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
Here’s a nostalgic look back at some of the AT commands we used:
- AT — Check if the modem is connected and responsive. Returns “OK” if connected.
- ATE0 — Disable command echo. The modem won’t echo commands back to the terminal.
- ATE1 — Enable command echo. The modem will echo commands back to the terminal.
- ATI — Display modem information, such as model and firmware version.
- ATZ — Reset the modem to its factory settings.
- AT&W — Save the current configuration to the modem’s non-volatile memory.
- AT&F — Restore factory settings.
- AT+MS=? — Display a list of supported modulation schemes and connection speeds.
- AT+MS= — Set the modulation scheme and connection speed.
- ATDT — Dial a phone number in tone mode. Example: ATDT5551234
- ATDP — Dial a phone number in pulse mode. Example: ATDP5551234
- ATH — Hang up the call.
- ATS0= — Set the number of rings before the modem answers an incoming call. Example: ATS0=1 (answer after one ring)
- AT+VCID= — Enable or disable Caller ID detection. Example: AT+VCID=1 (enable Caller ID)
- AT+VLS= — Set the modem’s speakerphone mode. Example: AT+VLS=1 (enable speakerphone)
- AT+VSP= — Set the modem’s speaker volume. Example: AT+VSP=2 (medium volume)
- AT+VRA= — Set the ringback timeout. Example: AT+VRA=20 (wait 20 seconds for ringback)
- AT+VNH= — Set the microphone gain. Example: AT+VNH=1 (low gain)
- AT+VDR= — Set the DTMF tone duration. Example: AT+VDR=100 (100 ms tone duration)
US Robotics Modem Commercial
Modem sound when connecting
Those were the days, weren’t they? If you’ve ever used these commands, you’re part of a unique era of internet history.