Archive for the ‘Apple II’ Category

Apple II rev 0 reproduction gerber and CAD files available for download

Wednesday, November 8th, 2017

I have made available Apple II rev 0 reproduction gerber and CAD files freely available for download. I actually put these files online a little while back, but didn’t make any announcement. I’m making this announcement, so that people will be more aware of the increased possibility of reproductions being passed off as original units. I.E. the possibility of fakes is increased.

Here is the link:

I believe that several people may already be making some new Apple II reproductions using these CAD files. If you are interested in having one, your best bet would be to make some queries in the more popular forums.

A CHM Youtube Video Worth Watching

Sunday, May 21st, 2017

The CHM’s youtube channel has this video, which caught my attention.

I’ve always been an advocate for the behind the scenes “little guy” that do 90% of the work that really make new products possible. My mom taught me, when I was little, that “words are cheap”. The same can be said for the new ideas that lead to breakthroughs in technology. There is always a foundation for these new ideas and they usually aren’t giant leaps, by themselves, but almost always, incremental steps in understanding.

In my mind, the hard part, isn’t coming up with the idea, but implementing it. In fact, many products are described decades before they can be implemented.

The stories on Andy Hertzfeld’s website, demonstrate the hard work that goes into implementation, as well as anything that I’ve ever seen. The thing to understand is that the effort that went into making Macintosh, isn’t unique, but rather the norm for almost all of the gadgets that we take for granted, these days. How do I know this, you may ask? Well, I’ve been involved in new product development for something like 38 years. Some of the products that I have worked on have been failures, but many of them, successful. In either case, it’s always a struggle for those involved. A rewarding struggle when it goes right, but still a struggle.

It seems Thomas Haigh understands this. I’ve ordered his book on Eniac and will write a review after I read it.

Thomas’ comments on Isaacson’s book “The Inovators”, made me pull out Isaacson’s book, “Jobs” and review the sections on Apple 1 and Apple II. I think I understand those products and what went into making them, very well. Thomas’ comments made me want to review the book for faults. I knew that Isaacson had Job’s and Wozniak soldering Apple 1’s, which was incorrect, but wondered what else I would find, if I reviewed those sections. Before I comment on what I found, I will say that I greatly respect anyone that can write such an engaging book, as I don’t have the patience or talent to do it.

Here are the mistakes I managed to find during a quick review of those sections.

  • Page 62: The guy who drew the up the circuit boards didn’t work at Atari. His name was Howard Canton, and he was an independent consultant, who did contract work for Atari and other companies in the valley.
  • Page 67: Woz and the gang didn’t solder Apple 1’s. They were wave soldered in a factory. Assembling the boards really meant stuffing the chips into the factory soldered boards. Daniel Kottke tested the boards, and if they failed, put the failing board in a “bone pile”, that Woz would debug during occasional visits to the Job’s home.
  • Though there are no real mistakes with the Apple II section, there are, in my mind, serious omissions.

  • Page 74: The real problem with the first Apple II PCB layout, was that Howard Canton, instead of doing it himself, had hired someone to do the layout, and that person did a horrible job. The layout was redone digitally, which took, if I remember right, three months.
  • The first Apple II PCB’s didn’t work, do to noise on the address lines that were connected to the DRAM. Rod Holt fixed the problem by adding termination resistors to those lines. This fix was more important than the implementation of a switching power supply. By the time the Apple II was released, switching power supplies had already been in use for 6 or 7 years. In any case, I doubt that use of a linear or switching power supply would have made a great deal of difference in the success or failure of the Apple II. Proof of this, is that the switching power supply is only mentioned in the first Apple II sales brochure, as a one liner in the last page’s technical overview section.
  • Allen Baum had a significant role in developing the monitor for the Apple II, which is not mentioned.
  • Page 84: Though Apple had venture funding, the company was on very shaky financial ground through it’s first year or two. It was not an instant success.
  • In scanning this section, I could find no mention of the Disk II, floppy disk interface. This was a critical item that enabled the success of the Apple II.
  • I understand why Isaacson, in his story, emphasized Job’s interaction with a number of significant personalities. It is a shame that the struggle to develop a new product by a team of talented engineers gets so little “ink”. I also wonder how accurate the depictions of the interactions between the significant personalities really is. It seems that, in terms of the technical stuff that I understand pretty well, Isaacson would grab a fact and elaborate upon it, kind of putting his spin on it, without doing serious fact checking.

    In any case, it’s an entertaining read, that I recommend, in spite of the errors and omissions.

