The many projects floating in my head

I have so many projects in various states that I’ve decided to try off the top of my head to list them and their current status, I have 320 minutes so here goes:

1. FEZ .NETMF based NIXIE (BDC) clock written in C#
   1. Basic BCD conversion / driver code is written and working
   2. Interface to a set of NUMITRON tubes is working
   3. Internal RTC is working
   4. Network interface is functional
      1. I’ve created a mini web server that delivers the time/date via a web page
      2. I’m having issues with UDP, I can’t seem to query an NTP server
2. FEZ .NETMF based Lobby Counter using NIXIEs, written in C#
   1. Very much in the early planning stages, will use code from the BCD clock project
3. Conway’s Life sculpture, using an early plasma display, PIC16 based, written in c
   1. Electronics and programming are complete, it runs well and is really fun
   2. It plays Conway’s Life starting with a random pattern
   3. It recognizes repeating patterns up to 17 levels deep (ran out of RAM)
   4. It used an external RTC and is also a digital clock
   5. It implements Raymond Weisling’s 4 letter word algorithm from 1973 to generate and display random 4 letter words.
   6. It is menu driven and has a ton of user options.
   7. I need a case to house it, then I can call it complete.
4. S-100 Computer
   1. I have a running S-100 system that I am slowly updating.
   2. Designed and wire wrapped a 64K memory card with serial and parallel I/O, updated CP/M 1.4 for the UARTs and memory size on the card. A Centronic’s Parallel part is partially implemented using an 8255.
   3. Soldered a video card from a 30 year old kit and got it working. Wrote a custom ‘driver’ for in and built the driver into CP/M 1.4
   4. Soldered an RTC card from a 30 year old kit and got it working.
   5. Custom built a backplane and card cage for it.
   6. Custom built a linear power supply for it.
   7. I still need too:
      1. Convert from CP/M 1.4 to 2.x
      2. Get the Z-80 based CPU card I assembled running at 4MHz
      3. Convert from the TARBELL Single Density floppy controller to one that handles double density, I have a couple DD cards here, just need to patch CP/M for them.
   8. I have a number of 30 year old blank PCBs, Z-80 CPU, I/O cards, memory cards etc. that I want to stuff out and build another standalone system, I have two NOS 8-inch floppy drives waiting for this system.
   9. I have several modern design cards for it I want to get assembled
      1. Front Panel
      2. CPU card
      3. I/O card
      4. ???????
5. N8VEM Computer
   1. Basic computer up and running, boots CP/M from floppy, IDE harddisk or flashdrive.
   2. Video card working.
   3. Designed a custom sound (AY-3-8510) and speech (SPO256) card for it, lots of fun hearing it talking.
   4. Custom build a card cage for it.
   5. I started working with the graphics card project for it then got sidetracked.
   6. I have a stack of cards for it waiting to be assembled.
6. Pro-80
   1. I have one of two working example that are know in the world, I have restored it and it runs well. I want to add memory to it using the S-100 card connector built into it.
7. MARK-8 Computer
   1. I have my second set of Obtronix provided PCBs, I had to sell the first unit 1/2 assembled some time ago. I have the PCBs, an 8008 CPU and LEDs from the era it was designed. Just need to find the remaining parts and get it built.
8. Apple-1 Computer
   1. This is making excellent progress, it has my full attention. I am blogging about it as I go.
   2. About 1/3 of the sockets are soldered in
   3. I believe I have all the parts (except for the transformers) required
   4. I hope to spend a few hours working on it today (including photos)
9. Replica-1 Apple-1 Clone
   1. It is running again, the S-RAM had failed, now to lean the WOZ monitor using it.
10. Parallel ASCII keyboard
    1. I have a NOS early 1970s parallel ASCII keyboard made by Cherry. It is of the correct vintage for my APPLE-1 project.
