The Hush-a-Phone decision applied only to mechanical collections, but the Carterfone decision of 1968 led to the FCC introducing a rule setting stringent AT&T-designed tests for electronically coupling a device to the phone lines. AT&T's tests were complex, making electronically coupled modems expensive,^{[citation needed]} so acoustically coupled modems remained common into the early 1980s.
However, the rapidly falling prices of electronics in the late 1970s led to an increasing number of direct-connect models around 1980. In spite of being directly connected, these modems were generally operated like their earlier acoustic versions - dialling and other phone-control operations were completed by hand, using an attached handset. A small number of modems added the ability to automatically answer incoming calls, or automatically place an outgoing call to a single number, but even these limited features were relatively rare or limited to special models in a lineup. When more flexible solutions were needed, 3rd party "diallers" were used to automate calling, normally using a separate serial port.