Huston Stories – Apple 1 Notes

In March 2010 Cliff and Dick Huston sold some early Apple artifacts on eBay. These were the stories behind the Artifacts and contained a lot of interesting Apple history.

Disk II Interface Card Prototype

Hand Wired Woz Disk Controller

Back Story:

The founders of Apple knew that one of the keys to long term success was Customer Support. In the beginning that meant Steve Wozniak took customer phone calls to help in any way he could with the Apple 1. With the launch of the Apple II, everyone in engineering (and some of the production line technicians) took calls… but most Apple 1 questions still had to be taken by Woz. It was decided that to best support the Apple 1 owners the easiest thing to do was convert them to Apple II owners. Apple offered a trade-in deal to Apple 1 owners: trade in the Apple 1 for an Apple II (by late 1978 the offer also included a Disk Drive!). Most were traded in. This freed Woz from phone duties, rewarded early Apple adopters with a more capable computer, and allowed Apple to fulfill its commitment to great Customer Service.

Cliff dropped into Steve Jobs’ office one day and couldn’t help but notice the huge pile of Apple 1 boards – those that had been traded-in for the Apple II. “What are you going to do with those?”, Cliff asked. Steve told him that they were to be destroyed. “Mind if I take one… Oh! And one for my brother?”, Cliff asked. Steve reached into the pile and pulled out two boards and handed them to Cliff. Many people around Apple were amused and asked, “Why would you want one of those?” “It’s history,” was the reply, “just history.”

Though hundreds of Apple 1 computers were sold, the trade-in deal reduced the population to the few that exist today. This is one that that got a last minute reprieve from the band-saw death pile!
About the Sellers:

Brothers Dick and Cliff Huston were early Apple engineers, employee numbers 25 and 27 respectively, from late 1977 to mid 1984. They were there to celebrate when Apple shipped 100 computers in a single month. Working along side Woz, both were involved with the creation of the Apple II disk drive – Cliff designed the analog board in the drive, while Dick wrote the 13-sector “boot” ROM and fixed bugs in DOS. They also contributed to other early peripheral products, including the printer card(s), high speed serial card, and graphics tablet. Dick worked on DOS 3.2, Apple III SOS, ProFile hard disk, ProDOS, and Apple IIc. While working at Apple’s Disk Division, Cliff “moonlighted” with the Macintosh group to integrate the Sony 3.5″ floppy drive into the Mac design (have you ever seen a Macintosh with a 5.25″ Twiggy drive? – they existed).

After leaving Apple, the brothers teamed up with other ex-Apple employees to found a company called “The Engineering Department, Inc.”, also known as TED. The President and CTO of TED was Wendell Sander (Apple employee #16), who had done the digital design of many Apple peripheral products, cleanup of the Apple II design, the “Integrated Woz Machine” (IWM) disk controller chip, the Apple III, and many other projects. TED continued working with Apple as an outside contractor, producing prototypes such as Apple’s first ARM-based project (the ARM was used later in Newton), chip designs such as the SWIM disk controller (“Sander-Wozniak Integrated Machine”, not “Super-Wozniak Integrated Machine” as reported!), and support for Apple projects such as the Apple IIc-plus (TED integrated the 3.5″ floppy disk). TED also design ed(hardware and software) “Little Blue”, better known as Applied Engineering’s PC-Transporter fpr Apple IIe and Apple IIGS.

Dick returned to Apple to work in Newton group from 1994 to 1998. He worked on the Newton Connection Kit application and later on the Newton OS for the MP120/130 and MP2000/2100 series of Newtons.

Apple /// Wirewrap

The Apple II was a big hit in the marketplace. What would Apple do next? The advanced technology group was working on ideas for a graphical workstation, which would later be known as Lisa, but introduction of that product was still years away. Steve Wozniak was working on a next generation Apple II design (called “Annie”) that may or may not replace the Apple II… but it would require custom chips to meet cost reduction targets (- this was the beginning of what became the Apple IIe and IIc).