    2. It uses RTL logic and uses negative logic (meaning the bits are inverted from what I need).
       1. I need to add an inverting latch and a latch pulse signal to it so that the Apple-1 can use it.
    3. The proper edge connector for it has been found in one of my boxes of old computer stuff, this was the last obstacle to getting this usable.
11. SCOM Status Application for Windows Phone 7
    1. I need and want to do this for work, it will help me learn how to program the phone
    2. In the very early planning stages
12. A game for Windows Phone 7
    1. Currently just a dream, thinking I will port SPIN, we’ll see….
13. LED Light bar for my CNC Mill
    1. I don’t have nearly enough light at the mill head on my mill, this is a bar with a number of high intensity LEDs that is flexible. I want to create a mount (or mounts) to hold it out of the way but in a place where the mill end, tool and material being milled are well lit.
14. CNC Mill
    1. The issues with run out on the mill end have been solved (bought a new palm router to use as a mill end).
    2. I’ve cut a new set of wooden clock gears with very acceptable results.
    3. Current issue is I need to mill parts longer then the 18 inch max length on the mill, there are several mechanical solutions. I’m however stuck in the design software as it wants all the vertices to be closed loops, how I do this and not cut the part in half has my stumped?
15. Conversion of hundreds of photos to digital format with cataloging
    1. Making slow progress, this was easier before MOM died as I was doing it for her.
16. Photos and blogs – I need to document and share everything above.
17. Windows Media Center computer
18. Ripping all my DVDs to the media center
    1. Not pirating or stealing, just making copies for convenience, I will keep the original DVDs
    2. How do I RIP HD DVDs, I have an X-Box 360 HD player and lots of HD media, I just can’t find the right software to rip them now that HD is dead.
19. HP-65 Calculator
    1. I do love this calculator, the restoration when very well, it’s beautiful. I have so many items along with it, I need to document it.
20. HP-41CV calculator – alas I should sell you for my heart has been stolen by another
    1. I have probably 100 items I need to get on EBAY and get sold
21. PIC32 – Mikroe has released the beta c compiler for you, I want to upgrade and see what cool things I can do with you. You have the power to bring multimedia, multi-touch and so many other fun things to life within the Mikroe world, these are still the best tools for the price you can find.
22. FlushList – my web idea, you are still there in my mind, someday… someday…
23. I want to dog through all the ancestry work my extended family has done, there is so much waiting for me to learn about my family, I just need to find the time.
24. Ah, my Valkyrie. I love you girl, your green and ivory paint is so beautiful. I will ride you again some day, I will wash and polish you. One day soon, you, I and Karen will ride again. The wind in my face, the woman I love pressed tight behind me.
25. The PONG project
    1. So many antique PONG chips in my stock, anyone up for a game of PONG 1975 style?
26. The Heathkit project
    1. I need to get one system fully operational, of the two I still have both still have issue
27. The Radio Shack Model IV project
    1. You my friend are complete, I have recreated as best I could the development system I built for myself in the early 80s. Now I need to use you, you can run CP/M, you should be able to help with my S-100 work.
28. A Bikers Journal – my book about two brothers finding each others, finding their way, finding a life. You have been completed for years yet you sit, unpublished. I need to take the next step with you.
29. Learning to self publish for the Kindle, I could publish my book; more important I could publish Karen’s Novels. Must learn to self publish for the Kindle.
30. Dad’s book, I need to finish reading it. I need to mail his original manuscript back to him now that I have it safely scanned into the computer.

