Download the 74F242 datasheet PDF.
This datasheet also includes the 74F243 variant, as both parts are published together in a single manufacturer document.
QUAD BUS TRANCEIVERS WITH 3-STATE OUTPUTS
The MC54/74F242 and MC54/74F243 are Quad Bus Transmitters/Receivers designed for 4-line asynchronous 2-way data communication between data buses.