In the meantime, how about a more powerful and professional version of the Apple II? Originally conceived to have “backward compatibility” with the Apple II, the Apple III could have much more RAM, built-in floppy disk and other peripheral interfaces, 80 column display and advanced graphics, and a faster processor. It should be expandable, too, to allow addition of hard drives and advanced peripherals such as a graphics tablet. To manage all of these possibilities, a new Operating System (OS) would also be needed.

Wendell Sander took on the Apple III project (called “Sara”) with the understanding that the design would be confined to discrete off-the-shelf chips and a very short development schedule. To get the software effort underway as quickly as possible, it was decided that multiple wire-wrap prototypes would be built even as the design was evolving. Four wire-wrap prototypes were built, the first two suffering much of the rewiring needed during its evolution. All of that point-to-point wiring of the first two was done by Daniel Kottke, a superb technician who had escaped the production line to become Wendell’s right hand in the engineering lab (B.T.W. he also did much of the engineering prototype work on the original Macintosh!). After the design settled, the second two (“WW3” and “WW4”) were contracted out to Adom Moutifian and his amazing team at Twin Industries.

Only 2 of 4 are known to have survived (“WW1” is in the possession of Daniel Kottke). Offered here is “WW4”, one of the two prototypes given to the Sara OS team (Bob Etheredge, Tom Root, and Dick Huston) for software development. The boards worked very well, allowing a significant head start of the OS software, and helping to keep the Apple III project from going too far over the original schedule. The prototypes were naturally abandoned when printed circuit boards became available…

Board Revs 0 to 4

The Apple II motherboard rapidly evolved over its first year of production. To correct errors, improve timing, add features, and to make a single board that would serve for world wide markets. The changes were small, but important. Such changes established the focus at Apple on high quality that helped make Apple famous.

Instead of producing specific analog signals to generate composite color video, like everyone else did, Steve Wozniak recognized that most TVs and color monitors could be “fooled” by a digitally shifted timing to produce color. This insight allowed for a design that would produce the desired result, but with a small fraction of the circuitry needed for conventional design. The original design produced 60 Hz. video, but could not produce 50 Hz. video needed for world markets. The primary focus of the first motherboard revision, done in early 1978, was to provide the ability to produce 50 Hz. video. Revisions two and three made small refinements and revision four removed the memory jumper select blocks.

There was no part number on the Revision 0 board. It just was the “motherboard”; Apple didn’t have a part numbering system when the board was designed. This is the original production circuit design layout and although it was the ‘vision’ of the Apple II, it was called ‘Revision 0’ by the engineers to distinguish it from subsequent board revisions.

     Substantial changes were made between Revisions 0 and 1: Timing, 6 color HiRez, 50/60Hz video operation, and a cleaner layout were addressed. It is unclear (to us) whether both Revision 1 (part number 820-0001-01) and Revision 2 (part number 820-0001-02) actually shipped – but certainly one of the two did in large quantities until Revision 4.

     Revision 3, part number 820-0001-04, has gold plated traces and was physically marked “Rev 04” at the insistence of Engineering VP Rod Holt, who objected to counting from zero! There never was a part number 820-0001-03 for the same reason. Revision 3 (AKA “Rev 04”) was never put into production, but rumor has it one was stuffed for Woz.

Revision 4 was the next significant change: minimum system became 16K memory and this eliminated the RAM configuration jumper blocks. The change was important enough that it was given a new major part number: 820-0014 (with no revision level on this engineering sample). The production part number became 820-0014-01: Rod finally had his way.

The standard format for Schematics at Apple also went through some revisions, as is evidenced by the three included in this package. They are dated 16-Sept-77, 7-5-78 (5-July-78), and 1-26-79 (26-Jan-79).

Offered here are unstuffed engineering samples of the first 5 revisions of the Apple II motherboard with 3 sets of schematics.

Disk Analog Board

Steve Wozniak (“Woz”) is famous for his creation of the Apple II computer, but he is equally admired for his clever design of the Disk II controller card. Less fanfare is given a second circuit board that was needed for the Disk II product: the Analog board housed within the Disk II drive case, designed by Rod Holt (Employee #5) and Cliff Huston.

