This weekend I completed two small projects I needed in order to bring up the Apple 1.

First was what I am calling a power entry module (PEM). This contains the transformers, on/off switch and fuse. As this point I’m not planning on including the switch and fuse and associated wiring with the kits, since choice of components depends alot on the type of enclosure you will be housing your Apple 1 in. For initial bringup, I’ve put together the PEM, so that I don’t have exposed 110 volt wiring near the computer while I’m working on it. Eventually I plan on building a nice acrylic case for everything, but that will come later.

Note that in building this unit, I was reviewing the instructions in the Apple 1 operations manual. The diagram had the switch on one side of the AC line and the fuse on the other. Keep in mind that I’m far from an expert in this area. However, I’m thinking that this isn’t a very safe design. Common household wiring normally has 3 wires, commonly called the hot, common and ground. The hot sources the voltage and common is the return. Normally the common will be close to a ground potential. If the switch is connected to the hot wire and the fuse the common, then if the fuse blows, and the switch is left on, then there will be potential voltage in the system, just with nowhere to flow. If the reverse is done, then there will be potential voltage in the system anytime the system is plugged in, unless the fuse blows. I’m thinking that the proper way to wire this system is to put both the fuse and the switch on the “hot” wire” and then if either the fuse is blown or the switch is off, then there will not be potential voltage in the system. Please let me know if you think that I am off base here.

Second thing I put together is an Apple II to Apple 1 keyboard converter. This was done using a couple of spare wirewrap sockets and some perf-board, all out of the scrap box. The total cost was nil. John Calende has a nice blog describing what needs to be done.

http://apple1computer.blogspot.com/

Here is my quick and dirty wirewrapped version, mounted in a small wooden box I made from scrap wood. I’m thinking of adding a clear screen button to this converter.