Revolution in the Valley: The Insanely Great Story of How the Mac Was Made (8 page)

To synchronize with the video, Burrell had me fill the Apple II's frame buffer so the low bit was on most of the time, but set off at the end of the last scan line. I wrote a routine to sit in a tight loop, reading the latch. When the low bit changed, we would know the vertical blanking interval had just begun.

The Apple II wasn't fast enough to keep up with its own frame buffer. A new byte of video data flew by every microsecond, which was only one processor cycle. It took at least 10 processor cycles to iterate through a loop, so we ran the risk of never seeing the low bit change. Burrell had a way around this, though - if the loop time was relatively prime to the display frequency, it eventually had to slip into place. I wrote a 17 microsecond loop that fit the bill, and we were delighted to see it work perfectly.

Bill Atkinson had told Steve that you couldn't pull off a decent graphical user interface on the Apple II because of the weakness of its 6502 processor and the complexity of Woz's convoluted frame buffer. But, after a little more work on the software, we had a cool little GUI for the Apple II, with a proportional text word processor, in the summer of 1981. We thought that we had had a potentially valuable product on our hands.

We were reluctant to show it to Steve, knowing that he would want to commandeer it, but he heard about it from someone and demanded to see it. We showed it to him, and, unfortunately, he loved it. But he also insisted that Apple owned all the rights to it, even though we had developed it in our spare time.

Bill Budge's MousePaint

Steve couldn't insist that Apple owned all of it, because Bill Budge wasn't an Apple employee at the time. But Steve could claim complete ownership of the interface card, which he said was developed with Apple resources. Burrell and I were pretty upset, because we did it on our own time and thought that we should be compensated, but it's really hard to argue with Steve, especially about money.

We ended up turning over Burrell's design to the Apple II division, but they didn't think the Apple II could deal with interrupts properly (even though we had demonstrated that it could), so they added tons of hardware and ended up with more than a dozen chips. Steve made a deal with Bill Budge that eventually resulted in MousePaint, a MacPaint clone for the Apple II which was bundled with the mouse card. Burrell and I got over it quickly, but a bit of bitterness lingered, and the whole episode whetted our appetites for eventually working on our own.

Diagnostic Port

by Andy Hertzfeld in July 1981

Expandability, or the lack thereof, was far and away the most controversial aspect of the original Macintosh hardware design. Apple co-founder Steve Wozniak was a strong believer in hardware expandability, and he endowed the Apple II with luxurious expandability in the form of seven built-in slots for peripheral cards, configured in a clever architecture that allowed each card to incorporate built-in software on its own ROM chip. This flexibility allowed the Apple II to be adapted to a wider range of applications, and quickly spawned a thriving third-party hardware industry.

But Jef Raskin had a very different point of view. He thought that slots were inherently complex, and were one of the obstacles holding back personal computers from reaching a wider audience. He thought that hardware expandability made it more difficult for third party software writers since they couldn't rely on the consistency of the underlying hardware. His Macintosh vision had Apple cranking out millions of identical, easy to use, low cost appliance computers and since hardware expandability would add significant cost and complexity it was therefore avoided.

Apple's other co-founder, Steve Jobs, didn't agree with Jef about many things, but they both felt the same way about hardware expandability: it was a bug instead of a feature. Steve was reportedly against having slots in the Apple II back in the days of yore, and felt even stronger about slots for the Mac. He decreed that the Macintosh would remain perpetually bereft of slots, enclosed in a tightly sealed case, with only the limited expandability of the two serial ports.

Mac hardware designer Burrell Smith and his assistant Brian Howard understood Steve's rationale, but they felt differently about the proper course of action. Burrell had already watched the Macintosh's hopelessly optimistic schedule start to slip indefinitely, and he was unable to predict when the Mac's pioneering software would be finished, if ever. He was afraid that Moore's Law would make his delayed hardware obsolete before it ever came to market. He thought it was prudent to build in as much flexibility as possible, as long as it didn't cost too much.

Burrell decided to add a single, simple slot to his Macintosh design, which made the processor's bus accessible to peripherals, that wouldn't cost very much, especially if it wasn't used. He worked out the details and proposed it at the weekly staff meeting, but Steve immediately nixed his proposal, stating that there was no way that the Mac would even have a single slot.

But Burrell was not that easily thwarted. He realized that the Mac was never going to have something called a slot, but perhaps the same functionality could be called something else. After talking it over with Brian, they decided to start calling it the "diagnostic port" instead of a slot, arguing that it would save money during manufacturing if testing devices could access the processor bus to diagnose manufacturing errors. They didn't mention that the same port would also provide the functionality of a slot.

This was received positively at first, but after a couple weeks, engineering manager Rod Holt caught on to what was happening, probably aided by occasional giggles when the diagnostic port was mentioned. "That things really a slot, right? You're trying to sneak in a slot!", Rod finally accused us at the next engineering meeting. "Well, that's not going to happen!"