    A Brief Conversation with Woz

    Thursday, May 4th, 2017

    During the Apple/Homebrew reunion, having never met him before in person, I briefly introduced myself to Woz as the guy that makes those Apple 1 clones that he always signing. He said, “nice”. He was surrounded by a crowd of people, so I let it be at that, and moved on. At least I had introduced myself.

    Later on, as I was talking to Daniel Kottke, whom I have known for several years, Woz came over and joined us. We talked about that small change that he thought could add a color to the Apple II. I mentioned that I tried to make that change, but couldn’t make it work, right. He said he knew that. I was a little surprised by this reply, since I don’t think I ever reported that I had spent time experimenting making that change, but failed to make it work well. Maybe, I had emailed him my results and then forgot about it, I don’t know.

    Woz also talked about a change he thought he could have made on the Apple II, that would have saved a chip, but required more complicated software in order to implement video support. I’m not sure what that change would be, but I’m thinking that creating an incompatible Apple II to save a chip isn’t anything I’ll be working on, at least in the near future.

    Woz talked about the video system on the Apple 1. He says he copied it from some terminal product, clearing up that point, once and for all. Part of this video system has a rather complicated state machine that implements the carriage return logic. Woz admitted to Daniel and I, that he never understood that logic. In return, I admitted that I never understood it either. Actually, I was probably being a bit humble, as I understand the concept of that circuit, but never completely understood the details of the implementation. I expect he was saying the same thing.

    Woz finally mentioned that there was one part of the Apple II design that didn’t meet timing specs of the chips. He then said that he knew it, but never told anyone. He was counting on the conservative specs of the chips involved from turning this timing violation into a real problem. I think that he was right, as I have never heard of any timing issues on the Apple II, actually causing problems.

    I wonder if Daniel and I were the first to ever hear this confession, as I don’t recall hearing about it, before. Anyway, this confession reveals some of the difficult decisions that design teams, even the best, have to deal with on a daily basis. Sometimes these sorts of decisions come back to haunt us, and sometimes they don’t. The reason that engineers sometimes hold back on reporting latent issues, is that openly reporting issues may cause endless debate within the design team and possible delays on the project. I’m sure that Woz would have reported it, if he thought it was going to be a real issue.

    By the way, I don’t advocate holding back information from your boss, I’m just saying that it does happen and why.

    Meeting Woz in person, was a real pleasure. He is a great guy, exactly the same in person as when on stage or virtually, via email.

    How I came to be at the Homebrew/Apple Reunion, LCM+Labs, 2017

    Sunday, April 16th, 2017

    A few weeks ago, I was invited to a “Homebrew/Apple reunion event” at the Living Computer Museum and Lab. Here is some of the text from the invitation.

    Living Computers: Museum + Labs, founded by Paul G. Allen, would like to invite you to a very special private event.

    We are celebrating the opening of our latest exhibit, which follows the first 20 years of Apple Computers, by throwing a party for those who were there. This is a unique opportunity to reconnect to the people, and computers, that you remember from the start of the personal computer revolution.

    I was given no additional information about who was coming or since I never worked for Apple Computers, even exactly why I was invited. However, without hesitation, I accepted the invitation, and made plans to attend.

    Fast forward a few weeks, to just a few days before the event. Someone noticed a little reported article announcing that a very special Apple 1 was going to be on display at the LCM+lab’s new Apple exhibit and brought the article to my attention. This happened to be the computer that I reported in a blog posting a few years ago, though I never updated my Apple 1 registry with this unit. I didn’t think a whole lot more about it, as I have been involved in communications with many Apple 1 owners over the years.

    I arrived in Seattle on Tuesday afternoon for the Wednesday evening event, still unsure why I was invited, and who else would be there. A small bus picked up about 8 or 9 of us from the Hotel late Wednesday afternoon to take us to the celebration. I could not identify anyone on the bus, though everyone was very friendly and in good spirits.

    When picking up my name tag, I saw an impressive number of familiar names on the tags that hadn’t yet been claimed, including Woz and Paul Allen. Anyway, I introduced myself to a number of people and had some interesting conversations, including a chat with Lāth Carlson, executive director of the museum. However, I still was unsure why I was invited. I was taking the approach of “when in Rome, act like a Roman” – in other words, I was just trying to fit in and not ask too many questions.

    After a bit, we were led through a behind the scenes tour. As we were watching the Bendix vacuum tube computer G-15 being demonstrated, someone that I didn’t recognize, saw my name tag and said “Mike Willegal is here”. The people identified themselves as the Hutmacher family and told me that they had donated the computer to the museum. The donation was kept a secret, which is why I wasn’t told anything. The Hutmacher family had asked the museum to invite me to this celebration, since, with the help of some acquaintances I had with early Apple people, I helped them verify the history of the computer and also pointed out that it belonged in a museum. The mystery of why I was there, was solved.