Woz reduced the Disk II controller to eight chips vs. the standard S100 controller board’s 40 or so – a tough act to follow. The standard Shugart SA400 analog read/write board was around 18 chips, so to meet the Woz magic-act the Apple analog read/write board needed to be 3 or 4 chips.

Luckily, Motorola had announced a new integrated floppy disk read chip that would help – the problem was getting some samples and making them play with very little documentation. After many phone calls, Motorola said they would like to help, but all the prototype chips had been sent out to the ‘big guys’ and we’d have to wait until they got their first production run packaged (3-4 months).

Rod Holt, VP of Engineering at Apple, told the Motorola sales guy that having to wait was OK, but asked if he could get contact information for one of the project engineers “to get a head start on doing a design.” Knowing how engineers think, Rod contacted the Motorola engineer. After about 40 minutes of discussion, the engineer told Rod that, “yes,” he did have some of the prototype chips in his desk and, “sure,” he could send some of them to Apple. With that, the game was on!

The final design of the Apple Disk II analog board used four chips, which didn’t beat Woz’s chip ratio, but it was in the ball park. Apple shipped the first disk drive to use the Motorola MC3470 floppy disk read chip – the ‘big guys’ were still thinking about it.

Offered here is an assembled engineering prototype (from first batch of 10) of the Disk II analog board, made from the taped-out design by Cliff Huston. It is unknown how many such boards exist today… most were used in engineering and testing. The board design required minor modifications (see photo of backside), and, with the addition of solder mask and component marking silk-screen, was put into production.

Disk II Interface Card Prototype

After the first hand wired prototypes were completed (and running), there was an informal contest between Woz and Cliff. They both had to “tape-out” their boards using light tables, plastic sheets, and adhesive tape. Woz had a slight advantage in that he could put circuit traces on both sides of the board everywhere. Cliff had only one side of the board to work with on half of the lay-out because half of the second side was covered with a “ground plain” to shield the drive’s read/write head from electronic noise.

Woz declared victory, showing Cliff the results. “Eeewhew,” cried Cliff with a wry smile, “look at all those vias – did you think you were making cheese?!” Woz reacted by redesigning his state machine code (to shift pins around) and re-taping his board, resulting in a much cleaner layout with fewer through hole vias! Woz still finished a couple of hours before Cliff, but Cliff didn’t mind… it was all in the spirit of making the best products possible.

Offered here is a bare Disk II Interface board engineering prototype first batch PCB (10 boards), made from the taped-out design by Woz. It is unknown how many such boards exist today… most were used in engineering and testing. The board design required modification (moving disk connector traces to the back of the board), and with the addition of solder mask and component marking silk-screen, was put into production. Included in the offering, for comparison, is a second bare controller board that represents the design as it was put into production.
Disk SN1

Disk II Serial #1

Steve Wozniak (“Woz”) is famous for his creation of the Apple II computer, but he is equally admired for his clever design of the Disk II controller card. Another piece needed for the Disk II product was, of course, a disk drive which was manufactured by Shugart Associates.

At the time Shugart’s 5 1/4″ floppy disk drive was the model SA400, to which Steve Jobs objected, because it cost too much and had too much un-needed ‘junk’. Shugart said fine, tell us what ‘junk’ you don’t want and we’ll give you a price on that. The ‘junk’ that was expensive was the read/write electronics, the head load solenoid, the track zero sensor and the index hole sensor. Shugart was amused, but said OK we’ll call it the SA390 and sold Apple 25 ‘prototype’ SA390 drives for development.

The first drive that successfully played with Woz’s controller was a modified SA400 using the Shugart electronics. When the first prototype of the Apple analog board was done, the board was used with the modified SA400 (replacing the Shugart electronics) and all was well. The plot thickened when using the ‘prototype’ SA390 drives: most worked fine (with some adjustments), but others were not playing nice at all. The solution was to optimize the analog electronics, tighten up the drive adjustment procedures and build some test fixtures to make adjustments reasonable to do in production.

