TTL logic family, plastic case and part of the 74 series of devices which were released in 1966 and became the industry de-facto standard. These are the Low-Power Schottky variants which require much less power but the downside was they have slower gate speeds.
Look inside any electronic equipment from the 1980's ~ 1990's and it is very likely you will find some 74LS devices.
NATIONAL SEMICONDUCTOR
Type: 74LS157
Part #: DM74LS157N
Function: Quad 2 input multiplexer
16 pin DIL plastic
NEW Old Stock
Always stored & these will be supplied in a suitable ESD tube
NEW Old Stock