Times up, 30 minutes, 30 items called out. I wonder how many I’ve missed? This list was created in a single session totally from the top of my head.

Assembling an Apple-1 computer – Part 1

An Apple-1 – What is that?

The Apple-1 computer is the first computer designed and sold by the company that today is known as Apple Computer. The design itself represents everything in the early microcomputer ethos. Steve Wozniak designed it for the sure pleasure of designing it; for the sure pleasure of being able to attend a meeting of an early microcomputer enthusiasts group to show off what he had created. Steve Jobs saw the potential in the humble Apple I to build a computer and to bring it to market. Today we have the Mac, the iPad, the iPhone and the iPod. All stand as direct decedents of the engineering and business savvy of the two Steve’s.

In building a clone of the original Apple-1 I am paying homage to the two Steve’s and to the early microcomputer industry that lead to the computerized world we have today.

I had the pleasure of meeting Woz several years ago and getting to chat with him for a bit. He is full of light and energy; his easy smile; the glint in his eyes; his humbleness; his willingness to reach out, shake my hand, smile a HUGE smile and ask my name has stuck with me.

Neil Breeden and Steve Wozniak

Neil Breeden and Steve Wozniak. I’m 7 foot tall resulting
in Steve looking very short next to me. In my hand is a
Replica 1 computer (emulates the Apple-1) which Woz
has just signed. It was also signed by the designer of
the Replica 1, Vince Briel. Steve and I are showing our
Nixie Tube watches, a true sign we are both technology geeks.

The Apple-1 represents what was state of the art in 1975. An 8-bit microprocessor (SY6502), 4K of RAM upgradable to 8K, use of 74xxx series TTL logic, composite video output and the use of simple PROMs to store a monitor program. A double sided printed circuit board was laid out for it. Apple sold about 200 of these systems. I can say with absolute certainty that had I been able to buy one I would have.

An original Apple-1 signed by Steve Wozniak. The picture
was taken by the author during avisit to the
Computer History Museum.

Update for the weekend of Feb-19, 2011

I’ve got a few weeks tied up in the preliminary work for this build.

• I obtained a reproduction PCB from Obtronix, I’ve studied it thoroughly, and I’ve read over the few documents to be found about the Apple-1. Obtronix supplied the blank PCBs, the rest was left up to me.
• Finding the Mimeo Apple-1 project website has been super helpful; he has also created a clone of the Apple-1 which has provided me many resources to keep this project moving.
• I’ve found sources for the hardest to find components. Some of the parts are very rare and have not been manufactured for decades. Three shipments of parts arrived last week; I am waiting for two more to arrive so I have a complete ‘hard to find’ part set.
• Many of the parts I already have in my cache of old electronics and computer parts. The SY6502, a 6821 which I can use as a replacement for the 6820 chip, the TTL logic chips, the IC sockets, many of the capacitors, all but one of the resistors.
• I found a source for 4K 4096 style DRAM chips, at $0.85 each they were a bargain. I needed 16, I ordered 20. In my personal stock I have lots of 16K, 64K and 256K DRAMs. I’ve been collecting these parts since the late 1970s, the 4K parts are older than my collection contains.
• My collection of TTL logic covers parts produced over many decades. I hope to find parts with mid 1970 date codes to help add an air of authenticity to the build. I have literally tens of thousands of TTL parts to screen to find the most appropriate ones.
• I have an open frame composite video monitor from the mid 1970s, perfect for this project.
• I recently acquired a parallel ASCII keyboard from the early 1970s, it’s NOS (New Old Stock). It will require some work to adapt for the APPLE-1.

NIXIEs, PIXIEs and Numitrons – Oh, my! – Part 2

If you missed part one please click http://neilb.wordpress.com/2007/03/10/nixies-and-pixies-and-numitrons-oh-my/ 

Let’s take a look at the anatomy of a typical NIXIE tube clock. In this part we look at NIXIE tubes and common methods to drive them.

Acknowledgements – I have provided links to several peoples web sites in this article. I thank them in advance for providing data and examples on their web sites.

NIXIE Tubes

So, let’s start with the NIXIE tubes. As they are no longer made many types are slowly become more and more rare. The B7971 tube have become very hard to find. By all appearances warehouses of some NIXIEs look to have been found in the old Soviet Union. A search for NIXIE on www.ebay.com will reveal several vendors selling tubes.

NOS or New Old Stock tubes. Many of the old Soviet tubes are what are known as NOS meaning literally that although they are old they have never been used, the net effect being they are like new.

