IO
About the IO PCB
IO is an open source PCB design by benanderman, published on GitHub under the MIT license. It is a 2-layer board measuring 99.6 × 59.9 mm, with 32 components from 11 distinct parts.
Other key parts include the C2682068. By type, the board carries 16 diodes, 4 ICs, 4 connectors, 4 capacitors and 4 resistors.
From the project
An 8-bit CPU, made with TTL chips on custom, modular PCBs. Includes board designs, and Arduino code to program its instruction set and programs.
This is an 8-bit computer project, inspired by Ben Eater's 8-bit breadboard computer. It's made out of modular PCBs that plug into each other, and contain mostly 74HC-series chips (original 74LS). It runs code from an EEPROM (so it's only programmable from a computer), and has separate memory. It's meant to display what's happening, when running on a 555-timer or manually stepping, but also be capable enough to implement some sort of game, when using an oscillator as a clock.
Main components on the IO
IO bill of materials (BOM)
32 components, 11 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | C2682068 74HC04 | DIP-14_W7.62mm | U1 |
| 2 | C2682068 74HC173 | DIP-16_W7.62mm | U2, U3 |
| 1 | C2682068 74HC245 | DIP-20_W7.62mm | U4 |
| 1 | CONN_01X12 Conn_01x16 | PinHeader_1x16_P2.54mm_Horizontal | J1 |
| 1 | Conn_01x16 | PinHeader_1x16_P2.54mm_Horizontal | J2 |
| 2 | Conn_01x14 | PinSocket_1x14_P2.54mm_Vertical | J3, J4 |
| 16 | C965793 LED | LED_D3.0mm_Clear | D1, D2, D3, D4, D5, D6, D7, D8 +8 |
| 4 | C307331 100nF | C_Disc_D4.3mm_W1.9mm_P5.00mm | C1, C2, C3, C4 |
| 1 | C25744 10k | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1 |
| 2 | 1k | R_Array_SIP9 | RN1, RN2 |
| 1 | 100k | R_Array_SIP9 | RN3 |
IO design files
The KiCad project lives in the benanderman/spork-8 repository on GitHub; these links point at the commit this page was built from.
- LayoutIO/IO.kicad_pcb
- SchematicIO/IO.kicad_sch
- BOMScreen/Screen-BOM.csv
IO: common questions
How big is the IO PCB?
The IO measures 99.6 × 59.9 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the IO?
32 components, from 11 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 IO design files?
From the benanderman/spork-8 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 IO design in my own project?
Yes, under the terms of its MIT license, which benanderman chose for the repository.
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Counter
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ALU
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Clock
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Bus
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Shift
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Register
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RAM
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Input
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