2 layers99.1 × 99.7 mm
2 layers191.5 × 97.6 mm
Open Apple 1 SBC
davischris/OpenAC14This work is largely based on the work of Tor-Eirik Bakke Lunde (https://github.com/tebl/RC6502-Apple-1-Replica).
- Size
- 191.5 × 97.6 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 72
- Nets
- 159
- Pads
- 471
- Tracks, vias
- 2,325, 64
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 6 (file 20211014)
- Created
- 5 Jul 2023
- Updated
- 4 Apr 2026
Overview
Open Apple 1 SBC is an open-source printed circuit board by davischris, from the davischris/OpenAC1 repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 191.5 × 97.6 mm with 72 parts on 159 nets, routed with 2,325 tracks and 64 vias.
It is built around the PIC32MX250F128B-I/SS, 74HCT00D and 74HCT04D, with the 74HCT138D, HM62256BLP-7 and L7805 among its other parts. Its parts include 18 capacitors, 18 resistors, 12 connectors, 11 ICs and 2 diodes. It belongs with the computers and single-board computers boards and the PIC boards of this library.
Main components
8
PIC32MX250F128B-I/SS
SSOP-28-208mil-40℃~+85℃ 10bit 128KB 19 2.3V~3.6V 32 Bit 32KB 40MHz Built-in FLASH MIPS32 M4K SSOP-28-208mil Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
74HCT00D
SO-14-40℃~+125℃ 100mV、400mV 12ns@4.5V,50pF 2 2V 3.7V、4.4V 4 4.5V~5.5V 40uA 4mA 4mA 74HCT Series 800mV NAND Gate Overvoltage-tolerant input TTL Compatible CMOS SO-14 Logic Gates ROHSNexperiaLogic Gates74HCT04D
SO-14-40℃~+125℃ 1 19ns@4.5V,50pF 2V 2uA 3.7V 4.5V~5.5V 400mV 4mA 4mA 6 74HCT 800mV SO-14 Inverters ROHSNexperiaInverters
74HCT138D
SO-16-40℃~+125℃ 160uA 20ns@4.5V,50pF 3/8 4.5V~5.5V 4mA 4mA 74HCT Decoder Single Supply SOIC-16 Signal Switches, Multiplexers, Decoders ROHSNexperiaSignal Switches / Encoders & Decoders / Multiplexers
HM62256BLP-7
DIP28DIP28 New Arrivals ROHSHITUncategorised
L7805
TO-220ST0℃~+125℃@(Tj) 1 1.2A 20V 2V@(1A) 42uV 500uA 5V 73dB@(120Hz) Fixed Positive Short Circuit Protection TO-220ST Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSOSENVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
MCP23S17-E/SO
SOIC-28-300mil-40℃~+125℃ 1.8V~5.5V 10MHz 16 1uA 600mV 8 8mA Interrupt Output Reset function、Cascading and address extension SPI SOIC-28-300mil I/O Expanders ROHSMicrochip TechnologyI/O Expanders
NE555P
DIP-80℃~+70℃ 100kHz 10mA 4.5V~16V DIP-8 555 Timers / Counters ROHSTexas InstrumentsTimers / Counters
README
README.mdOpenAC1
This work is largely based on the work of Tor-Eirik Bakke Lunde (https://github.com/tebl/RC6502-Apple-1-Replica). I really liked his project and I had just read "Apple 1 Replica Creation: Back to the Garage" by Tom Owad, so I was very interested in making a "workalike" Apple 1.
I wanted to extend this project to include USB keyboard and VGA monitor support, as well as the ability to read programs from an SD card.
This project also includes code from other open source projects including Geoff Graham's VT100 Teminal Emulator (https://geoffg.net/terminal.html) including David Hansel's modification to use a USB keyboard.
