Archive for the ‘Apple 1’ Category

Keyboard Gizmos

Tuesday, July 15th, 2014
parallel keyboard gizmos

parallel keyboard gizmos

Here is a popouri of parallel keyboard projects that I have been involved with designing.

Not shown

  • A simple single chip AVR PS/2 to parallel keyboard adapter that I forgot about when I assembled the items for this picture.
  • At top is:

  • A reproduction Datanetics keyboard
  • At bottom, from left to right…

  • Home etched/prototype PS/2 to parallel keyboard adapter
  • Production PS/2 parallel keyboard adapter configured for Apple 1/Mimeo
  • Production PS/2 parallel keyboard adapter configured for Apple ][. The latest version firmware can also be used with other vintage computers
  • Home made Apple ][ keyboard to Apple 1/Mimeo motherboard dongle with clear switch - based on schematic at Wendel Sander's Apple 1 site
  • Production Vintage Micros Apple ][ keyboard to Apple 1/Mimeo motherboard dongle with clear switch. Similar to home made one
  • Corey Cohen’s parallel keyboard multiplexor. Automatically accepts and switches input from two different parallel keyboards to a single destination motherboard.
  • Not shown are a number of projects that I have started, but not completed (yet)

  • Datanetics replacement using modern components
  • MM5740 replacement using modern micro controller
  • And then there are the projects that never got past investigation stage.

  • ADB bus to parallel adapter
  • PS/2 Apple IIe keyboard adapter
  • It’s really hard to imagine that I have spent so much time mucking with simple parallel ASCII keyboard technology.

    Vintage Micros has Apple 1 motherboard to Apple 2 keyboard dongles available.

    Sunday, July 13th, 2014

    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

    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.

    I’ll be at the MakerFaire in Dover, NH Aug, 23rd

    Tuesday, July 1st, 2014

    I’ll have a Mimeo (Apple 1 clone) and a SCELBI 8H clone up and running and if you come, you’ll be able to see and operate them.

    MakerFaire Dover Flyer

    I hope to see you there.

    Why Does Someone Recreate the Apple 1 in Exacting Detail with Original Parts?

    Friday, May 23rd, 2014

    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.

  • First- tracking down these parts is like a scavenger hunt and can be a lot fun in itself.
  • Second- making a reproduction more like an original, raises the level of pride and satisfaction in the end result to a significant degree.
  • 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?

    Mimeo’s back in stock

    Monday, February 24th, 2014

    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 if you have any questions or interest.

    Kit and PCB status update and a question

    Saturday, February 1st, 2014
  • Coming for VCF east – SWYFT card reproduction kits – special introductory price if you join my SWYFT Card soldering Workshop – $40, drop me an email to register. Part of the proceeds goes to help support MARCH. After VCF east, price goes to $50.
  • Mimeo’s – out of stock – expect to have new batch around end of February
  • Datanetics PCBs – 1 left – rerun timing TBD
  • Brain Boards – 9 left – Note that I’m going to try move the remaining Brain Board kits over the next few months. I might even list them on ebay, to clear them out. If you want one, time to get it, is now. A rerun is not likely to be in the “cards”. I have a vague idea for an enhanced firmware board that may or may not get traction someday in the future.
  • SUPERPROTO kits – 8 left – rerun TBD – these are slow sellers and I haven’t actually made any money on these. However, I find them useful for my own purposes, so I might do another run (someday).
  • ACI kits – plentiful (currently I’m running low on PROMs, but expect I’ll be able to find another batch without too much trouble)
  • PS/2 keyboard adapter kits – plentiful
  • A2 rev 0 – ample supply
  • SCELBI 8H – I have less than 10 8H board sets remaining. I’ll make extra SRAM PCBs, when needed. Front Panels are in limited supply (less than 15, I think). TTY boards are plentiful
  • Now for the question – should I call my Apple II rev 0 reproductions Mimeo IIs, even though they came first?

