A-ONE
I/O Interface Board
8-Bit
Input / Output Expansion for the A-ONE Apple-1 Replica
Expand your A-ONE system with real hardware interaction.
The A-ONE I/O Interface Board is a practical 8-bit input and output expansion card designed for the A-ONE Apple-1 replica platform. It allows users to directly read digital inputs and control external outputs from BASIC or machine code, making it perfect for retro-computing experiments, education, and hardware prototyping.
The board features a clear and intuitive layout with:
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8 red LED indicators for output monitoring
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8-position DIP switch input bank
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Selectable I/O addresses via jumpers
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Direct A-ONE bus connection
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Ready-to-use visual input/output testing platform
Ideal for learning how early microcomputers interacted with the outside world.
Key Features
How It Works
The A-ONE I/O board uses memory-mapped I/O, just like classic 1970s computer hardware.
The DIP switch provides an 8-bit binary input value, while the LED row shows the 8-bit output value written by the computer.
For example in BASIC:
A = 128
POKE -24576, A
This writes the value to the output port and lights the corresponding LEDs.
To read the switch settings:
B = PEEK(-24576)
PRINT B
This makes it a fantastic tool for learning how vintage computers communicated with real-world hardware.
Perfect For
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Retro computing enthusiasts
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Apple-1 / A-ONE collectors
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Educational demonstrations
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Binary and logic experiments
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BASIC programming projects
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Hardware interfacing
What’s Included
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1x A-ONE I/O Interface Board
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Fully assembled and tested
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Ready for direct use with your A-ONE system
Disclaimer
A-ONE is a modern replica system inspired by the 1976 Apple-1 computer. This product is not an original Apple product and is not affiliated with, endorsed by, or associated with Apple Inc. The name Apple-1 is used strictly as a historical reference for compatibility and educational purposes.