Alu-32b
About the Alu-32b PCB
Alu-32b is an open source PCB design by tmarhguy, published on GitHub under the SHL-2.1 license. It is a 4-layer board measuring 240 × 240 mm, with 115 components from 6 distinct parts.
Other key parts include the 74ACT151, 74HC86, 74HC00 and 74ACT283. By type, the board carries 57 ICs, 57 capacitors and 1 connector.
From the project
A functional 32-bit computer built from scratch in a dorm; implemented on FPGA, Kicad, browser simulation
Archive lot for early ALU board work. The living Dual-LUT PCB is 07alu**. The prior 8-bit discrete-transistor story (270×270 mm, ~3,488 devices) is documented at alu.tmarhguy.com.
Project map: Boards · 07_alu · Root README
Monolithic 8-bit ALU — complete combinational processor on a single PCB (historical reference below).
Components: - 8× 1-bit full adders (336T) - 8× XOR gates for B input (96T) - Carry chain routing
Main components on the Alu-32b
Alu-32b bill of materials (BOM)
115 components, 6 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 33 | 74ACT151 | SOIC-16_3.9x9.9mm_P1.27mm | U1, U2, U3, U4, U5, U6, U7, U8 +25 |
| 8 | 74HC86 | SOIC-14_3.9x8.7mm_P1.27mm | U17, U27, U37, U47, U57, U67, U77, U87 |
| 8 | 74HC00 | SOIC-14_3.9x8.7mm_P1.27mm | U19, U29, U39, U49, U59, U69, U79, U89 |
| 8 | 74ACT283 | SOIC-16_3.9x9.9mm_P1.27mm | U20, U30, U40, U50, U60, U70, U80, U90 |
| 1 | Conn_02x16_Counter_Clockwise | PinSocket_2x16_P2.54mm_Vertical | J5 |
| 57 | 100nF | C_0603_1608Metric | C16, C18, C20, C22, C24, C25, C26, C28 +49 |
Alu-32b design files
The KiCad project lives in the tmarhguy/tomato repository on GitHub; these links point at the commit this page was built from.
Alu-32b: common questions
How big is the Alu-32b PCB?
The Alu-32b measures 240 × 240 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the Alu-32b?
115 components, from 6 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the Alu-32b design files?
From the tmarhguy/tomato repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.
Can I use the Alu-32b design in my own project?
It is published under SHL-2.1, which limits how it may be reused; read the license before building on it.
