The Apple /// Computer was released by Apple in 1980. It has an iconic design, and was a famous failure for Apple. They were trying to increase their share of the business of selling computers for business. The chronology is important otherwise we risk passing judgement on the decision makers at Apple with the benefit of hindsight. We should remember that Apple did got a taste of the potential of the Business market when Visicalc was only available on Apple II. This "killer app" sold alot of Apple II computers for a period of time, but by 1980 Visicalc was becoming avaliable on other platforms. The IBM PC wouldn't be out for another year (1981), and it would be several years after that before IBM PC Compatibility would emerge as a market trend. I think this context makes the design decisions around Apple III a bit more understandable. It's likely the failure of the system was due to the complexity of the system and technical problems with the computers. This system was arguably the first Apple project that didn't have Steve Wozniak at the helm, and it does feel like a system that was designed by a committee. Or maybe it just feels more corporate (by design).
Because the systems were a commercial failure they have always been rare in comparison to Apple IIs. Because they are early Apple computers they've become more desirable for collectors and more expensive to purchase but once again my retro computer friend Steve Hatle has been very generous with several parts machines. This gave me a very good shot at getting a working Apple /// system. On intake the pile of hardware looked like this...
Working my way thorough the hardware I noticed that there were two different types of main circuit boards. I started watching repair videos and downloading and reading manuals since I've never owned or even used an Apple III machine before. As is so often the case, Adrian Black came through with a really informative Apple III video. There was an earlier design and a later design for the Apple III. I had one machine with the later design and one with the earlier design as well as a spare main logic board and memory board of the older type that was quite dirty.
One of the first things I learned was that all the RAM on an Apple III is on an expansion board. The machines won't boot at all without that board installed. The older style main board has 12 Volt RAM and can go up to 128K, the newer style RAM board runs at 5 Volts and can go up too 256K. The differences are explained here, but the important point is that the RAM boards can not be swapped without changes to the motherboard!
On intake both machines were showing signs of life. I started repairs with the older machine. I went through and tested all the RAM chips one at a time. The first row must be populated by special 32K RAM chips that Apple had made for them at the time. These are prone to failure and I don't have a tester that will work with these chips so I pulled the RAM off both of the 12V RAM boards and tested using trial and error. The Apple III does have a helpful RAM diagnotic on boot, but I don't think it's a very thorough test, which I will come back to later. The second and third rows can be populated with 4116 RAMs, which I can test offline with a low cost tester from eBay, there were several bad chips that I replaced from chips I have in stock. After that, the machine would get through the diagnostics and try to boot.
Neither keyboard was complete. I was able to scavenge parts off one keyboard to get the first keyboard working. I cleaned the External and Internal Floppy Disk drives and they appear to be working good. After this the machine would boot off Floppy Disks I made from disk images on the Internet. It was very gratify to see the machine boot for the first time. I started poking around with the Apple III and learning about the operating system software (called SOS) but then put this project on hold just before Vintage Computer Festival.
During VCF Midwest I was happy to learn from Chris Tersteeg that the Apple III could boot off a Fujinet. I got one of these circuit boards from Chris that allows the Apple III ROM to be modified to auto start a smart port device. I later learned that you can make a special boot floppy that will do the same thing. The project is called SOSHDBOOT by Rob Justice. I also spent quite a bit of time experimenting with a similar project that allows the DAN II Controller to boot in the Apple III, but I ended up damaging my DAN II because I didn't notice that one of the slots on the Apple III had the end broken off. I ended up having mis-alignment of the connector pins in the slot which caused a short of some kind. I don't know what the failure mode was exactly, but I could smell that things were getting hot before I shut down, and then the card will no longer work in an Apple II. The Dan II is an open source project, so I hope to come back to that repair, but I have set that card aside for now. On the Apple III I don't need four expansion slots, so I've tapped off the damaged one for a future repair and pivoted to using the BOOTI card instead since it is also supported.
I discovered through trial and error some of the error codes for the SOSHDBOOT project which I'll share here:
BOOT ERROR C = No Smart Port Device Detected
BOOT ERROR R = Device Detected, but Not Good (One error is fragmented image files, fix here)
BOOT ERROR S = Device Detected and Drive Detected, but can't boot, (could also be fragmentation)
This project includes several Hard Drive image files pre loaded with software. As a beginner to the III I was quite excited about not having to figure out program installation, but my excitement faded when the boot up stopped with an error message:
Selector Error 0D:.PROFILE/SOS.MENU
I thought that it may have another mistake that I'd made with the software setup on the drive emulation so I used Chris T's adapter to hook up my FloppyEmu to the external Floppy Disk port and put the same disk image on that. I got the same error message. So this made me think that the problem may be with the hardware configuration, maybe I didn't have enough RAM? I looked for system requirements for the Selector III software that creates the boot menu, but I couldn't find that online.
But I wanted to work on the newer machine anyway, so I pivoted back to that and started doing more troubleshooting on the second machine. The state I had left this machine is that it would do the diagnostics and pass with a keyboard attached, but it would not boot SOS. It would boot the Confidence test disk, but it would only run for a few minutes before locking up with garbage characters on the screen.
I had used the on-board RAM diagnostics to condemn and replace several of the RAM chips in a previous troubleshooting session. The machine was passing the boot RAM diagnostics, but I decided to remove the RAM and test one at a time on the separate RAM tester again. What I found was a surprise, one of the "known good" RAM chips that I'd tested when I put the RAM in storage was the culprit, I should have been testing the replacement RAM as it went into the machine! When I replaced that, the machine was back to booting and running with it's full 256K RAM.
Now I had a machine to test the theory about the Apple III Selector III menu needing 256K RAM. This did indeed solve the problem, the Smart Port functionality works, and I have a second functional Apple III with an emulated Profile Hard Drive full of software to explore! Very exciting. Here's the machine paired with a Monitor III I had gotten with a previous Apple II purchase...
I spent a bit more time with the keyboards and a third parts keyboard from Steve. I had been told before that if the light bulb on the keyboard died, the system would not recognize the keyboard, but I forgot that till I got to the point where I needed two working keyboards. Sure enough, replacing the dead light bulbs on these two parts keyboards does allow them to be recognized by the computer, so this was another hurdle overcoming to getting the second machine back up and running.
The second "Full" Keyboard is not quite perfect, I had to make some printed labels for a couple of the keys and the Alpha Lock key is a momentary key not a toggle. The bezel around the keyboard is smashed, but other than that this is a second working Apple III machine that is somewhere between a partially completed project and a parts machine...
I did not anticipate at the start of this project that I'd be able to get two functional Apple III machines out of this lot. These machines have a bad reputation but so far my experience with them has been good. I'm going to keep the first machine setup and I'll keep poking around with it and learn more about the software. One of my next goals is to try to get a printer working.
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I was entirely an Apple // person in the 1980s. To date, I have never used an Apple ///. My sole real world encounter with the /// was in 1990. I was visiting a college friend, and we stopped at his summer job location - a small town, rural Minnesota, gas station / convenience store / auto repair shop / car wash business. At some point, we went into the cluttered back office of this business. There, on the desks, were two Apple /// systems complete with Profile hard drives. Still in use, presumably for keeping business records and bookkeeping and such.
ReplyDeleteGreat story, thanks for sharing Alan. - Steve
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