You should be cautious of NOS tubes. It has been a common habit over the years to place a bad tube into the box the replacement came from. Sometimes these bad tubes in what look to be NOS boxes are sold as NOS. Sometimes NIXIEs are in flats that hold multiple tubes. NOS tubes in flats will all tend to be the same date code, if used tubes were placed back in the flat the Date codes tend to be mixed. Check with the seller to makes sure they are NOS.

Date codes. Most NIXIEs are marked with the manufactures name and a code that indicates when they were made. For example 7826 is most likely the 26^th week of 1978.

Used. These are tubes that have been used. NIXIE tubes have a finite life time. They fail in several ways. The filaments that form the numbers will slowly erode. Often the filament will erode depositing the eroded material on the inside of the tubes glass darkening the tube. Sometimes the filament will break rendering that digit inoperative. Multiple insertions into a tube socket can cause the seal between the tube and its pins to leak allowing the internal gases to leak out killing the tube. Tubes with flying leads (wires coming from the tube) that have been de-soldered can also leak at the wires due to mechanical or heat stress.

A good write up on cathode poisoning can be found at http://www.tube-tester.com/sites/nixie/different/cathode%20poisoning/cathode-poisoning.htm

Many of the tubes coming from the old Soviet Union are coming from ‘factory cartons’. These are typically NOS and are generally safe to buy.

Top, side or inverted side views. Some tubes are designed to be viewed from the top, others from the side of the tube, Inverted side tubes require the pins/wires to be oriented up in use.

You can find examples of these styles of tubes at http://www.tube-tester.com/sites/nixie/trade01-nixie-tubes.htm and http://www.tube-tester.com/sites/nixie/trade03-nixie-tubes.htm – More examples of tube types can be found at http://webx.dk/oz2cpu/clock/nixie-collection.htm

Specialty NIXIEs. Most NIXIEs can display the numbers 0,1,2,3,4,5,6,7,8 and 9. There are however some NIXIEs that display special characters such as +/-, or only 0 and 1. Other tubes display scientific symbols or electronic symbols. Make sure whatever you order can display the required digits for your application.

You can find examples of special character tubes at http://www.tube-tester.com/sites/nixie/trade02-nixie-tubes.htm

Invereted fives. Some tubes used an upside fire (5) for the number two (2). Personally I think this looks awful. Again, knowing what you are ordering will help you in being satisfied with tubes. This was done to make the tube cheaper to manufacture.

The packaging of the tubes is important; I’ve seen pictures of tubes where nearly every tube was broken in transit. Don’t spend big money on tubes then wimp out on the shipping costs. Check with the seller to see how they ship them and if they will replace broken tubes, most will.

Driving the tubes

NIXIE tubes require about 180 volts to work. Most modern microcontrollers and drivers chips can’t deal with this high a voltage so some kind of driver electronics are required. (Future posts will cover power supplies.)

Direct Drive – Each NIXIE tube is individually driven, this is typically the simplest to implement.

In the era of NIXIE tubes special ICs (chips) were made to drive the tubes. The 7441 and 74141 were common. The IC is passed a 4-bit Binary Coded Value using standard logic levels, the IC selects one of ten outputs, and each output is connected to one number inside the tube. Recall that ‘0’ is also a number the tube needs to display it as well so we have ten total outputs. These parts haven’t been made for decades and have become hard to obtain. However there are again old Soviet parts that fill the same function.  Searching ebay for K151Id1 will usually result in several hits for driver ships.

Data on driver chips can be found at NIXIE Driver ICs.doc

Using one driver IC per NIXIE tube implements the display portion of a direct drive NIXIE clock, a four tube clock would use four driver ICs, a six clock would use six.

Some kit designs use high voltage transistors to handle the high voltage, some use modern chips that can handle the high voltage. These tend to be the exceptions and are beyond the scope of this article.

Multiplexed Drive – Each NIXIE is turned on individually for a brief moment in sequence, this happens fast enough that the eye can’t see them flicker. It’s generally believed that by multiplexing the tubes they will have a longer life.