Parts
72| Qty | Value | Footprint | References |
|---|---|---|---|
| 11 | 100nF | Capacitor_THT:C_Disc_D3.8mm_W2.6mm_P2.50mm | C1, C4, C5, C6, C7, C8, C9, C10, C11, C12, C18 |
| 5 | 3.3k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1, R6, R7, R8, R10 |
| 4 | Hole | rc6502:Mounting | J1, J2, J3, J4 |
| 3 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R9, R12, R18 |
| 2 | 10uF | Capacitor_THT:CP_Radial_D4.0mm_P2.00mm | C3, C17 |
| 2 | 150 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R11, R14 |
| 2 | 27pF | Capacitor_THT:C_Disc_D3.8mm_W2.6mm_P2.50mm | C13, C14 |
| 2 | 4.7k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R13, R17 |
| 1 | 103 | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C2 |
| 1 | 104 | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C15 |
| 1 | 1M | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2 |
| 1 | 1MHz | Oscillator:Oscillator_DIP-14 | X1 |
| 1 | 1k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R4 |
| 1 | 220 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R15 |
| 1 | 28C64/28C256 | Package_DIP:DIP-28_W15.24mm | U2 |
| 1 | 330 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R5 |
| 1 | 334 | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C16 |
| 1 | 470 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R16 |
| 1 | 47k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3 |
| 1 | 74HCT00 | Package_DIP:DIP-14_W7.62mm | U3 |
| 1 | 74HCT04 | Package_DIP:DIP-14_W7.62mm | U5 |
| 1 | 74HCT138 | Package_DIP:DIP-16_W7.62mm | U1 |
| 1 | 8MHz | Crystal:Crystal_HC49-U_Vertical | Y1 |
| 1 | A13 Select | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | A1 |
| 1 | A14 Select | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | A2 |
| 1 | Activity | LED_THT:LED_D5.0mm | D2 |
| 1 | Arduino Nano | Module:Arduino_Nano | J6 |
| 1 | BARREL_JACK | Connector_BarrelJack:BarrelJack_Horizontal | CON1 |
| 1 | CLEAR | Button_Switch_THT:SW_PUSH_6mm | SW2 |
| 1 | COMP VIDEO | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | P2 |
| 1 | CONN_02X22 | Connector_PinHeader_2.54mm:PinHeader_2x22_P2.54mm_Vertical | P1 |
| 1 | DB15_Female_HighDensity | Connector_Dsub:DSUB-15-HD_Female_Horizontal_P2.29x1.98mm_EdgePinOffset3.03mm_Housed_MountingHolesOffset4.94mm | J7 |
| 1 | EXT CLEAR | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP3 |
| 1 | EXT RESET | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP1 |
| 1 | HM62256BLP-7 | Package_DIP:DIP-28_W15.24mm | U4 |
| 1 | L7805 | Package_TO_SOT_THT:TO-220-3_Vertical | U10 |
| 1 | MCP23S17 | Package_DIP:DIP-28_W7.62mm | U8 |
| 1 | NE555P | Package_DIP:DIP-8_W7.62mm | U6 |
| 1 | PIC32MX250F128B | Package_DIP:DIP-28_W7.62mm | U11 |
| 1 | Power | LED_THT:LED_D5.0mm | D1 |
| 1 | Power | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | A4 |
| 1 | Power Switch | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP2 |
| 1 | Prog Enable | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | A3 |
| 1 | RESET | Button_Switch_THT:SW_PUSH_6mm | SW1 |
| 1 | SD Card Module | Connector_PinHeader_2.54mm:PinHeader_1x06_P2.54mm_Vertical | P3 |
| 1 | USB_A | Connectors:USB_A | P4 |
| 1 | VP GND | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J5 |
| 1 | WD65C02/R6502 | Package_DIP:DIP-40_W15.24mm | U9 |
| 1 | WD65C21/MC6821 | Package_DIP:DIP-40_W15.24mm | U7 |
Questions
How big is the Open Apple 1 SBC PCB?
It measures 191.5 × 97.6 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Open Apple 1 SBC use?
72 parts, built around the PIC32MX250F128B-I/SS, 74HCT00D, 74HCT04D and 74HCT138D. 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 Open Apple 1 SBC KiCad files?
From the davischris/OpenAC1 repository on GitHub, at the commit this page was made from: the board is hardware/OpenAC-1/Open Apple 1 SBC.kicad_pcb and its schematic hardware/OpenAC-1/Open Apple 1 SBC.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Open Apple 1 SBC design in my own project?
Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
Similar boards
- 2 layers368.3 × 215.9 mm
- 2 layers
LM80C R6
leomil72/LM80C
A Z80-based homebrew computer withTMS9918, AY-3-8910, Z80 CTC, Z80 PIO, and Z80 SIO
153 parts123GPL-3.0 - 2 layers235 × 158.8 mm
Gigatron
flypie/Gigatron
This is a version of the files from https://gigatron.io/ altered to work on a vanilla KiCAD 5.1.6. Changes are minimal in the schematic and PCB, layout has only been changed where dimensions or orientations changed as a…
151 parts2 - 4 layers120.2 × 104.1 mm
- 2 layers150 × 90 mm
- 2 layers297.2 × 180.3 mm
- 2 layers184 × 80 mm
Adcboard
nuclearfutureslab/ibxII-hardware
Hardware for IBX ][ - nuclear warhead verification with an Apple II
126 parts5GPL-3.0