The Telocator Alphanumeric Protocol (TAP) is a telecommunications protocol that is used to send short alphanumeric messages to alphanumeric pagers or paging devices. It was widely used in the past to deliver short text messages to pager devices. Here’s a brief overview of the TAP protocol:

1. Character Set: TAP uses a limited character set, typically based on the 7-bit ASCII character encoding. This character set includes alphanumeric characters, punctuation marks, and a few control characters.

2. Message Length: Messages sent using TAP are typically limited to a certain number of characters, often around 240 characters. Longer messages may need to be broken into multiple parts.

3. Protocol Structure: A TAP message typically consists of a sequence of frames. Each frame includes specific information such as the recipient’s pager number, the sender’s information, message text, and control information. These frames are sent as binary data.

4. Pager Addresses: In TAP, pager addresses are typically numeric and correspond to specific pager devices. These addresses are used to specify the recipient of the message.

5. Acknowledge and Error Handling: TAP allows for acknowledgment and error handling. The sender can receive an acknowledgment from the pager device if the message is successfully received. This feature is important for ensuring message delivery.

6. Transmission: TAP messages are transmitted using a variety of methods, including dial-up modem connections, dedicated data networks, or other forms of communication.

TAP was widely used in the 1990s and early 2000s for sending short messages to pagers, but it has largely been replaced by more modern and versatile messaging technologies, such as SMS (Short Message Service) and mobile messaging apps. These newer technologies offer richer features, support for multimedia content, and are compatible with smartphones, making them more suitable for today’s communication needs.

If you have any specific questions or need more detailed information about the TAP protocol or its history, please feel free to ask.