I put together a 6502 memory test that can be loaded through the monitor. This is to help A2 and A1 kit builders test out their boards. Here is the link:http://www.willegal.net/appleii/6502mem.htm
Next batch of Mimeo’s is due to arrive Monday along with the first batch of PS/2-RS232 ASCII keyboard adaptors.
While waiting for the new PCBs to arrive, I’ve been working on the PS/2 RS232 to ASCII keyboard adapter manual. Currently at 14 pages, this manual seems quite long for a device with 2 chips, some connectors and a few capacitors.
I just posted a preliminary draft of it here – Since I don’t yet have production boards to test, assume that the manual may have errors, but it will give you an idea of the capabilities of the device.
Well I bit the bullet and ordered a lifetime supply of these boards. I’m sure I’ll have enough that someone will end up throwing them away when I die. Economics of these small boards is such that increasing numbers does not significantly increase cost. You can get 50% more for 15% more cost. Actually the curve is so steep that it is kind of nuts.
These boards are going to solve 2 problems for Apple 1 owners. First is finding a keyboard, which is a harder problem for many people than I originally anticipated. The second problem is loading software. The RS232 part of the interface is write only, but it will allow you to dump a program into memory using monitor commands using a PC’s application such as hyperterm. I plan on putting some programs for the Apple 1 on my website in “monitor format”, such as Apple Basic.
I’m thinking that the price for a kit will likely end up at around $39, postage paid for shipments within USA. You will need to provide a PS/2 keyboard and/or a serial interface to your PC along with the right cable.
Including the RS-232 cable adds a lot to the cost and weight of shipping, so I’m not including it as an option. Many of you may have such a cable laying around or be able to build one. Digikey sells the cable I’m using:part # AE9879-ND. I’ll post specs soon on my website.
Have you noticed that we’ve seen more Apple 1’s on eBay over the last year than A2 rev 0 boards. Who would have believed that.
I currently have 5 Apple 2 rev 0 replica motherboard kits and 1 built motherboard ready to go. Once these are gone, I’ll will not be reordering until I build a respectable wait list of 10 or 12 people. Shipments of these kits are slow, so it may take several years to build up the wait list to that kind of level.
Thinking ahead a bit, I’m considering asking for a small deposit to get on this wait list. If the list doesn’t reach critical mass within a set period of time like a year, I’d refund deposits, but keep you on the list as long as you maintain interest in obtaining one of these kits.
I’ve got a very few full kits ready to go and I’ve started shipping to folks on the wait list! Currently quantities are very limited, so I’m working through the wait list, in a first come, first serve basis. Some folks are declining this opportunity, so if you are on the wait list and haven’t received word, stand by, you may receive word soon. If I already sold you a bare board or partial kit, I’m going to give the others on the wait list a first chance, before giving you a second chance. This may not be the fairest way to go, but I’d like to give more people a chance at getting their hands on some hardware.
I need the income from these first kits to fund building a second batch of boards, so as soon as I sell the last kit from this initial set, I’ll be ordering the second batch, plus a few, easy to find, parts that I’m short of. If you don’t get a shot at a kit from the first batch, the second batch will not be far behind.
I’ve got a tentative plan on how I’m going to price partial kits. You will be asked to fill in a spreadsheet with numbers of each type of part you want to include. I’ll simply use the ratio of my costs, of the parts you choose, to my costs of an entire kit. This ratio will be multiplied by 666.66 to determine your cost. If your cost is totals less than something like $300, I’ll probably add a reasonable surcharge, since it is a lot of work to put together custom partial kits. Actually full kits are a lot of work to organize and put together, but at least I can do them in batches.
Also, I’ve got word from a reliable source that a beautiful unmodified example of an original Apple-1 is due to go up for auction soon, along with some wonderful Apple II related stuff. Among other things, is the very first production Disk ][ drive(serial number 1), prototype disk controllers and an Apple II rev 0 modified by Apple engineering into what was essentially a rev 1 engineering prototype. All this and more comes from the stash of a former member of the Apple engineering team.
Capacitors and transistors still not here, but I expect them any day.
Although I have more testing to do, I believe that the software for the PS/2 to ASCII keyboard interface is working the way I want it to. I still need to hook it back up to an Apple 2, as well as try a different keyboard(all testing to date has been with a single example). I plan on building a small batch of printed circuit boards, once I get a few of the Apple 1 kits shipped out. The Apple 1 project has been expensive and I’m going to need to recoup some of the investment before spending more money.
If you stick to acquiring old units through flea markets, word of mouth and yard sales, retro-computing doesn’t tend to be an expensive hobby. However cloning an obsolete design can get expensive, real quickly.
Now that the Apple 1 is nearly complete, my mind has been free to start revisiting some projects that are on hold. I have been looking to see if I have overlooked any internet data on the City Point and Army Line Model Railroad. So far, it looks like my previous research efforts have turned up most of what is readily available. Once the Apple 1 stuff has settled down, I plan on building an initial module in order to try out some construction techniques. I also have some thoughts about animating the layout using my Mimeo 1 as the brains. Animation of a layout in this era might be a bit different than more modern eras, since the internal combustion engine and electric power were not developed. However there was plenty of wind, steam, human and horse power available to move things around. Also the sounds of a busy wharf might make for some interesting computer controlled sound effects.
