Skip to the content
2 layersMotherboard, the printed circuit board in 3D

Motherboard

ostertag/edu8

Educational 8 bit CPU

Full screenGitHub.kicad_pcb
Copper layers
2
Thickness
1.6 mm
Parts
68
Nets
263
Pads
690
Tracks, vias
0, 0
Routed
Not yet
KiCad
KiCad 9.0 (file 20241229)
Created
25 Feb 2026
Updated
2 Nov 2026

Overview

Motherboard is an open-source printed circuit board by ostertag, from the ostertag/edu8 repository on GitHub, published under the GPL-2.0 licence. It is a 2-layer board with 68 parts on 263 nets.

It is built around the 74HC21D, 74HC08D and 74HC04D. Its parts include 34 ICs, 18 resistors, 8 diodes and 8 connectors. It belongs with the computers and single-board computers boards of this library.

Main components

3

README

README.md

edu8

Educational 8 bit CPU

Parts

68
QtyValueFootprintReferences
810kResistor_SMD:R_0805_2012MetricR9, R10, R11, R12, R13, R14, R15, R16
81kResistor_SMD:R_0805_2012MetricR1, R2, R3, R4, R5, R6, R7, R8
874HC21Package_SO:SO-14_3.9x8.65mm_P1.27mmU14, U15, U16, U17, U27, U28, U29, U30
8LEDLED_SMD:LED_0805_2012MetricD1, D2, D3, D4, D5, D6, D7, D8
474HC08Package_SO:SO-14_3.9x8.65mm_P1.27mmU18, U19, U31, U32
25.1kResistor_SMD:R_0805_2012MetricR17, R18
2REG_INPUTSPackage_SO:SO-16_3.9x9.9mm_P1.27mmU1, U2
2REG_MISCPackage_SO:SO-16_3.9x9.9mm_P1.27mmU5, U6
2REG_OUTPUTSPackage_SO:SO-16_3.9x9.9mm_P1.27mmU3, U4
174HC04Package_SO:SO-14_3.9x8.65mm_P1.27mmU33
1Conn_ABConnector_PinSocket_2.54mm:PinSocket_2x08_P2.54mm_HorizontalJ1
1Conn_BPConnector_PinSocket_2.54mm:PinSocket_2x08_P2.54mm_HorizontalJ5
1Conn_CDConnector_PinSocket_2.54mm:PinSocket_2x08_P2.54mm_HorizontalJ2
1Conn_EFConnector_PinSocket_2.54mm:PinSocket_2x08_P2.54mm_HorizontalJ3
1Conn_SPConnector_PinSocket_2.54mm:PinSocket_2x09_P2.54mm_HorizontalJ4
1Conn_SWConnector_PinSocket_2.54mm:PinSocket_2x13_P2.54mm_HorizontalJ8
1DREG1_H_INPackage_SO:SO-16_3.9x9.9mm_P1.27mmU10
1DREG1_H_OUTPackage_SO:SO-16_3.9x9.9mm_P1.27mmU24
1DREG1_L_INPackage_SO:SO-16_3.9x9.9mm_P1.27mmU11
1DREG1_L_OUTPackage_SO:SO-16_3.9x9.9mm_P1.27mmU23
1DREG2_H_INPackage_SO:SO-16_3.9x9.9mm_P1.27mmU12
1DREG2_H_OUTPackage_SO:SO-16_3.9x9.9mm_P1.27mmU26
1DREG2_L_INPackage_SO:SO-16_3.9x9.9mm_P1.27mmU13
1DREG2_L_OUTPackage_SO:SO-16_3.9x9.9mm_P1.27mmU25
1REG1_INPackage_SO:SO-16_3.9x9.9mm_P1.27mmU7
1REG1_OUTPackage_SO:SO-16_3.9x9.9mm_P1.27mmU20
1REG2_INPackage_SO:SO-16_3.9x9.9mm_P1.27mmU8
1REG2_OUTPackage_SO:SO-16_3.9x9.9mm_P1.27mmU21
1REG3_INPackage_SO:SO-16_3.9x9.9mm_P1.27mmU9
1REG3_MANUAL_SWPackage_SO:SO-16_3.9x9.9mm_P1.27mmU34
1REG3_OUTPackage_SO:SO-16_3.9x9.9mm_P1.27mmU22
1Screw_Terminal_01x02TerminalBlock_4Ucon:TerminalBlock_4Ucon_1x02_P3.50mm_HorizontalJ7
1USB_C_Receptacle_PowerOnly_6PConnector_USB:USB_C_Receptacle_GCT_USB4125-xx-x-0190_6P_TopMnt_HorizontalJ6

