| Abbreviation | Definition |
|---|---|
| ASTC | Audio Sector Timecode |
| ASTC | Audio Sectored Timecode |
| ASTM | American Society for Testing and Materials |
| ASTTL | Advanced Schottky Transistor-Transistor Logic |
| ASUR | Active Set Update Rate |
| ASW | Augmented Spherical Wave |
| ASYNC | ASYNChronous |
| ATA | Advanced Technology Attachment |
| ATC | Ampere Time Counter |
| ATC | Automatic Temperature Compensator |
| ATDF | Advanced Technology Development Facility |
| ATE | Automatic Test Equipment |
| ATEC | Advanced Technologies in Electrical and Communications |
| ATEE | Advanced Topics in Electrical Engineering |
| ATEES | Advance Technologies For Electronic Enrollment System |
| ATF | Automation Test Facility |
| ATG | Analogue Transfer Gate |
| ATG | Automatic Test Generation |
| ATLAS | Abbreviated Test Language for All Systems |
| ATLAS | Asteroid Terrestrial-impact Last Alert System |