The Original Macintosh:    2 of 12 
Scrooge McDuck
Author: Andy Hertzfeld
Date: February 1980
Characters: Burrell Smith, Andy Hertzfeld, Jef Raskin, Tom Whitney, Bob Bishop, Cliff Huston, Dick Huston
Topics: Origins, Hardware Design, Prototypes
Summary: The very first image on the very first Macintosh
this image is similar to the first
image ever displayed on a Macintosh

Burrell Smith liked to do intensive design work over the Christmas break, so the very first prototype of the very first Macintosh sprung to life early in the first month of the new decade, in January 1980. It wasn't really a stand-alone computer yet, as the prototype resided on an Apple II peripheral card, but it already contained the essential hardware elements of Jef Raskin's Macintosh dream: a Motorola 6809E microprocessor, 64K of memory, and a 256 by 256 bit-mapped graphic frame buffer, which was hooked up to a cute, tiny 7 inch black and white display. Burrell used the Apple II host to poke values into the memory of the prototype, so he could initialize the control registers and run small programs with the 6809.

I went out to lunch with Burrell a few weeks later and, knowing my appreciation for Woz-like hardware hacks, he explained the crazy way that he contrived for the Apple II to talk with the prototype. He didn't want to waste time designing and wiring up hardware to synchronize the memory of the two machines, since that wouldn't be needed by the real product. Instead, he delegated the memory synchronization to the software, requiring the Apple II to hit a special memory address to tell the prototype how many microseconds later to grab data off of the common data bus. It was weird enough to make me interested in seeing if it really worked.

By now, Burrell thought that he had the graphics running properly, but he wasn't really sure; he still needed to write some software to try it out. I told him that I'd look into it when I had some time. He gave me a copy of a handwritten page that contained the magic addresses that I'd have to use, hoping that I'd get around to it soon.

I was used to coming back to the lab at Apple after dinner, to see if anything interesting was going on and working on various extra-curricular projects. I had some spare time that night, so I got out Burrell's instructions and wrote an Apple II (6502) assembly language routine to do the necessary bit-twiddling to transfer whatever was on the Apple II's hi-res graphic display to the Mac prototype's frame-buffer, using Burrell's unusual synchronization scheme.

One of my recent side projects involved using Woz's new, one-to-one interleave floppy disk routines to make very fast slideshow disks on the Apple II. I had just made one full of Disney cartoon characters, that were scanned by Bob Bishop, one of the early Apple software magicians. Bob adored the work of Carl Barks, the Disney artist who specialized in Donald Duck, and he had scanned dozens of Barks' Donald Duck images for the Apple II. I selected an image of Scrooge McDuck sitting on top of a huge pile of money bags, blithely playing his fiddle, with a big grin on his beak. I'm not sure why I picked that one, but it seemed to be appropriate for some reason.

Even though it was starting to get late, I was dying to see if my routine was working properly, and it would be very cool to surprise Burrell when he came in the next day with a detailed image on the prototype display. But when I went to try it, I noticed that Burrell's Apple didn't have a disk controller card, so there was no way to load my program. Damn! I couldn't shut the computer down to insert the card, because I didn't know how to reinitialize the Macintosh board after power-up; Burrell hadn't left the magic incantation for that. I thought I was stuck, and would have to wait until Burrell came in tomorrow.

The only other person in the lab that evening was Cliff Huston, who saw the trouble I was having. Cliff was another early Apple employee, who was Dick Huston's (the heroic programmer who wrote the 256-byte Apple II floppy disc boot ROM) older brother and an experienced, somewhat cynical technician. I explained the situation to him and was surprised when he started to smile.

Cliff told me that he could insert a disk controller card into Burrell's Apple II with the power still on, without glitching it out, a feat that I thought was miraculous - you'd have to be incredibly quick and steady not to short-circuit any of the contacts while you were inserting it, running the risk of burning out both the Apple II and the card. But Cliff said he'd done it many times before: all that was required was the confidence that you could actually do it. So I crossed my fingers as he approached Burrell's Apple like a samurai warrior, concentrating for a few seconds before holding his breath and slamming the disk card into the slot with a quick, stacatto thrust.

I could barely make myself look, but amazingly enough Burrell's machine was still running, and the disk booted up so I could load the Scrooge McDuck image and my new conversion routine. And even more suprising, my routine actually worked the first time, displaying a crisp rendition of Uncle Scrooge fiddling away on the Mac's tiny monitor. The Apple II only had 192 scan-lines, while the embryonic Macintosh had 256, so I had some extra room at the bottom where I rendered the message "Hi Burrell!" in a nice-looking twenty-four point, proportional font.

