Accessories and Other Hardware

particular printer has two settings: draft mode and letter-quality (LQ) mode. PITCH BUTTON Use the pitch button to select the number of characters to print per inch. This particular printer has three settings: 10, 12, and 17 characters per inch. Indicator and Warning Lights.— In looking at figure 1-24, you will notice indicator lights located above the control buttons on the control panel. They provide status information and show the functions or features currently in effect. POWER INDICATOR The power light lets you know that power is being supplied to the printer. ONLINE INDICATOR The online indicator tells you that the printer is in online status and is ready to receive output from the microprocessor. While it is in this status, normally, all other panel buttons are inoperative. ERROR INDICATOR The error indicator light warns you that there is a problem of some sort that makes the printer inoperable. This could be caused by a cover left open, the printer out of paper, an electrical malfunction, a paper jam, or possibly the font cartridge is not in place or is improperly seated. FONT, PRINT MODE, AND PITCH INDICATOR LIGHTS The lights located above each button and next to each feature tell you the current operating modes of the printer. The lights are lit next to selected features. Accessories and Other Hardware In addition to monitors, disk drives, keyboards, and printers, you may find a number of other attachments to microcomputer systems. These might include a mouse device, cassette tape drive, optical scanner, CD-ROM drive, switch box, modem, and so on. MOUSE DEVICE.— You may have a mouse device attached to your micro. It allows you to freehand sketch or to select items from menus on the display screen. As you move the mouse, the cursor moves to a corresponding location on the display screen. For example, if you are selecting an item from the menu, you move the cursor to the item and press a button on the mouse to select the item. TAPE DRIVE.— You can use cartridge or cassette tapes to provide backup to the hard drive. The tape drive may be internal or external to the system unit. A tape drive makes a good, reliable backup system for the micro, since it holds 60MB or more of data. If a tape drive is not available, you can backup to floppy disks. OPTICAL SCANNER.— An optical scanner can be used to scan (read) graphic art or text directly into the microcomputer. This saves redrawing or retyping. CD-ROM DRIVE.— You may have a CD-ROM (compact disk-read only memory) drive to read data stored on compact disks. CD-ROM technology is the same as that used for audio disks, except it includes routines for detection and correction of data errors. The CD-ROM drive can be internal or external to the system unit. Compact disks can hold a vast amount of information, 550MB or more. They are used when the same information is needed by many, and the information is fairly constant. For example, libraries can put all the information they need about documents and publications on a CD-ROM. On a CD-ROM, the 1-23