One other thing I’ve got on the drawing board, is putting together a short video podcast demonstrating operation of the keyboard interface and the Apple 1 monitor. Be forewarned, if you have subscribed to my podcast you might have a large file coming your way, in the not to distant future.
Since I didn’t get the new caps and transistors yet, I went to work on the PS/2-ASCII interface. Well except for an issue with booting up reliably, it seems to be working. I need to work on the AVR fuse settings for power up and/or add power on reset circuit.
PS2 to ASCII adaptor test setup
For the Apple-1 clear function I added a diode to the AVR’s output, similar to what is seen on the input to D15, pin 9. This is necessary because there is another TTL output that can drive this signal.
PS/2 to ASCII adaptor
The three jumpers on the right side of the board are to disable/enable the following functions.
There are several options for mapping the wiring from 16 pin dip ribbon cable to the AVR.
Look me up on AIM on Monday – “illegalwithaw” at 9:00 PM EST and join the group chat. I hope to be able to post images of the boards and let you know how they are looking.
I just received the decoupling caps, the last components I had on order. Though they will be functional, I’m not happy with them, since they are so small, unlike anything used on an original. I’ll try ordering a different decoupling cap that will hopefully look a lot more like the original, and the ones I don’t use on the prototype will go into the scrap box.
I’ve figured out the solution to the keyboard-PS/2 reconfiguration issue. I’ll put in a double row of KK type header pins. They make housings that can be individually wired and plugged in. This way, you’ll be able to make up several headers that suit your needs and just plug in the one you need. Unfortunately, it’s going to add some cost to the device, but I think it will be worth it. Here is a link to a housing as seen at digikey.
http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=649-69176-028LF
Software changes aren’t necessary for this, but I’m going to reassign outputs on the AVR, anyway, in order to clean up the PCB. I’m going to try to find time to build a prototype unit this weekend.
I spent some time last night coding up the last software features I wanted to implement for this device.
I still have to do the following before I can offer you some kits or built and tested boards.
1. test new software changes in AVR simulator
2. build a new prototype with hardware changes
3. test new software changes on new prototype with both Apple II and Apple 1
4. getting a quote on a run of production boards and cost of parts
5. figure out pricing and quantity I”ll build
6. purchasing parts and PCBs
7. writing a short instruction manual
Toughest task is building the proto board, and I have some time before the A1 PCB’s arrive in which to do that.
The original plan was to pin out the 16 pin socket for a default compatibility with the Apple II. Apple 1 users would have to cut some traces and add jumpers for the Apple 1 pin out. I am designing the board so that this will be easy to do.
As I was sitting here typing, I realized I may be able to do a soft configuration change between apple 1 and apple 2, so that no hardware cuts and jumpers would be necessary.
I guess the SW isn’t really done, after all. I’m going to have to look at what it would take to reconfigure the AVR so that cuts and jumpers become unnecessary when moving between A1 and A2. In any case, I’ll leave the option to do hardware cuts and jumpers in the HW design, in case users of other vintage gear need to configure the pinout differently.
Cameron Cooper, who has been a great asset in finding parts, is putting together a new web site called apple-1.org. We are planning some scheduled chat sessions that will be hosted from his site. The first one will be held the evening after I receive the A1 boards. Topic’s are open to Apple 1 related stuff, but I hope to post a URL to images of the PCBs boards- so this will be the first public viewing, so to speak. I’ll post the time and date for this chat session as soon as UPS gives me the date that the PCB’s will arrive. Meanwhile hop on over to Cameron’s site and get registered.
According to the status on the Advance Circuits web page, the boards are built and in the shipping department, due to ship Monday. I’m far more excited about these boards than I think I was with the rev0 boards. Could be a couple of factors at play here. First of all, this board seems to me to have been far more difficult to reverse engineer that the A2 rev 0 was. I though I would have an easier time on the A1 because of the experience of the A2rev 0, but the A1 effort turned out to be even larger. I believe that the A1 was original designed with the idea that a silk screen and possibly solder mask were expensive options, so a lot of legend information was added to the top copper layer. Also the power supply section was pretty tricky. There is more interest in this project than there was on A2 rev 0, so I think that that is adding to the excitement, as well.
While I’m waiting for the PCB and last parts to be delivered, I’ll be working on two things.
1) The A1 assembly manual.
2) The PS/2 to keyboard adaptor. I’ve decided to make a batch of these. They will default to an A2 configuration, but will easily be altered to a A1 configuration, and I’ll provide instructions. Here is what the top artwork currently looks like.
Cameron and I are also investigating a possible vendor of new parallel ASCII keyboards. This same vendor was advertising in the Hobbyist magazines the 70’s and still lists ASCII keyboards with parallel interfaces in their catalog. In fact the current keyboard appears to have the same key layout as can be seen in those 1970’s era adds. Hopefully they still stock them and the price is reasonable. Original ASCII keyboards are very, very difficult to find. The only reliable source I know of, is from the Apple II+ systems that are frequently sold on ebay.
Finally, if you are interested in a A2 rev 0. kit, remember that the price is going up on Feburary 1st.