I have a A-one extended. Beautiful system, well designed and build. A-ONE hardware design: Franz Achatz , Video controller Software: San Bergmans, Keyboard controller Software: Ben Zijlstra
SB-Projects, San Bergmans’ description of the working of the Apple 1 and all about the A-ONE
The A-ONE is a compact and high quality Apple 1 replica made and designed in the Netherlands by Achatz Electronics. Similar, but not identical to the Apple 1 Replica 1. Advantages are the small board size and low IC count,, 50 Hz and 60 Hz rock solid video, and the real Apple 1 slot.
Specifications:
- CPU: MOS TECHNOLOGY 6502
- System-Clock: 1 MHz
- RAM Memory: 32KB SRAM
- ROM Memory: 32KB (64KB EPROM, selectable are two banks)
- Video: 40 Chars/line at 24 Video-lines 50Hz and 60Hz
- Video Out: Composite positive Video, 75 Ohms
- Keyboard: PS/1 Keyboard interface
- RS232: 9-pin SubD Female, 2400 Bd
- Expansion: 2×22 Edge Connector
- Powersupply: recommended is single universal AC-DC Adapter
- Voltage: DC 9-12VDC
- Supply Current: 250 mA
- PCB Size: 160 x 100mm
A-ONE Extended
The A-ONE Extended is a standard A-ONE with additional a large breadboard and three Apple 1 slots. Together with the breadboard prototype board this make it quite an impressive system to develop hardware for 6502 systems!

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A-ONE manual 1.10 |
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A-ONE manual 1.10 |
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Elektuur announcement |
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A-ONE flyer |
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A-ONE terminal description by San Bergmans |
Jumpers: JP1: Video 50/60Hz JP2: MemoryMap (see Manual) JP3: H-A14 = 65C02 CPU A14-L = 6502 CPU
Downloads
- Firmware: sources, hex files, ROM
- Software: Basic programs, Microchess, Krusader, A1 assembler by San Bergmans and more
A-ONE extensions
Since the Apple 1 slot is standard, it must be possible to use the Apple 1 and Replica 1 extensions, such as the CFFA1 and the multi-I/O board on the A-ONE. It will need a A-One slot to Apple 1 slot onnection, perhaps via one of the prototype boards.
Working with the A-ONE extended becomes even more a pleasure with the prototype boards sold by Achatz Electronics.
A-ONE information
The design of the A-ONE is well documented and open: see the excellent website of San Bergmans
See also:
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