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Large update to README.md
Add twitter thread through nitter proxy, links to OSH Park projects, lots of info, a few images uploaded (one more is needed at R61 end result)
Clarissa Walker authored on 2022/04/16 04:27:03
• GitHub committed on 2022/04/16 04:27:03
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# ka2195d-model2gen |
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+## Introduction |
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Project that aims to fix the Model 2 Sega Genesis's composite video clock that uses the console's crystal oscillator instead of using an external one. |
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-This repo contains the schematic, PCBs, and Gerber files for the Composite Video clock fix for Model 2 Sega Genesis consoles: revision VA0, VA1, and VA1.8 boards. Removal of R61 on the console's board is **_required_**. |
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+This repo contains the schematic, PCBs, and Gerber files for the Composite Video clock fix for Model 2 Sega Genesis consoles: revision VA0, VA1, and VA1.8 boards that contain the infamous Samsung KA2195D NTSC video encoder. The Gerber files can be used for other PCB fabs. |
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+Notes: |
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+* These are KiCad 6 files, so KiCad 5 and earlier will not work with these. |
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+* This does not fix the RGB jailbars, as it is a somewhat different (yet related) issue. |
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+* This particular PCB uses Imperial 1206 size SMD components. |
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+* Removal of the original 10K resistor on R61 on the console's board is **_required_**. |
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+* R61_L is +2.5V as VREF, connecting to SBCR. |
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+* R61_R is GND, connecting to C24, then KA2195 pin 6. |
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+-- |
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+## Details |
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+This [twitter thread (through nitter.net)](https://nitter.net/AmiSapphire/status/1496249012688756744) is the original instruction-like thread (with video examples as well). In short: |
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+* you remove R61 from the board |
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+* mount the board to the console's CPU |
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+* have one wire connect to R61's left pad from the R61_L pad |
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+* have one wire connect to R61's right pad from the R61_R pad |
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+* have one wire connect as ground to wherever ground can be, e.g. C4's right pad, C1's left pad |
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+-- |
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+## Images |
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+R61 Pad Indicators: |
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+R61 End Result: |
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+-- |
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+## OSH Park order links |
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+Original (test): https://oshpark.com/shared_projects/IpuYYXQL |
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+SMD Hand Solder: https://oshpark.com/shared_projects/toKAOWpJ |
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+Through Hole: https://oshpark.com/shared_projects/uN65Pqal |