--- title: "How Commodore Made A Sync Splitter" url: https://daily.dev/posts/how-commodore-made-a-sync-splitter-mjjhaqvmu source_url: https://hackaday.com/2026/05/08/how-commodore-made-a-sync-splitter type: article source: "Hackaday" published: 2026-05-08T18:47:50.914Z updated: 2026-05-08T18:48:10.653Z tags: ["retrocomputing"] reading_time: 2 upvotes: 0 comments: 0 language: 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. # How Commodore Made A Sync Splitter **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 0 upvotes · 0 comments ## Summary A deep dive into the reverse engineering of a Commodore-designed sync splitter board found in a Commodore 64 housed in a PET case. The board takes composite video output from the VIC chip and splits out horizontal and vertical sync pulses for the monitor. The analysis explains why the board is necessary (the VIC chip combines signals internally), and how Commodore's engineers went beyond a simple passive filter approach by adding one-shots for clean pulse timing and logic gates for blanking. The digital TTL-level video path is also noted as a distinguishing feature from conventional analog sync splitters. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [A Commodore VIC 20 S-Video conversion](https://daily.dev/posts/a-commodore-vic-20-s-video-conversion-ghvtuvfo3) · Adafruit Blog · 0 upvotes · 0 comments - [Composite Video on the NES: Why's it so wobbly?](https://daily.dev/posts/composite-video-on-the-nes-why-s-it-so-wobbly--qteo1nuez) · Two Stop Bits · 0 upvotes · 0 comments - [This 8-Bit Commodore PET Was Hard To Fix](https://daily.dev/posts/this-8-bit-commodore-pet-was-hard-to-fix-jpfbwsfq7) · Hackaday · 0 upvotes · 0 comments - [Is It A Pet? No, It’s A Teacher’s Pet\!](https://daily.dev/posts/is-it-a-pet-no-it-s-a-teacher-s-pet--qu6viyxgu) · Hackaday · 0 upvotes · 0 comments --- Tags: [#retrocomputing](https://daily.dev/tags/retrocomputing) [View this post on daily.dev](https://daily.dev/posts/how-commodore-made-a-sync-splitter-mjjhaqvmu)