually recorded in a database) - forms creation
mimicking the kinds of paper forms that businesses use to collect, assemble, and organize information (frequently used in conjunction with a data processing program) - accounting
accounts payable and receivable, general ledger, payroll, billing,
and many others - process control
controlling other machinery in the manufacture of products, as well as monitoring and analyzing the performance of other (electronic) machinery
This list is far from exhaustive. HP Easytime/iX is a program, too—one that is designed expressly for managing your MPE/iX computer and using its many functions. You will find detailed information about using HP Easytime/iX in &using;. Programs are sometimes called applications. And, some programs on
the MPE/iX operating system are referred to as subystems. The
distinction between programs, applications, and subsystems is of
interest to the people who design them. In everyday use, the terms
are interchangeable and mean the same thing. Files | |
Files—recorded information or instructions—fall into two broad categories, data files and executable files. - data files
Data files include the letter or document that you might create, the database holding immense quantities of information, personnel records, financial records, and many others. What they have in common is that the information contained in these files is created and recorded by programs of one kind or another. - executable files
include all of the programs—recorded instructions—that direct the computer. Command files and job files are text (data) files. Unlike most data files, command files and job files contain instructions that the computer can interpret and carry out. Superficially, however, they behave like executable files. You will find more information about command files and job files in Chapters 8 and 9 of this book, and in the book Task Reference - HP 3000 Series 9X8LX (B3813-90009).
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