More from ostertag/edu8

8
  • 2 layers100 × 70 mmClu shield, the printed circuit board in 3D

    Clu shield

    ostertag/edu8

    Educational 8 bit CPU

    59 partsGPL-2.0
  • 2 layers100 × 50 mmProgram counter, the printed circuit board in 3D

    Program counter

    ostertag/edu8

    Educational 8 bit CPU

    59 partsGPL-2.0
  • 2 layers90 × 45 mmRegister sp, the printed circuit board in 3D

    Register sp

    ostertag/edu8

    Educational 8 bit CPU

    59 partsGPL-2.0
  • 2 layers80 × 40 mmStep counter, the printed circuit board in 3D

    Step counter

    ostertag/edu8

    Educational 8 bit CPU

    59 partsGPL-2.0
  • 2 layers70 × 39 mmStatus word, the printed circuit board in 3D

    Status word

    ostertag/edu8

    Educational 8 bit CPU

    49 partsGPL-2.0
  • 2 layers75 × 28 mmRegister general, the printed circuit board in 3D

    Register general

    ostertag/edu8

    Educational 8 bit CPU

    42 partsGPL-2.0

Similar boards

  • 2 layers160 × 100 mmDCC V2, the printed circuit board in 3D

    DCC V2

    PaulVdBergh/DCC_Hardware

    The repository for DCC Hardware projects

    101 parts1
  • 2 layers58.9 × 66.5 mmNeopixel punk main, the printed circuit board in 3D

    Neopixel punk main

    astuder/neopixel-punk-console

    Blinking RGB LEDs with 555s and a handful of 74-series logic

    53 partsMIT
  • 2 layersCES, the printed circuit board in 3D

    CES

    erickpires/CES-PCB

    170 partsMIT
  • 4 layers100 × 100 mmEth, the printed circuit board in 3D

    Eth

    imihajlow/ccpu

    A 8-bit computer made of 74xx series logic gates and memory ICs.

    101 parts145
  • 2 layers106.7 × 83.8 mmVdu sv, the printed circuit board in 3D

    Vdu sv

    zuiko21/minimOS

    Scalable OS for 6502/65816

    40 parts23MIT
  • 4 layers99.8 × 99.8 mmDma mapped memory, the printed circuit board in 3D

    Dma mapped memory

    jimbro1000/dma-memory-module

    HD6309SBC DMA memory module

    36 parts
  • 2 layers175.3 × 80.6 mmSuS, the printed circuit board in 3D

    SuS

    stonedDiscord/Automatenplatinen

    Reverse engineerte Hardware aus deutschen Spielautomaten.

    88 parts5BSD-2-Clause
  • 2 layers180 × 67.5 mmNEW KANJI ROM, the printed circuit board in 3D

    NEW KANJI ROM

    bml3mk5/S1KanjiRomJIS2

    JIS Level 2 Kanji ROM Card for HITACHI MB-S1

    61 parts

Questions

What parts does the Motherboard use?

68 parts, built around the 74HC21D, 74HC08D and 74HC04D. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Motherboard KiCad files?

From the ostertag/edu8 repository on GitHub, at the commit this page was made from: the board is CAD/motherboard/motherboard.kicad_pcb and its schematic CAD/alu/alu.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Motherboard design in my own project?

Its repository publishes it under the GPL-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).