    The fun part of being identified by the Hutmacher family is that they made a big fuss over me, and some of them had their pictures taken with me. During all this fussing over me, Chris Espinosa, who I had never met and only could identify by the name on his badge, looked on from the background with a puzzled look on his face. I could almost see his brain working – who is this guy that they are making such a fuss over. After the Hutmacher family moved on, I introduced myself to Chris Espinosa and explained what had happened.

    Lastly, kudos to the Hutmacher family, a very special group of people, for putting a very special Apple 1 into very good hands.

    One of WOZ’s Wonder Powers…

    Thursday, April 13th, 2017

    Do to the acts of an extraordinary generous family, I was invited to a private gathering of micro-computer legends at the “Living Computer Museum” in Seattle, earlier this week. The gathering included a number of people that were involved with the Apple 1 while it was still based out of the Job’s home and others that were involved in the early days of the personal computer revolution. It was a gathering that, as long as my brain is functioning, I will never forgot. During this event, I learned several little stories and will share them in the coming days on this blog. Here is the first story.

    While several of us were admiring the original Apple 1 that will be available to visitors to the museum to use, we discussed how it was being booted with the museum staff. Inevitably, the topic turned to how WOZ used to enter the 4K of BASIC object code by typing hex codes using the Apple 1 monitor. Several of the people there, said they witnessed him do it, and confirmed his amazing prowess at data entry through a keyboard.

    Let me tell you, when I first built an Apple 1 clone, I tried to replicate the feat and gave up after screwing up a few hundred bytes worth of input. This was so difficult for me, that I found it hard to believe that it could be done. At the time, I sent an email directly to Woz to ask him about it. He responded that he did it all the time.

    I can’t find any blog post that reported this exchange. I may have made one or perhaps, I was so dubious, that I decided to file the whole episode away. Anyway, hearing directly from a couple of eye witnesses has eliminated any remaining doubt and I’m rectifying any omissions in faith by making this post.

    I can’t remember hearing about anyone else achieving this, but assume it’s possible. I’ll bet it’s not something that anyone else has done repeatedly. This is a difficult feat, and the fact that WOZ did it repeatadly makes it simply amazing.

    PS/2 Adapter Software and Hardware CAD Files Now Available for Free Download

    Monday, December 26th, 2016

    Go to my PS/2 adapter web page to find the links.

    Support will be very limited. The firmware is actually rather sophisticated for what this device does. Understand that it is completely in assembler, and if you desire to make changes, it would be best if you were familiar with coding in assembler for micro-controllers.

    Some scripts are included in the software package that are used to download the firmware, calibrate the built in RC oscillator and burn the fuses using a USB programmer called AVRdude. Fuses and EEprom must be programmed correctly or the micro-controller may not function correctly. The A version of the Atmel at tiny 2313 has not been tested. I have been using ATTINY2313V-10PU.

    The CAD program I used to create the PCB is called Osmond PCB. I have also included GERBER and Postscript files. You must accept all risk associated with creating PCBs using any of these files.

    End of an Era for Me

    Saturday, December 17th, 2016

    As look back at some of the blog postings I made during the early days of the Mimeo project, the excitement I felt, could be easily discerned. For better or worse, after nearly 7 years, that excitement is no longer there, and it’s time to move the project over to someone who has a strong passion for that landmark system.

    I’ve transitioned Mimeo 1 sales to Corey Cohen. I’m sure he will do a great job selling and supporting people interested in building reproduction Apple 1 Computers.

    Since first making them available in March of 2010, I’ve sold 167 Mimeo PCBs, the first few as part of a kit, even a few that were completely assembled and tested. I have greatly enjoyed the entire process from creating the PCBs in the first place, to fixing a few boards that customers needed help with. Especially gratifying, has been the great relationship that I have established with all the people that I have made contact with over the years. One thing that I never expected, when starting this project, was the amazing contacts I made with so many people associated with Apple during those early years.

    However, the learning part of the process, which is one of things that keeps me interested in my hobbies, has not been there over the past few years. It is time to move the sales over to Corey, who has unbelievable enthusiasm and knowledge for and about those milestone computers.


    I will continue to sell SCELBI PCBs, as I am still excited about working on that system and learning a lot, while doing it. Blog followers will know that the Oscilloscope Interface PCBs, the last SCELBI boards that need to be reproduced, will soon become available to interested parties. I have some ideas for some even more obscure reproduction vintage computer projects. However, the Oscilloscope interface must be completed, before I move on to those projects.