Even though the diagnostic port was scuttled, it wasn't the last attempt at surreptitious hardware expandability. When the Mac digital board was redesigned for the last time in August 1982, the next generation of RAM chips was already on the horizon. The Mac used 16 64Kbit RAM chips, giving it 128K of memory. The next generation chip was 256Kbits, giving us 512K bytes instead, which made a huge difference.

Burrell was afraid the 128Kbyte Mac would seem inadequate soon after launch, and there were no slots for the user to add RAM. He realized that he could support 256Kbit RAM chips simply by routing a few extra lines on the PC board, allowing adventurous people who knew how to wield a soldering gun to replace their RAM chips with the newer generation. The extra lines would only cost pennies to add.

But once again, Steve Jobs objected, because he didn't like the idea of customers mucking with the innards of their computer. He would also rather have them buy a new 512K Mac instead of them buying more RAM from a third-party. But this time Burrell prevailed, because the change was so minimal. He just left it in there and no one bothered to mention it to Steve, much to the eventual benefit of customers, who didn't have to buy a whole new Mac to expand their memory.

Shut Up!

by Andy Hertzfeld in July 1981

This movie had a scene
based on this story

Apple had already learned the value of having a thriving third party software market with the Apple II, whose sales increased more than ten-fold when Visicalc, developed by a tiny company called Software Arts, caught on in the business market. The Macintosh intended to replicate the success of the Apple II as an industry standard platform, so it was very important to bring third party developers into the picture as soon as possible.

Microsoft was an obvious choice for one of the first companies for us to talk to. Both companies were started around the same time during the infancy of the personal computer industry, and they already had a business relationship, since Apple licensed Microsoft's Applesoft Basic for the Apple II. Bill Gates and Steve Jobs were born in the same year and shared a similar vision for the potential of personal computers. Each one thought he was smarter than the other one, but Steve generally treated Bill as someone who was slightly inferior, especially in matters of taste and style. Bill looked down on Steve because he couldn't actually program.

Steve had mentioned the Macintosh project to Bill at an industry conference in April, which led to a meeting in Seattle in June, where Steve spun an intriguing vision of pumping out Macintoshes by the millions in an automated factory. The plan was for Microsoft to develop a series of applications for the Macintosh, to be ready at launch. Things went well enough to schedule a meeting in Cupertino in July, where we promised a demo of the actual machine.

Unfortunately, there was one small snag. We were using the Lisa as the development machine for writing the software for Macintosh, and we hadn't yet reached the point where the Macintosh could run stand-alone. The Macintosh needed to be hooked up to a Lisa, in order to download software from it. But the Lisa group was writing all of its own applications for Lisa and didn't want Microsoft to see a Lisa. They made us promise that we wouldn't let Microsoft see the Lisa.

We finally came up with a solution where we'd use a twenty-five foot cable and keep the Lisa in a different room that the Microsoft guys weren't allowed to enter. I would start up the programs on the Lisa in the other room, and Bud Tribble would operate the Macintosh. I would usually run into the main room to see their reaction.

Bill Gates showed up in the early afternoon with three other colleagues: Charles Simonyi, who had recently joined Microsoft from Xerox PARC, Jeff Harbers, who would manage the Macintosh development team, and Mark Matthews, who was to be the technical lead on the project. They crowded around the prototype, and we started to run our various demos for them, with Steve doing most of the talking.

You could tell that Bill Gates was not a very good listener - he couldn't bear to have anyone explain how something worked to him - he had to leap ahead instead and guess about how he thought it would work.

We showed him how the Macintosh mouse cursor moved smoothly, in a flicker-free fashion.

"What kind of hardware do you use to draw the cursor?", he asked. Many current personal computers had special hardware to draw small bitmaps called "sprites", and he thought we might be doing something similar.

Of course, the Macintosh didn't use any special hardware at all. It did everything in software, which was more flexible anyway, during the vertical blanking interval to eliminate the possibility of flicker. In fact, Burrell and I had recently gotten a mouse to run smoothly on an Apple II, using a similar technique (see
apple ii mouse card
).

"We don't have any special hardware for it!" I blurted out, probably with a proud sneer in my voice. "In fact..." I was about to mention that we got it running on an Apple II, which had one tenth the processing horsepower of a Macintosh, when Steve guessed what I was about to say.

"Shut up!", he yelled as loud as he could, looking directly at me. He yelled it again, possibly trying to drown me out in case I kept on going. But I understood what he wanted, changing what I was going to say, "In fact, doing it in software is better anyway".

The rest of the demo went pretty well, and both teams shared their excitement about how the Macintosh was going to take the industry to another level. We went out to dinner at a fancy restaurant in Los Gatos to celebrate working together, and we agreed to a framework of a deal where we would give them a stand-alone Mac prototype to develop with in the fall. We were very excited to be working with a third-party company that seemed to understand and appreciate what we were doing.

PC Board Esthetics

by Andy Hertzfeld in July 1981