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Last Number Redial — lets you quickly review and redial any of the last 10 numbers that you called.

Scratchpad Memory — lets you temporarily store a number (even during a call), then easily dial it.

Security Features — to prevent unauthorized phone use, you can lock the phone (so it cannot be used at all) or set up to five different levels of service restrictions (so only local calls can be made, for example).

Multiple Key Answer — lets you set the phone so pressing one of several keys answers a call.

Ample Talk and Standby Time — the supplied battery pro- vides about 85 minutes of talk time or 24 hours of standby time, when fully charged.

Battery and Cellular Signal Strength Meters — easy-to- read graduated bar graphs let you quickly check the battery power remaining or the current cellular signal strength.

Automatic Answer — lets you set the phone to answer auto- matically after two rings (if you are using optional handsfree equipment, for example).

Two Phone Number Capability — lets you use this one phone with two different cellular services, with a different phone number from each.

Handsfree Feature — the phone is preprogrammed to work with most optional handsfree equipment.

We recommend you record your phone’s Electronic Serial Number (ESN) here. The number is on the back of the handset under the battery.

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Radio Shack CT-502 owner manual Fm Page 3 Wednesday, July 21, 1999 223 PM
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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.
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