    Rev 0 Repro Progress and Retro Workshop Update

    Saturday, November 30th, 2013

    Apple II rev 0 Progress
    My revision of my original reproduction, the Apple rev 0, is coming along. This morning, I did an extensive design review of the 35th revision, and only found 3 things that needed “fixing”. I’ll probably repeat the effort tomorrow on revision 36. Hopefully that review passes cleanly. If so, I’ll get quotes, pick a vendor and kick off board fabrication next week.

    Projects in the Lab
    Like usual I have a lot of other projects in progress. Some have been in progress for while, others not. Here is a snapshot of my workshop. It keeps getting more crowded as time goes on.

    My Retro Workshop

    My Retro Workshop

    My “LAB” is currently setup for checking out the SCELBI TTY card, which is interfaced to an Apple II serial card, which also supports 110 baud current loop. The hardware is working, but I have to do some software work on the Apple II side of the serial current loop connection in order to make it usable. The standard Apple drivers seem just a bit quirky,as they are tied into Apple II monitor functionality. I was hoping to get by with Apple’s standard PROM drivers, but it looks like I’m going to have write a custom driver for interfacing to the SCELBI. I’m hoping to get the IIe running such that it works just like a real TTY, perhaps eventually including emulating paper tape using floppy discs. I decided to use the IIe instead of a II or IIplus because it supports 80 column output without extra plug in cards.

    SCELBI Galaxy
    I was hoping to make a video of the SCELBI running tiny SCELBAL basic and the SCELBI Galaxy program, which I recently got running. The Galaxy program is SCELBI’s version of the Star Trek game. It was published as documented source code in the SCELBI book “Galaxy”. I had to OCR a scan of the book and then covert it to the AS8 assembler format that I prefer. This took a considerable effort, but I was able to exactly reproduce the original program. When I first went to download it into a physical reproduction 4K SCELBI 8H, I discovered that there wasn’t enough room in memory for a boot loader and the game. I had to spend a lot of time creating a second version the source code to make it fit into 4K with room for a boot loader, without altering the play of the game. This was particularly difficult as the originally published source, didn’t have labels attached to any of the messages, just hard coded addresses pointing into a huge block of characters. In order to move anything in memory, I had to convert the hard coded addresses to labels and add the label to original block of bytes. Oh yeh, there were some page boundary assumptions that I also had to deal with. It wasn’t easy. Once I get the Apple IIe TTY emulation going, I’ll definitely make the video of both the Galaxy game and tiny SCELBAL running on the 8H.

    SCELBI Webpage Update Coming
    I have an update to my 8008/SCELBI web pages coming. Right now, there is too much on my 8008/SCELBI page and I’ll break it down to a few smaller pages. One page that needs a lot of work is the SCELBI/8008 software page. I have managed to get a number of 8008 programs running, some new and others, like Galaxy, old programs that I believe haven’t been run in decades. I need to set up a dedicated software page in order to share them all, plus the cross development tools that I have used to develop them. Most 8008 software from the era will need to have I/O drivers tweaked in order to run in a particular environment, so I will need to publish source and tools. Some of the software, I didn’t develop, so I need to get permission from creators. I would also like to find time to covert my SCELBI blog posts, along with original documention into some kind of book form, as information about building a SCELBI is rather scattered around. I don’t know when or if I will get around to this, but I am motivated, as I think better documentation might help me to sell more SCELBI board sets.

    Apple IIplus

    Apple IIplus

    Apple IIplus

    At top of the first picture you can see the keyboard for an Apple II plus that I recently picked up as part of a Craig’s list transaction. My intention is to clean up and repair this Apple IIplus for resale. I think it will make a good first II plus system for someone, since it has a pretty late serial number along with an RFI board. My experience with those later systems with RFI boards is that they tend to be more reliable than earlier systems. In fact, except for some keyboard issues, this system came in working condition. As you can see by comparing the inside of the top with the rest of the case, the plastic hasn’t yellowed much, if at all, so it should clean up real nicely.




