There was a recent thread about the Apple 1’s noisy -5 volt supply on Applefritter, so I asked Woz the following:

One thing a number of us have noticed while working with reproductions of the Apple 1, is the amount of noise that exists on the -5 volt supply. The stabiliy of the -5 volt rail appears to be affected by the edges of the -12 volt clock that is used to control the video shift registers. Usually it’s not a problem, but I’ve run across a few cases where it affected DRAM reliability. Adding additional decoupling to -5 near the shift registers and the -5 regulator seems to clean things up considerably.

I was wondering if any of you remember noticing that noise on the -5 volt supply and if that ever was an issue back “in the day”.

I recieved the following reply from Woz:

I am sure that what you describe is valid, although I personally wasn’t aware of it.

I did the prototype of the Apple I and debugged the PC board version but didn’t look into such aspects. I’m sure you are quite correct. We knew that this was a low volume product since we were demonstrating the Apple II before shipping the first Apple I. Hence, we did not have many to become aware of issues like this. Part of the problem was that my time was being spent on the Apple II completion.

The ‘productizing’ of the Apple I came under Steve Jobs. I always optimized my prototypes for short distance wiring, but the PC board introduced longer power traces. Please forgive me. I never looked closely at this aspect. I certainly over-minimized in bypassing decoupling capacitors throughout the chips and RAM. I did worse too that was probably copied over to the PC board, like not having pullup resistors on unused TTL inputs. Still, had we at Apple been aware of such an issue while selling maybe 150 Apple I’s, we could and would easily and quickly have rectified it. But we didn’t test fully a product that was a temporary place-holder before the big product. We did try to buy back every Apple I in exchange for Apple II’s.

We had more luck than anyone deserves with things working out just enough to suffice and do what we did.

I will tell you that I and others did observe the power lines and did not notice noise or spiking. And, as I said, it was never a problem that was called to our attention, or at least to my attention. We could have put out an errata sheet for owners to fix the problem themselves, since this was very much a maker product (local stores could modify things to use 16K RAM’s, for example, and they did.

I am totally interested in hearing such things even after all these decades. I awoke one night in Quito, Ecuador, this year and came up with a way to save a chip or two from the Apple II, and a trivial way to have the 2 grays of the Apple II be different (light gray and dark gray) but it’s 38 years too late. It did give me a good smile, since I know how hard it is to improve on that design.

best,
Woz

I was mentioned in a Robb Report article about the collectible value of vintage computers. It’s always an honor to be mentioned in the same article as Dag Spicer of the Computer History Museum.

http://robbreport.com/paid-issue/obsolete-power/page/0/4

There are a couple of original Apple 1’s that were put in briefcases.

One is owned by the “Main Personal Comptuer Museum” and is depicted on my registry page.

The one of interest for purposes of this blog entry is shown in an image shown on a webpage put up by the Silicium Museum organization. I don’t believe that the briefcase unit is the actual Apple 1 owned by the silicium organization. In fact, since I don’t have good documented images of their unit, I am just a bit skeptical about whether Silicium actually has an Apple 1. My standards for posting original Apple 1 information has risen since I added the Silicium unit, and if I recieved a similar report today, I might not have added their unit to the registry, at least until I recieved a good image.

However, it is interesting that I just got another historic look at this same briefcase Apple 1. It was shown on the program Computer Chronicles, which has it’s shows archived at the site archive.org. It can be seen at the beginning of a show entitled“Apple II Forever”.

I may have to add this unit to the registry, as a missing historic unit. There is a reference in the show to it being a museum piece. Since the show might have been taped in California, maybe it’s still sitting in some museum vault in the Bay Area.

By the way, there is no better way to understand the history of personal computers than to read vintage publications and view vintage videos. The archive of “Computer Chronicles” show is priceless. Check out Bill Gates participating in the Computer Bowl II.

I helped with the PCB layout for this cute little dongle. It has a clear screen switch, which isn’t normally available on an Apple II keyboard and does the rewiring necessary to connect a stock Apple II keyboard to an Apple 1, Mimeo or other clone. These are not needed for replica 1s, which has the keyboard pinout necessary to work with Apple II keyboards.

Here is one in action, hooked up between the keyboard and the Mimeo.

Keyboard Dongle

They are being sold by seller vintagemicros on eBay: ebay listing

One word of caution – be sure to connect pin 1 of cables to pin 1 on PCBs. If you reverse them, you will probably blow the 7404 on the keyboard’s encoder board.

One last thing, I connected pin 4 of the keyboard socket to the clear screen input on the Apple 1. Pin 4 is normally not connected on an Apple II keyboard, but if you make the keyboard encoder mod to use the repeat switch as clear screen input as described on Wendell Sander’s site, it will work without any further wiring changes.

This is the essence of a question someone asked on Applefritter.

Here are my thoughts on this topic.

It’s really not that complicated, people do this stuff cause it’s fun for them. This hobby is not for everyone. It’s about personality, if you don’t get it, you either haven’t been exposed to enough of the possibilities, or you have a different personality.

This question is really applicable to many different vintage systems with similar followings – the Apple 1 gets a lot of press because it’s the very first computer of a very successful company that, at the moment, happens to be near the top of it’s game.

There are three main activities in this hobby, with a little different motivation for each.

1) The collector – For some people, it is a lot of fun to own an item of significant historic value.
2) The operator – For some people, it is a lot of fun learning how to build or restore and operate a vintage computer.
3) The developer – Some people find it fun to expand the capabilities of vintage computers, providing capabilites to vintage machines that could not be dreamed of, back in the day.

There is a lot of crossover between the people participating in each of these activities.

For some of the rarer computers, you may decide it’s better to use a reproduction, rather than risk damage to an original machine or you may not be able to find or afford an original machine.

The reasoning behind installing date code original parts and making the reproduction as accurate as possible, is two fold.

In case you are trying to decide whether you might enjoy the hobby or not, consider this: how could you decide whether you might or might not like swimming, without going in the water?

Will be picking up the latest batch of Mimeos from the PCB fabricator this week (probably tomorrow). No changes from last batch.

At this point, I think I have some stock of all the PCBs that I have made since I started on this retro computer hobby.

Send an email to:mike@willegal.net if you have any questions or interest.