    Other Products

    Other products I have sold in the past, will only be continue to be sold if I have remaining inventory in stock.

    I presently have stock of the following

  • Brain Boards
  • Swift Cards
  • I am sold out of the following:

  • Apple II, rev 0 boards
  • SuperProto boards
  • PS/2 keyboard adapters.
  • Datanetics Keyboard PCB
  • The PS/2 Keyboard Adapter

    The PS/2 keyboard adapter is a little bit of a special item to me. When I had those PCBs made, because of economies of scale, I had 150 fabricated. I never thought I’d sell all of them. In the end, I sold over 140 those little dongles, using the others for a number of my own special projects. Though they probably exist, I have never heard of a PS/2 keyboard that it didn’t work with. It was designed to operate with Apple 1 and Apple II computers. As I originally hoped, people adapted the design to a number of systems beyond that. The firmware has had minor firmware features and improvements made over the years, but the basic design hasn’t changed over all these years.

    There have been a number of other PS/2 keyboard to parallel ASCII keyboard adapters designed over the years, some coming before, and inspiring my adapter. Though it could certainly be improved further, I sincerely believe my version is currently the best of the breed.

    When I get the time to add them to my web site, I will be releasing to the public domain, with no restrictions, all design files, including firmware and PCB CAD files. You will be able to do what you want with it, make copies for sale, improve it, or just study the design for your own purposes.

    Brain Boards – batch 2 now available.

    Saturday, March 5th, 2016

    I now have a batch of Brain Board kits ready to go.

    For kits sent to the US – send $59 per kit to my Paypal account (at end of this email)

    For kits sent internationally – send $59 per kit, plus $10 postage (combined shipping for all kits) to my Paypal address (at end of this email)

    For those that want to build and test the kits add $25 per kit built and tested.

    Shipment should occur within a few days, except for those that want me to build and test – expect a week or so before shipment.

    My PayPal address is: (

    Make sure you include your shipping address with Payment.

    thanks and best regards,
    Mike Willegal

    PCB and kit stocking status

    Saturday, February 27th, 2016

    I now have everything that I normally stock on hand – except SCELBI front panels.

    I was a bit behind on things, but today I shipped a few items that I owed people, so am caught up, with the exception of those SCELBI front panels.

    In addition, due to popular demand, I made a new run of Brain Board kits. I tested an example earlier in the week, and except for a bad 74LS74 IC, I found they work fine. I’ll have to go through my stock of 74LS74’s and test them before finishing putting together kits. With luck, I’ll have kits ready to ship by next weekend. Watch for an update in the next few days before sending money.

    The Great American Prob. Machine

    Thursday, January 14th, 2016

    A few days ago, I was searching through my small personal archive of Apple II floppy disk images, looking for an Apple II clone of Colosal Cave. As fate would have it, among those images, I ran across a program called “THEGREATAMERICANPROB.MACHINE”. Vaguely recalling it being a fun program from the “old” days, I started up an Apple II emulator, loaded the DSK image and ran the program. Here is a screen capture



    and a movie of the program in action.


    Just as I sort of remembered, it was a pretty cute Apple II low res color graphic animation. However, when the credits rolled, I discovered something totally unexpected. It was written by none other than Bruce Tognazzini. Tog, as he is now known, is now a respected authority on user interface design.

    Having had a brief email interaction with Tog a few years ago, and knowing he was quite approachable, I decided to send him a message. I let him know that this old work wasn’t forgotten. I figured that he would appreciate that. The response I recieved, had some quite unexpected news. Here is Tog’s reply.

    Thanks. It was when Steve Jobs saw that program that he decided to hire me. It was the first ever full-screen animation done on the Apple II.

    I sent him another message thanking him for his reply and asking him if he minded if I shared it on my blog. He responded with more details about how “THEGREATAMERICANPROBMACHINE” helped get him hired at Apple.

    Not a problem. Specifically, I took a piece of code I’d written that added a new command to Integer BASIC down to Apple to show Steve. After selling him on that, he asked me what else I had done. I showed him the Probability Machine, throwing it up on Apple’s large-screen Advent projector. He got really excited, left the room, and gathered up everyone he could find in the building. (Apple was still all in a single building in those days.) I was quite surprised it caused so much excitement; I had no idea I’d pulled off something that, at the time, was a breakthrough. A week or so later, Jef Raskin called me up and said that Steve thought we should talk. I assumed he was going to want to buy some more of my software. It turned out, he and Steve wanted me,