61c

61C is an alphanumeric designation that appears in multiple, unrelated domains. It does not correspond to a single, universally recognized entity, but one of its best-known uses arises in computer science education.

In academia, 61C is notably associated with UC Berkeley’s CS61C course, commonly written as CS61C and known as Machine Structures. This undergraduate course focuses on computer architecture and machine-level organization, covering topics such as data representation, assembly language, memory hierarchy, and basic performance considerations. It is part of the CS61x sequence of core computer science courses and is widely referenced within Berkeley’s EECS curriculum.

Beyond education, the combination of digits and the letter C is a common pattern in model numbers, part numbers, and catalog codes across various industries. In electronics manufacturing, for example, a suffix like C can indicate a particular revision, variant, or tolerance. In transportation and infrastructure planning, alphanumeric codes with a trailing letter are sometimes used to denote route variants or service loops. Because 61C can appear in many contexts, the exact referent typically requires additional context such as the issuing organization, geographic location, or product line.

See also CS61C for related information about the Berkeley course and its place in computer science education.