The same ICs as is listed above can be used. Only one IC is required for clocks with up to four tubes. Basically each NIXIE has the high voltage switched to it with the correct BCD code being sent to the driver IC.  This of course requires coordination of high voltage switches and the driver IC. Every multiplexed clock I have encountered uses a microcontroller to accomplish this, the multiplexing logic being implemented in software within the microcontroller. In a four tube multiplexed design each tube is powered up for ¼ of the display cycle time.

Clock with more than four tubes are generally multiplexed in what is known as a 2×3 scheme. Basically the first three tubes are multiplexed together while the last three tubes are separately multiplexed together. Two of the driver ICs mentioned above would be needed, one for each group of three tubes. This results in sufficient brightness as each tube is powered up 1/3 of the display cycle time. If all six tubes were multiplexed together they would only be powered up 1/6 of the cycle time, this scheme typically results in dim tubes.

Some people have been successful with 1×6 multiplexing schemes so please don’t take my advice as absolute – please see http://www.webx.dk/oz2cpu/clock/nixie-clock.htm for a great example.

More technical info on multiplexing can be found at http://www.decodesystems.com/multiplexed-nixies.html

In part 3 we will examine the Microcontroller.

NIXIEs and PIXIEs and Numitrons, Oh, my!

OK, I admit it, I’m a geek. Self taught electronics engineer, self taught programmer. I’ve worked in both industries for more years then I’d like to admit. Several years ago I came across a web site with a NIXIE Tube clock. For those of you who don’t know what a NIXIE tube is I’ll define it for you. It’s a display tube from the 1950s and 60s. It has little wires in it, formed into numbers; the glass tube is filled with neon gas. With the right voltages applied the numbers glow orange, a very satisfying orange. It’s not like the stark mono-colored red, green or orange that modern LEDs generate. This glow is earthy, organic and very satisfying to the eye. A great example of a NIXIE clock is at http://www.franktechniek.nl/NixieClock/CD81-6-V3/nixie3.htm

I found a kit on the web and ordered it, waiting for it to be delivered from the Netherlands. The designer of that kit turned out to be a great guy (http://www.franktechniek.nl/). The kit arrived, full of wonder for me. The little NIXIE tubes each felt like a precious work of art as I held them, knowing they are no longer manufactured and haven’t been for decades. I was charmed when in the middle of the assembly instructions there was a step asking me to take a break and have a cookie, the cookie having been included in the kit, a special treat all the way from the Netherlands.

Our mailman, as nice a guy as you’d ever want to meet commented on this box from the Netherlands, he’d never seen a package from there before. Today I have ordered parts and kits from people all over the world including parts from the old Soviet Union; these are surplus from the cold war era. I guess this just goes to show how small the world has become. Our mailman has now seen boxes from all over the world.

I’ve mentioned in previous posts my wife collects frog stuff, well I collect NIXIE stuff, and to a smaller extent clock stuff. I’ve built a few kits and designed and built a few clocks of my own. Driving fifty year old technology with modern electronics and software makes for a fun hobby.

I’m left wondering what the appeal of these clocks is for the group of us who collect them, who build things with them. I subscribe to the NEONIXIE group on Yahoo! Groups. There is a large collection of people (1721 at the time I wrote this) who frequent the group, from all walks of life, every ago group, and occupation. There are so many countries represented that I’ve lost count. We all have in common this one simple thing, a tube, now obsolete, no longer manufactured anywhere in the world that produces a nice satisfying orange glow. Perhaps it’s this glow that ties us together.

Visit the NEONIXIE group – http://groups.yahoo.com/group/NEONIXIE-L/

Some NIXIE clock sellers I‘ve bought from include:

·         http://www.franktechniek.nl/

·         http://www.ledsales.com.au/

·         http://www.tubehobby.com/

You can also search EBay for ‘NIXIE’, usually there are a couple hundred items listed.