--- title: Energizing A Vacuum Tube Flip-Flop Module Of The IBM 604 description: Ken Shirriff examines the TR-3 trigger module from the 1948 IBM 604 Electronic Calculator, a pluggable unit built around a 2033 dual triode vacuum tube... canonical: https://daily.dev/posts/energizing-a-vacuum-tube-flip-flop-module-of-the-ibm-604-ktvr5ua7q twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Energizing A Vacuum Tube Flip-Flop Module Of The IBM 604 | daily.dev og:description: Ken Shirriff examines the TR-3 trigger module from the 1948 IBM 604 Electronic Calculator, a pluggable unit built around a 2033 dual triode vacuum tube... og:url: https://daily.dev/posts/energizing-a-vacuum-tube-flip-flop-module-of-the-ibm-604-ktvr5ua7q og:image: https://api.daily.dev/og/posts/KTVr5UA7q.png og:image:alt: Energizing A Vacuum Tube Flip-Flop Module Of The IBM 604 og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Energizing A Vacuum Tube Flip-Flop Module Of The IBM 604 **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 0 upvotes · 0 comments ## Summary Ken Shirriff examines the TR-3 trigger module from the 1948 IBM 604 Electronic Calculator, a pluggable unit built around a 2033 dual triode vacuum tube implementing a flip-flop circuit. The module generates timing signals and pulses central to the 604's operation. After wiring it up, Ken successfully triggered it, though it requires a stable input signal. The post also notes how IBM later replaced this analog flip-flop design with diode logic in the 1954 IBM 650, a step toward the more reliable Boolean logic that would define early transistorized computers. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Energizing a vacuum-tube flip-flop module from a 1948 IBM system](https://daily.dev/posts/energizing-a-vacuum-tube-flip-flop-module-from-a-1948-ibm-system-srore98wj) · Hacker News · 0 upvotes · 0 comments - [Powering Up A Pluggable Module From The 1948 IBM 604 Electronic Calculator](https://daily.dev/posts/powering-up-a-pluggable-module-from-the-1948-ibm-604-electronic-calculator-tjfbmopcs) · Hackaday · 0 upvotes · 0 comments - [A Vacuum Tube Computer For The Home](https://daily.dev/posts/a-vacuum-tube-computer-for-the-home-7xdfchmgw) · Hackaday · 0 upvotes · 0 comments --- Tags: [#retrocomputing](https://daily.dev/tags/retrocomputing) [View this post on daily.dev](https://daily.dev/posts/energizing-a-vacuum-tube-flip-flop-module-of-the-ibm-604-ktvr5ua7q) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Energizing A Vacuum Tube Flip-Flop Module Of The IBM 604","url":"https://daily.dev/posts/energizing-a-vacuum-tube-flip-flop-module-of-the-ibm-604-ktvr5ua7q","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/energizing-a-vacuum-tube-flip-flop-module-of-the-ibm-604-ktvr5ua7q"},"datePublished":"2026-08-03T23:10:03.671Z","dateModified":"2026-08-03T23:10:24.890Z","description":"Ken Shirriff examines the TR-3 trigger module from the 1948 IBM 604 Electronic Calculator, a pluggable unit built around a 2033 dual triode vacuum tube...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/9a66f517a3d94993394547fca8c57360?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/9a66f517a3d94993394547fca8c57360?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hackaday","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hackaday","logo":"https://media.daily.dev/image/upload/s--JhDfhy70--/f_auto,q_auto/v1767541814/logos/hackaday","url":"https://daily.dev/sources/hackaday"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/energizing-a-vacuum-tube-flip-flop-module-of-the-ibm-604-ktvr5ua7q","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"retrocomputing","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hackaday","item":"https://daily.dev/sources/hackaday"},{"@type":"ListItem","position":3,"name":"Energizing A Vacuum Tube Flip-Flop Module Of The IBM 604"}]} ```