    Along with the IIplus, I picked up a TRS-80 system, with expansion chassis and floppy drive, along with documentation. It doesn’t work, but it should be a fun project to fix up. I can’t decide whether I will keep or flip it. Initially I was going to add it to my collection, but the engineering isn’t what I’m used to, so I’ve already somewhat soured on it. A friend of mine had a TRS-80 briefly, back in the 70′s, but took it back and got an Apple II. Having played with his TRS-80 briefly in the 70s, is what spurred my interest in having one, now. If I keep it, I’ll need to get a Commodore Pet in order to have one of each of the first machines of the “big three” computer manufacturers of the 70′s.

    I keep telling people that I’m not a serious collector, as I like to work on, learn about and operate these old machines. I don’t usually acquire vintage computers, just to own, which is a sign of a serious collector. However, as you can see from this blog post, I seem to continually find ways to increase my “backlog” of projects.

    Mimeo PCBs now available

    Thursday, November 7th, 2013

    I now have the latest batch of Mimeo PCBs in stock – same price as before – $150 plus shipping.

    Send an email if you need more details about ordering.

    A reproduction white 6502 … and comments on reproductions and fakes…

    Wednesday, October 30th, 2013

    The immediate reason for this post, is that an Apple 1 reproduction now sports a plastic 6502 that has been converted to look like a white ceramic 6502. Details of this conversion can be found on the retro-restore yahoo group. I plan on converting one of my own, as I’m not that excited about the price of real ones. Also be aware that many of the white ceramic 6502s that have recently come to market were pulled from interesting vintage gear, like Kim-1s or arcade games, a practice I have mixed feelings about.

    I’ve heard from several people over the years about the risk of reproduction parts and systems being sold as the real thing. As the popularity of the vintage computer hobby and value of the rare vintage systems increases, it is inevitable that new kinds of reproductions will appear.

    My position on reproduction components and systems is that they will allow people who couldn’t otherwise afford to operate the real thing to get a better understanding of this vintage technology and have some fun. The closer the reproductions are to the real thing, the more accurate the experience will be and the more we will learn about the original systems and the history of computing. Usage of reproductions instead of originals also saves wear and tear on original systems.

    A number people get great enjoyment from making a reproduction that both operates and appears as authentic as possible. This is similar to the enjoyment that skilled craftsman in other hobbies get from their efforts to make life size and scale reproductions of everything from stone tools to railroad empires. We should enjoy our hobby and marvell at the skill some of our friends, who go the extra mile to make their creations as accurate as they can.

    One of the favorite things that I have heard during a VCF event, was when one visitor commented that he never thought he would ever get to operate an Apple 1. Of course he was operating a Mimeo, but to that visitor, it didn’t matter that it was a reproduction. So reproductions can give enjoyment not only to hobbyist, but to visitors to our hobby.

    The best thing that can be done to defend ourselves from fakes, is to be made aware of the possibilities and educate ourselves as much as possible. This is one reason why I created the Apple 1 Registry. In this respect, I think the registry has been a success, as, since the registy’s creation, I am unaware of anyone trying to pass off a fake Apple 1 as real. However, be aware that some time ago, there was an attempt on eBay to pass off an Obtronix Apple 1 clone as the real thing, so I will not be surprised when it happens again.

    A beautiful Apple 1 (and more) up for Auction

    Tuesday, October 29th, 2013

    This Apple 1 motherboard is in fantastic condition for a 37 year old computer and includes most of the original add ons that you would want, including an original box and documentation. It is listed in my registry as “Framed #4″.

    There are also a few other gems for sale, including a twiggy Macintosh, a Lisa 1, a SOL 20 and an Altair. I have a catalog of the auction scheduled for November 16th and it is filled with many other interesting vintage toys, scientific instraments and more.

    I had the pleasure of meeting with the Brecker’s for a couple of hours back in August while they were on a business trip to the United States. It was very interesting to talk to them and I really wish them further success with their technology auctions.

    By the way, I need to update the registry. People have continued to fix up their Apple 1s, so I’ve got a more up to date image of one unit that received some serious love over the last few months. I also need to add couple of new Apple 1s. I forgot to add the one in the history San Jose museum during last update and another one came to my attention immediately after the last update. Finally, I figured that units that are discussed in either Tom Owad’s book “Back to the Garage”, or Bob Luther’s “The First Apple”, should have that called out in the registry listing.