Description:

Lot of 5 vintage logic ICs marked SN74ALS42N / 74ALS42. The 74ALS42 is a high-speed BCD-to-decimal (1-of-10) decoder / demultiplexer in a 20-pin DIP package. This Advanced Low-power Schottky (ALS) device offers significantly faster switching and lower power than the standard 74LS series. Ideal for retro computer repair, arcade hardware, and industrial control projects. Surplus/NOS parts; untested.

Modern uses:

- Retro-computer / arcade PCB repair (74ALS42/7442-family logic)

- BCD digit decoding for counters, selectors, and state machines

- Educational TTL/ALS logic projects (demux / line select applications)

Technical Note:

- Package: DIP-20 (PDIP-20)

- Interface Type: Parallel

- Operating Temp: 0°C to 70°C (Commercial Grade)

- Features Totem-pole (Push-Pull) outputs (sinks and sources current).

- Outputs are active-LOW.

- Check logic family (ALS vs LS/HC/HCT) before substituting.

- ESD sensitive; store in ESD-safe packaging.