IBM, sonic delay lines, and the history of the 80×24 display
12 hours ago
- #Display Standards
- #Terminal History
- #IBM
- The popularity of 80×24 and 80×25 displays stems from IBM's dominance in the terminal market, starting with the IBM 3270 in 1971.
- Punch cards influenced the 80-column standard, while IBM's terminals standardized the 24-line display, later adjusted to 25 lines in the IBM PC.
- Early terminals had diverse screen sizes, but market forces and IBM's influence led to the convergence on 80×24 and 80×25 displays.
- Technical theories about terminal sizes (e.g., TV scan rates, memory constraints) are debunked by the variety of early terminal dimensions.
- The IBM 2260 (1965) and 3270 (1971) terminals were pivotal in shaping display standards, with the 3270's 80×24 display becoming a de facto standard.
- The IBM PC's adoption of an 80×25 display in 1981 further cemented these dimensions, diverging from the 24-line standard of other contemporary systems.
- Market reports from the 1970s and 1980s highlight IBM's role in standardizing terminal sizes, overshadowing technological limitations.