From scratch

16 boards

KiCad boards from 2 GitHub repositories tagged “from-scratch”, the most starred first; open any of them in PCBKit.

2 layers110 × 117 mm
Add sub
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
200 parts48MIT
4 layers70 × 50 mm
Stage0 5
essen48183/MinAI
A single-file C++ transformer built to be read — every mechanism of a modern LLM in ~780 lines, with a textbook companion.
72 partsMIT
2 layers41 × 35.5 mm
Flags
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
26 parts48MIT
2 layers42.5 × 32.5 mm
Gate and 2in
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
9 parts48MIT
2 layers
Gate and 4in
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
10 parts48MIT
2 layers10.5 × 31 mm
Gate inv 1bit
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
4 parts48MIT
2 layers18.5 × 32.8 mm
Gate nand 2in
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
7 parts48MIT
2 layers23.3 × 32.5 mm
Gate nor 2in
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
7 parts48MIT
2 layers57.5 × 36 mm
Gate or 2in
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
9 parts48MIT
2 layers77.5 × 43 mm
Gate xnor 2in
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
19 parts48MIT
2 layers72 × 42.5 mm
Gate xor 2in
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
19 parts48MIT
2 layers101 × 68 mm
Led panel 1
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
131 parts48MIT
2 layers78.5 × 68.5 mm
Led panel 2
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
129 parts48MIT
2 layers43.5 × 50.5 mm
Led panel 3
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
35 parts48MIT
2 layers59 × 63 mm
Main control
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
42 parts48MIT
2 layers98.5 × 95.5 mm
Main logic
tmarhguy/alu
8-bit combinational ALU built from scratch with 3,488 CMOS transistors (KiCad + SPICE + Logisim + 1.24M tests
122 parts48MIT