17-1111.fm Page 14 Wednesday, July 21, 1999 2:23 PM

BASIC OPERATION

TURNING THE PHONE ON/OFF

To turn on the phone, flip down the cover then press PWR . The phone performs a short self test and sounds a tone or vi- brates (see “Changing the Alert Type” on Page 29), then the signal strength meter appears (see “Signal Strength/Service Area”) and the keypad backlight turns on for about 16 sec- onds. The phone is ready to use when the green power/lock indicator begins to flash.

Notes: The keypad backlight turns on for about 16 seconds every time you press a key, then it turns off and the display goes blank to conserve battery power.

To turn off the phone, press PWR again. The display goes blank and the green on/lock indicator turns off.

SIGNAL STRENGTH/SERVICE AREA

Each time you turn on the phone, clear the display, or make a call, the signal strength meter appears on the display to indi- cate the strength of the cellular signal currently being re- ceived. The more bars that appear on the meter, the stronger the signal.

Notes:

If few or no bars appear (meaning the signal strength is weak) and you want to make or receive a call, move the phone to a different location so the signal strength increases.

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Radio Shack CT-502 owner manual Basic Operation, Turning the Phone ON/OFF, Signal STRENGTH/SERVICE Area

CT-502 specifications

The Radio Shack CT-502 is a remarkable device that stands out in the world of vintage technology, particularly known for its versatility and functionality as a portable computer. Launched during a time when personal computing was rapidly evolving, the CT-502 embodies the spirit of innovation that characterized the early days of computing technology.

At its core, the Radio Shack CT-502 comes equipped with a Zilog Z80 microprocessor, a staple of many early personal computers that provided solid performance for its time. This CPU offers an 8-bit architecture with a clock speed of 2.5 MHz, allowing users to execute tasks efficiently. The CT-502 features a memory capacity of 64 KB of RAM, which can be expanded, making it suitable for various applications, from basic text processing to simple programming tasks.

One of the standout features of the CT-502 is its dual built-in floppy disk drives, which enable users to easily load and save data. This was particularly advantageous during the era when storage solutions were evolving, as it allowed for quick access to programs and files. The 5.25-inch floppy disks used by the CT-502 became a standard for many personal computing applications, ensuring wide compatibility with software.

The device also features a compact, built-in keyboard that boasts a full set of function keys, essential for efficient data entry and navigation. Complementing the keyboard is a 40-character by 24-line monochrome display, which provides a clear view of text and applications, ideal for programming and document creation.

In terms of connectivity, the CT-502 includes a variety of ports such as serial and parallel interfaces, allowing users to connect external devices like printers and modems. This functionality enhanced the versatility of the system and integrated it into the growing network of computers.

Moreover, the Radio Shack CT-502 runs on the TRS-DOS operating system, designed specifically for the TRS line of computers. This operating system was user-friendly for its time, enabling users to manage files and perform various tasks without deep technical knowledge.

In summary, the Radio Shack CT-502 represents a significant milestone in early computing history, offering a combination of portability, ease of use, and expansion capabilities. With its reliable hardware, user-friendly interface, and diverse connectivity options, it remains a fondly remembered piece of technology that paved the way for modern personal computers.