Nostalgic Journey: Hayes-Compatible Modems and AT Commands

This post is dedicated to those who remember the days of using Hayes-compatible modems to connect to the internet. Back then, we relied on serial communication applications like HyperTerminal or Minicom to configure our modems. The AT+MS command was used to set the modulation scheme and connection speed, while the ATDT or ATDP command dialed our ISPs.

My favorite modem was US Robotics 56K

U.S. Robotics 56K Message Modem

AT Commands:

Here’s a nostalgic look back at some of the AT commands we used:

1. AT — Check if the modem is connected and responsive. Returns “OK” if connected.
2. ATE0 — Disable command echo. The modem won’t echo commands back to the terminal.
3. ATE1 — Enable command echo. The modem will echo commands back to the terminal.
4. ATI — Display modem information, such as model and firmware version.
5. ATZ — Reset the modem to its factory settings.
6. AT&W — Save the current configuration to the modem’s non-volatile memory.
7. AT&F — Restore factory settings.
8. AT+MS=? — Display a list of supported modulation schemes and connection speeds.
9. AT+MS= — Set the modulation scheme and connection speed.