AT&T Archives: The Step-By-Step Switch
Overview
A 1951 Bell System training film showing how telephone calls are routed through a step-by-step (Strowger) switching office.
On Hacker News
HN uses it as a favorite old explainer for mechanical telephone switching.
Topics
Sources
Video by AT&T Tech Channel, played through YouTube.
Data and selection notes
HN summaries and labels may contain AI errors. HN dates refer to discussions, not video publication.
HN Library: HackerTube export (2026-10-31) and open-index/hacker-news. Upstream summaries and classifications may contain AI errors.
Views, duration and playback status refresh separately from the published catalog. When an update fails, existing data remains visible.
Selection checks
- SaaS & AI candidates: Topic keywords do not match
- Editor-approved picks: Editorial review is required
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