4 layers99.3 × 88.6 mm
2 layers132.6 × 60.5 mm
MinimalZ80
89Mods/misc-computers3Misc microcomputer projects
- Size
- 132.6 × 60.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 34
- Nets
- 67
- Pads
- 238
- Tracks, vias
- 657, 15
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 28 Sep 2023
- Updated
- 13 Sep 2026
Overview
MinimalZ80 is an open-source printed circuit board by 89Mods, from the 89Mods/misc-computers repository on GitHub, published under the MIT licence. It is a 2-layer board of 132.6 × 60.5 mm with 34 parts on 67 nets, routed with 657 tracks and 15 vias.
It is built around the 74HC240D, 74HC00D and 74HC02, with the 74LS573PC, CDP1824D and SM420561N among its other parts. Its parts include 16 resistors, 8 ICs, 4 switches, 3 connectors and 1 capacitor.
Main components
6
74HC240D
SO-20-300mil-40℃~+125℃ 1 11ns@4.5V,50pF 160uA 2V~6V 7.8mA 7.8mA 74HC 8 Tri-State Unidirectional SOIC-20-300mil Buffers, Drivers, Receivers, Transceivers ROHSNexperiaBuffer/Driver/Transceiver
74HC00D
SOP-14-40℃~+125℃ 1.5V、3.15V、4.2V 1.9V、3.7V、5.9V 100mV、400mV、400mV 2 2V~6V 4 40uA 5.2mA 5.2mA 500mV~1.8V 74HC Series 7ns@6V,50pF NAND Gate SOIC-14 Logic Gates ROHSNexperiaLogic Gates74HC02
-- Logic Gates ROHSonsemiLogic Gates
74LS573PC
DIP-200℃~+70℃ 10ns 3ns 4.75V~5.25V 74LS 8 D Latch Tri-State DIP-20 Latches ROHSTexas InstrumentsLatchesCDP1824D
SBDIP-18SRAMTexas Instruments
SM420561N
插件-20℃~+80℃ 0.56 1 12.6mm 19mm 25mcd 2V 50mW 7 Segment 8mm Common Cathode Red 插件 LED Segment Displays ROHSARKLEDLED Segment Displays
README
README.mdmisc-computers
Misc microcomputer projects I’ve built. More info @ https://tholin.dev/misc_comps
Contains hardware schematics and PCB design files (if applicable) for each computer, as well as example software.
I hope this repo will help people with building their own computers. You can either re-build one of the systems from here, or reference my code and schematics when designing your own.
Parts
34| Qty | Value | Footprint | References |
|---|---|---|---|
| 15 | 10K | Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal | R1, R2, R3, R4, R5, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16 |
| 4 | SW_Push_Dual | Button_Switch_THT:SW_PUSH_6mm_H7.3mm | SW1, SW2, SW3, SW4 |
| 2 | Conn_01x08_Female | Connector_PinHeader_2.54mm:PinHeader_1x08_P2.54mm_Vertical | J2, J3 |
| 1 | 100µF | Capacitor_THT:CP_Radial_D4.0mm_P2.00mm | C1 |
| 1 | 1K | Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal | R6 |
| 1 | 28C256 | Package_DIP:DIP-28_W15.24mm | U6 |
| 1 | 74HC00 | Package_DIP:DIP-14_W7.62mm | U1 |
| 1 | 74HC02 | Package_DIP:DIP-14_W7.62mm | U2 |
| 1 | 74HC240 | Package_DIP:DIP-20_W7.62mm | U8 |
| 1 | 74LS573 | Package_DIP:DIP-20_W7.62mm | U5 |
| 1 | CDP1824 | Package_DIP:DIP-18_W7.62mm | U7 |
| 1 | CXO_DIP8 | Oscillator:Oscillator_DIP-8 | X1 |
| 1 | LED | LED_THT:LED_D3.0mm_FlatTop | D1 |
| 1 | SM420561N | Display_7Segment:7SegmentLED_LTS6760_LTS6780 | U4 |
| 1 | Screw_Terminal_01x02 | TerminalBlock:TerminalBlock_bornier-2_P5.08mm | J1 |
| 1 | Z80CPU | Package_DIP:DIP-40_W15.24mm | U3 |
Questions
How big is the MinimalZ80 PCB?
It measures 132.6 × 60.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the MinimalZ80 use?
34 parts, built around the 74HC240D, 74HC00D, 74HC02 and 74LS573PC. 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 MinimalZ80 KiCad files?
From the 89Mods/misc-computers repository on GitHub, at the commit this page was made from: the board is z80_tester/MinimalZ80_HW/MinimalZ80.kicad_pcb and its schematic 8X305/HW/8X305.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the MinimalZ80 design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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