{"product_id":"fpga-based-gigatron-ttl-kit","title":"FPGA-based Gigatron TTL kit","description":"\u003cp\u003eThis kit delivers a refined FPGA implementation of the Gigatron TTL microcomputer, originally built from discrete 7400-series TTL chips and ported to the Tang Nano 9K FPGA board\u003c\/p\u003e\n\u003cp\u003egigatron.io\u003c\/p\u003e\n\u003cp\u003ehackaday…\u003c\/p\u003e\n\u003cp\u003eThis kit delivers a refined FPGA implementation of the Gigatron TTL microcomputer, originally built from discrete 7400-series TTL chips and ported to the Tang Nano 9K FPGA board\u003c\/p\u003e\n\u003cp\u003egigatron.io\u003c\/p\u003e\n\u003cp\u003ehackaday.io\u003c\/p\u003e\n\u003cp\u003e. It includes a custom adapter board that handles video and audio D\/A conversion using discrete resistors and capacitors for an authentic retro experience\u003c\/p\u003e\n\u003cp\u003ehackaday.io\u003c\/p\u003e\n\u003cp\u003e. The VGA output now leverages an improved level-shifting scheme to eliminate the unstable signals observed with the original auto level converter\u003c\/p\u003e\n\u003cp\u003ehackaday.io\u003c\/p\u003e\n\u003cp\u003e. The XC9572XL CPLD originally used for voltage-level translation has been replaced with readily available components following its discontinuation. All resistor and capacitor networks have been reorganized into a cohesive SMD-only assembly for simplified soldering and lower cost. The result is a complete, low-cost, drop-in kit that preserves every Gigatron feature while providing a smoother build and stable performance for lightweight FPGA learning.\u003c\/p\u003e\n\u003cp\u003eWhat is it?\u003c\/p\u003e\n\u003cp\u003eA ready-to-solder FPGA-based replica of the Gigatron TTL microcomputer.\u003c\/p\u003e\n\u003cp\u003eIncludes FPGA bitstream for the Tang Nano 9K board, adapter PCB, all discrete components, and connectors.\u003c\/p\u003e\n\u003cp\u003eCompatible with standard VGA monitors (160×120 @ ~60 Hz) and NES-style game controllers\u003c\/p\u003e\n\u003cp\u003eWhy did you make it?\u003c\/p\u003e\n\u003cp\u003eTo overcome the original design’s VGA instability caused by its auto-conversion logic, avoid sourcing the discontinued XC9572XL CPLD, and simplify assembly by moving to an all-SMD RC network.\u003c\/p\u003e\n\u003cp\u003eWhat makes it special?\u003c\/p\u003e\n\u003cp\u003eStable VGA output with robust level shifting\u003c\/p\u003e\n\u003cp\u003eUses easily sourced, modern components in place of discontinued CPLDs\u003c\/p\u003e\n\u003cp\u003eClean, all-SMD passive network for quick assembly and low cost\u003c\/p\u003e\n\u003cp\u003eFully retains the vintage Gigatron instruction set, video, and audio capabilities\u003c\/p\u003e\n\u003cp\u003eVideos\u003c\/p\u003e\n\u003cp\u003eOriginal product page: \u003ca href=\"https:\/\/www.tindie.com\/products\/johnson\/fpga-based-gigatron-ttl-kit\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003ehttps:\/\/www.tindie.com\/products\/johnson\/fpga-based-gigatron-ttl-kit\/\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003eDocumentation\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/github.com\/kervinck\/gigatron-rom\/tree\/master\/Contrib\/docvolt\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eDocumentation\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/hackaday.io\/project\/196303-fpga-implementation-of-the-gigatron-ttl-computer?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eDesign Files\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"innoelement","offers":[{"title":"Default Title","offer_id":44575380439123,"sku":"TINDIE-FPGA-BASED-GIGATRON-TTL-KIT","price":22.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/0891\/1443\/files\/2025-07-02T04_46_46.735Z-_E5_BE_AE_E4_BF_A1_E5_9B_BE_E7_89_87_20250702120154.jpg?v=1778186366","url":"https:\/\/www.retromakerkits.com\/products\/fpga-based-gigatron-ttl-kit","provider":"RetroMakerKits by innoelement","version":"1.0","type":"link"}