Remote control by telephone

In this article we describe a system which enables you to control and check the status of electrical appliances by means of commands sent over the public switched telephone network (PSTN). That's right, no boxes crammed with hardware, and no problems with BT type approval: all you need are a PC and a Hayes-compatible modem at both sides of the link. Mind you, this equipment need not be state-of-the art: with some restrictions, even old 286-ATs and 2400-baud modems can be dusted off to do the job.