Later, when Apple went back to Shugart to place production orders, one of their engineers admitted that the 25 ‘prototypes’ had come from their bad SA400 drive pile. He was surprised that any of them were made to work! Apple was suppose to beat their heads against the wall, give up and then come back to Shugart to buy the more expensive SA400. The net result was that the new SA390 drives sailed through Apple’s production line with very few problems and proved more reliable than Shugart’s SA400 in the field.

When the first Disk II came off the assembly line, it was snatched up by Apple’s President: Mike Scott (“Scotty”). Scotty awarded Drive #1 to Cliff, recognizing that without the engineering follow-through that Cliff provided (by doing the grunt work of documenting procedures and providing production test fixtures) the Disk II would have been more expensive to build, slower to ship and less reliable in the field. Wendell Sander received Drive #2 for finding and correcting a timing error in the controller’s state machine (What? Woz made a mistake?).

The availability of a floppy disk drive for the Apple II changed the market perception of Apple II from a hobbyist machine to personal computer. It was perhaps the most important turning point in Apple’s history because it made Apple a real and serious contender in the marketplace. Without the Disk II, who knows? Apple itself might have become (unknown) history like so many others.

Offered here is THE very first Disk II off the Apple assembly line – serial number 00001.

Hand Wired Woz Disk Controller

Imagine owning Tesla’s first coil, or Edison’s first working light bulb, or Wozniak’s first disk controller… Alright, alright, Wozniak didn’t invent the Disk Drive, but he did make history none-the-less.

Steve Wozniak (Woz) had seen Floppy Disk Controller boards for S100 machines. The contained close to 40 chips on boards that were more than twice as big as anything that would fit inside an Apple II. Like the Apple II itself, for a disk controller Woz focused on what was needed to do the job, not on the way everyone did it. Sometime in his pondering he hit upon the idea of substituting a single 8 bit ROM for tracking and reacting to the states a disk controller went through to decode the bit stream from the disk drive. He knew the use of a “State Machine” in the form of a ROM would eliminate a dozen or more of the discrete chips on a standard controller. After further refinements he reduced the chip count to just 9 (actually 8, since the two 555 timers would be combined into a single 556), including both State Machine and Boot ROMs. But would it really work?

Not only did it work, other opportunities became possible. Using a modified Shugart SA400 Disk Drive, Woz immediately was able to increase frequency modulation (“FM”) encoding from 9 sectors per track to 10… an 11% increase in storage per diskette. Then Woz realized that he could discard FM encoding in favor of various group code recording (“GCR”) schemes without increasing the number of bits actually written to the disk. He quickly pushed the storage density from 10 sectors per track to 11, 12, and finally 13 sectors per track, delivering almost 45% more storage per disk. The 13 sector format required a lookup table and very clever programming, but that was a small price to pay for such increased storage. [A year or so after the shipment of the Disk II, Woz came up with another encoding scheme to deliver 16 sectors per track… but that’s another story!]

Offered here is THE first breadboard prototype of the Apple Disk II controller, hand wired by Woz. The board was used by Woz in developing the various encoding schemes until a printed circuit board became available in May 1978. It is unknown which encoding scheme was last embodied in the State Machine ROM, but all were capable of decoding FM. The Boot ROM is missing, if one was ever actually used in this card. The board has not been tested for functionality.

Upon seeing this board recently, Woz immediately recognized it (with a “Wow”) by the point to point wiring on the back. Woz took great pride in avoiding wire-wrap, preferring a cleaner looking point to point soldering on his prototypes.

In the long run, this may become more historically significant (as an artifact) than any other Apple item offered from our collection (even the Apple 1). Like Tesla’s first coil, Edison’s first…

Newton Keyboard

Here’s a curious thing – a keyboard without labeling on the keys. It’s a prototype that was kicking around the engineering offices that I found amusing because, to this day, I have to LOOK to see what I’m typing. [-Dick].

Offered here is a prototype of the Newton Message Pad add-on keyboard. The keyboard would work with any Newton with OS 2.0 or greater, but was primarily intended to be used with the MP2000/2100 series. This one is among the first produced, as evidenced by the lack of labeling on the keys.