{"product_id":"minimax-4-bit-cpu-td4-architecture-cpu-sbc","title":"Minimax 4-bit CPU - TD4 Architecture CPU\/SBC","description":"\u003ch3\u003eWhat is it?\u003c\/h3\u003e\u003cp\u003eThe \u003cstrong\u003eMinimax 4-bit CPU\u003c\/strong\u003e is an improved version of the classic \u003cstrong\u003eTD4-CPU\u003c\/strong\u003e architecture — a Turing-complete 4-bit processor built from fewer than 20 logic gate chips. Using a \u003cstrong\u003e16×4 DIP switch ROM\u003c\/strong\u003e, you program it manually with no programmer required: just flip the switches and run. It’s an ideal hands-on tool for beginners learning assembly language and computer architecture from first principles.\u003c\/p\u003e\u003ch3\u003eWhat makes it special?\u003c\/h3\u003e\u003cp\u003eThe Minimax improves on the original TD4 in several meaningful ways:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eExpanded register file\u003c\/strong\u003e — adds a 16×4-bit register file addressed by a pointer register, compared to the original TD4’s two general-purpose registers\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVariable-length instruction decoding\u003c\/strong\u003e — single-length (4-bit) instructions execute directly; double-length instructions (8-bit with immediate data) are automatically detected, buffered, and executed — achieving \u003cstrong\u003e100% ROM utilization\u003c\/strong\u003e under any instruction combination\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo program status registers\u003c\/strong\u003e — CF (carry flag) and ZF (zero flag) enable conditional branching\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4-bit input and output ports\u003c\/strong\u003e — output drives a 7-segment display showing 8421BCD code with latch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstruction set:\u003c\/strong\u003e NOP, ADD, SUB, CMP, IN A, OUT A, MOV A\/reg, MVI A\/P, JMP, JMZ, JMC, JNC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdjustable clock speed:\u003c\/strong\u003e 0–100 Hz — slow enough to watch each instruction execute step by step\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSingle 5V power supply\u003c\/strong\u003e via Type-C connector\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOptions Available\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully Assembled\u003c\/strong\u003e — ready to program and run out of the box\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePCB Only\u003c\/strong\u003e — bare PCB for those who want to source and solder their own components\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eExternal Links\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e\u003ca href=\"https:\/\/github.com\/denjhang\/MiniMax-4-bit-CPU\"\u003eGitHub: MiniMax-4-bit-CPU\u003c\/a\u003e\u003c\/li\u003e\u003c\/ul\u003e","brand":"Denjhang's Retro Hardware","offers":[{"title":"Default Title","offer_id":46123573706949,"sku":null,"price":158.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0777\/8507\/1813\/files\/2023-09-26T15_21_50.275Z-minimax_1.jpg?v=1777005904","url":"https:\/\/denjhang.myshopify.com\/products\/minimax-4-bit-cpu-td4-architecture-cpu-sbc","provider":"Denjhang's Retro Hardware","version":"1.0","type":"link"}