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Archive for February, 2010

Monitor Test Working

February 19, 2010 Leave a comment

With my keyboard interface still incomplete I haven’t been able to do a full test of my Apple 1. However, I was able to enter the test program from the Apple 1 operations manual. The program ran just as expected.

Woz Monitor Test Program

Woz Monitor Test Program

At this point I am waiting for my replacement ATMEGA8515 for my IIe interface to arrive from Jameco. I figured out that I had accidentally connected D6 to pin 7 on the keyboard socket which is 12V+. This must have burned that pin causing it to no longer work. I am also finalizing the PCB layout to do a small run on these interface boards.

Apple IIe Keyboard Interface

February 17, 2010 Leave a comment

My effort to find the right keyboard for my Apple 1 was a long and relatively  fruitless process. Since the original Apple 1 did not supply a keyboard, a variety of keyboards were used. The requirement is that the keyboard needs to provide an ASCII interface that you can wire into the Apple 1 keyboard socket. A common choice for this was a Datanetics keyboard. As it turns out, datanetics and every other variety of ASCII keyboards have become very tough to find. As a result, people have done things such as create PS/2 interfaces to connect new keyboards. If you are lucky enough to find an original Apple II or Apple II plus keyboard, you can wire it directly into the Apple 1, but those keyboards are becoming rare and valuable. A slightly less rare and less valuable keyboard is from the Apple IIe, but these boards do not have an on board encoder.

Ultimately I decided that my best option was to try to use an Apple II keyboard for authenticity over a PS/2 keyboard. I could not find a reasonably priced II or II plus keyboard, so I decided to create an encoder for a IIe keyboard I already had. I leveraged information I found from some people who wanted to do the same thing. Design and assembly was pretty straight-forward, and went pretty quickly. In final testing I found that D6 on my ATMEGA8515 is broken and is wired to B7 on my Apple 1. Because B7 floats high, this has the effect of only being able to type in A-Z and no other keys work properly. I am ordering a replacement ATMEGA8515 and hope that with that my keyboard interface will finally be complete.

Top View

Top View

Bottom View

Bottom View

As soon as I get it working 100% I am going to do a small run on a few PCBs. I’ll post them when I do.

Apple 1 Video Noise Problem

February 17, 2010 Leave a comment

In Mike Willegal’s blog post Video Imperfection he described about a problem with the Apple 1 that caused dots to be seen on the screen when the brightness on a monitor was turned up to a very nigh level. This turns out to be true on his kits, the Obtronix clones and even the original Apple 1′s. Interesting, little-known problem. I snapped a couple pictures of my own Apple 1 to demonstrate.

Apple 1 With Normal Monitor Brightness

Apple 1 With Normal Monitor Brightness

Apple 1 With Increased Monitor Brightness

Apple 1 With Increased Monitor Brightness

Interesting Apple 1 History

February 8, 2010 1 comment

If you listen to any telling of the early days of Apple, it probably involves a couple of guys named Steve in one of their parents garage assembling computers by hand. While this makes a good story, its not exactly accurate. Intrigued by the fact that every Apple 1 I have ever seen was wave soldered (not hand soldered), I shot an email off to Woz to get some answers. His reply came 6 minutes later and was about as clear as could be:

We never designed or constructed any breadboards or computers in the garage. We picked up the wave soldered boards where they were made in Santa Clara and brought them to the garage for final assembly and testing.

I did construct either 2 or 3 Apple I’s by hand, with the chips tightly spaced on HP breadboards (just holes) and I used wirewrap wire cut to length for each wire I soldered on. It’s very compact that way and visible, compared to using wirewrap sockets. One of the Apple I’s I built this way was for my friend Randy Wigginton.

I still have my main Apple I prototype board.

I believe that I only constructed one Apple II that way.

So there you have it. The Apple 1 was never sold as a bare board and a bag of parts. The original 50 sold to the Byte Shop were not hand soldered by either Steve, or any of their friends for a dollar a board.

Categories: Apple 1 Tags: , , ,
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