By the time I came in the next morning, an excited Burrell had already showed the image to everyone he could find, but then he accidentally reset the prototype somehow, and didn't know how to get the image back on the screen. I loaded it again so he could show it to Tom Whitney, the engineering VP. I think Jef was pretty pleased to see his new computer start to come alive, but I don't think he was very happy about me giving the demo, since he thought I was too much of a hacker, and I wasn't supposed to be involved with his pet project.

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Since Folklore went public, some Disney collectors have tried to track down the original image, with Uncle Scrooge fiddling, but they didn't have any luck. I also asked Bob Bishop to go through his collection, but he couldn't find the image I described. So I guess it's possible that my memory is faulty here.
I thought I remembered that image of Scrooge, so I went through my old Apple slide shows. No fiddling Scrooge here, but there is a picture of Donald fiddling on Bob Bishop's Color Slide Show, along with a couple of nice pictures of Scrooge sans fiddle.
The original prototype was 6809 based? I find this interesting because my first computer, a Radio Shack TRS-80 CoCo, was (at least superficially) of a similar design. It was an 800KHz 6809E, with 16K memory (expandably to 32K directly and to 64K with a few hacks) and a display that went up to 256x192 graphics (at its highest resolution.) I always used to say that Radio Shack had the potential to blow away the Apple ][+ with this system, if only they would provide monitor output (instead of television-only) optional 80-column text and stop promoting it as a game machine. So when I just read about the initial Mac prototype card, I found it of particular interest. Obviously someone besides Radio Shack saw the benefit of the 6809 chip and also decided to use it in a home computer system (even if Apple did ultimately choose to use its 16-bit variant, the 68000.)
This is the first story that I wrote for the Folklore project, in June 2003 on the big island of Hawaii.
Why do people continue to call the 68000 a 16-bit CPU? It is a 32-bit CPU, albeit with a 16-bit data bus. The original IBM PC used the 8088, which was a 16-bit CPU with an 8-bit data bus. I've never heard anyone call the original IBM PC an 8-bit computer, however. Let's not belittle the original Mac by calling it a 16-bit computer!
800KHz? I wonder if he meant 8 Mhz. I too had a radio shack computer, but its was a TRS-80 model I. Anyways, its amazing that this Cliff guy was able to insert that card while the system was running. When I was in high school we used Apple IIe computers and I remember someone trying that with much less successful results. It is possible, but man, the timing is crucial. Cliff must have had a singular talent. I wonder though, if anyone tried that again after that incident? If so, was it successful? I guess the need to do that would be pretty limited, hehe.
This story is among my favourites of Happy New Year, Andy! Rick
It boggles my mind to know that the Mac was being designed before I had even mastered Applesoft. Also, I used to plug and unplug interface cards in my ][+ and //e for years until I burned the mousecard doing it at which point I stopped.
Excellent story. It illustrates how important a good technician is to a software developer. I am always thankful for the lab techs at work. It also made me chuckle at the great example of how precarious an environment software is often developed in.
Around 1986 I was helping a friend of mine to load a demo program on Apple ][ clones - about 20 of them. The program was on a floppy disk, but didn't require the disk to run. It turned out that he had only one disk controller card working and we had to put the card in a computer, turn it on, load the program, run it and then pull the card out and move to the next computer. Only one froze after we pulled the card, but we put the card again and re-loaded the program. Everything worked fine on all computers.
TRS-80 was all 8bit and 4Mhz Z80 straightforward. My bachelor project was 1)TRS-80 (lol) 2)Pascal and 3)mnemonic code all in one. Used the supervisor @SVR routines and used native code for moving graphics. The was an Atari st doodle trying to show off alas his (finer in resolution) graphics were painstakingly slow....
Doubtful anyone but me is reading this after YEARS of silence but oh well...the 68K is a hybrid 16/32-bit design. Often it's quoted as a 16-bit MPU because of the 16-bit ALU. Also, having an 16-bit EXTERNAL data bus also lends itself to being labeled 16-bit. Even though, I believe, it's 32-bit internally. @Drew Page: There were no 8-MHz 8-bit computers in the early 80's. 800-KHz was not uncommon. There were a few computers running < 1-MHz. Also, the TRS-80 Model 1 ran at 1.774-MHz. Not all Z80 based computers ran at 4-MHz.