Vintage Netronics ELF II CDP 1802 Computer Board, 256 Bytes, It
Item History & Price
Reference Number: Avaluer:19189603 | UPC: Does not apply |
This is the famous ELF II computer board produced by Netronics R&D Ltd. in the late 1970s. I bought it assembled, rather than as a kit, at that time. I worked with it a little bit in those days and then put it into storage (not intentionally, but that is the way it worked out).
If you examine the photos you can see that I attempted to implement the cassette tape storage interface for the computer. I don't know if that works or not; I have not tried it now and I... certainly don't remember.
However, I did just now enter the 13 byte Q-LED test program described in the article "Build a Personal Microcomputer for $100", written by Martin Meyer, that was published in the 1978 Electronic Experimenter's Handbook. I was able to enter this program and run it successfully twice. I stopped at that point. The HEX switches need cleaning -- the bytes were not always entered correctly, but the success rate was over 95% I estimate.
I am also including a set of related articles that I gathered back in the day. If you are interested in this computer, you probably have most of these already, but perhaps there will be something useful to you here. The articles are:
Expanding the ELF II, by Martin Meyer, Popular Electronics, March 1978.
How to Upgrade a Basic ELF Microcomputer, by Edward M. McCormick, Popular Electronics, February 1978.
Utilities & Music on the COSMAC ELF, by Edward M. McCormick, Dr. Dobbs Journal, Number 19.
A Tic-Tac-Toe Game for your ELF Computer, by Edward M. McCormick, Popular Electronics, November 1978.
A 16-bit Math Package for ELF Computers, by R. S. Fitzgerald, Popular Electronics, August 1982.
The Amazing 1802: D/A and A/D Applications, by Dr. Robert J. Cotter, Kilobaud, Number 20, August 1978.
For shipping, I plan to separate the circuit board from its particle board supports, as this will make it easier to support the board robustly without damaging it. It might also be a good idea to desolder (or cut away completely) the power wires and the cables for the cassette interface before packaging for shipment. I will take direction from the new owner on this matter, it such direction is offered. All parts shown in the pictures will be included in the shipment, of course.
If you examine the photos you can see that I attempted to implement the cassette tape storage interface for the computer. I don't know if that works or not; I have not tried it now and I... certainly don't remember.
However, I did just now enter the 13 byte Q-LED test program described in the article "Build a Personal Microcomputer for $100", written by Martin Meyer, that was published in the 1978 Electronic Experimenter's Handbook. I was able to enter this program and run it successfully twice. I stopped at that point. The HEX switches need cleaning -- the bytes were not always entered correctly, but the success rate was over 95% I estimate.
I am also including a set of related articles that I gathered back in the day. If you are interested in this computer, you probably have most of these already, but perhaps there will be something useful to you here. The articles are:
Expanding the ELF II, by Martin Meyer, Popular Electronics, March 1978.
How to Upgrade a Basic ELF Microcomputer, by Edward M. McCormick, Popular Electronics, February 1978.
Utilities & Music on the COSMAC ELF, by Edward M. McCormick, Dr. Dobbs Journal, Number 19.
A Tic-Tac-Toe Game for your ELF Computer, by Edward M. McCormick, Popular Electronics, November 1978.
A 16-bit Math Package for ELF Computers, by R. S. Fitzgerald, Popular Electronics, August 1982.
The Amazing 1802: D/A and A/D Applications, by Dr. Robert J. Cotter, Kilobaud, Number 20, August 1978.
For shipping, I plan to separate the circuit board from its particle board supports, as this will make it easier to support the board robustly without damaging it. It might also be a good idea to desolder (or cut away completely) the power wires and the cables for the cassette interface before packaging for shipment. I will take direction from the new owner on this matter, it such direction is offered. All parts shown in the pictures will be included in the shipment, of course.