Tom Pittman on HyperCard, Programming, and Operating Systems
Welcome to the first in a hopefully long and entertaining series with some of the wizards of the Macintosh programming world. Although the Mac may be the world's easiest computer for the rest of us, it has not traditionally been the easiest system to develop on. We all owe a debt to those pioneering programmers who used their time and skills to provide us with the Mac OS and so much wonderful software to run on it.
Today's interview is with Tom Pittman. Tom has a long history in the microcomputer industry. He is the co-author of a well respected text on compiler design called, appropriately enough, The Art of Compiler Design. He has taught Computer Science at Kansas State and Southwest Baptist University. In the Mac world, he is best known as the author of "CompileIt", an amazing program that allowed compilation of HyperCard scripts into super-fast machine code.
Tom's website has his bio as well as many interesting links:
Comment from Tom: "I think the Mac is great to develop on; it's just hard to develop for. What I call the 'Conservation of Complexity': If a program is easy for the user, it's hard for the programmer, and vice-versa."
Rick Lawson: Tom, thanks for agreeing to this interview. Would you please tell us how you became interested in programming?
Tom Pittman: In high school, I wanted my own computer. I collected electronic parts - 200 triode vacuum tubes - to build a computer. I didn't have a clue. I was a math major in college - that was before they had such a thing as "computer science" - but all the proofs were getting to be a drag.
The math major included one lab course in programming. I loved it. That summer I went to interview for a tech writer job in a local government laboratory; they had already hired somebody else, but they had an opening for a "mathematician". I told them that was my major, and they hired me. They really wanted a computer tech, but the pay was better for a mathematician.
Rick: What specifically what drew you to the Mac?
Tom: In grad school I was learning about operating systems and windowing environments. I even started to write my own windowing OS. To do my thesis, I needed some special arrow characters not in a daisywheel printer, but the Mac had just come out, and I knew it had software fonts, so I could create my own.
My prof told me I should try it before spending any money and loaned me his. He never got it back. It was everything I wanted in a computer. I wrote my own native-code Pascal compiler. That was when everybody else was buying a $10K Lisa to program for the Mac. I was going to write programs for the Mac, but for two years I didn't need to, because everything I wanted already existed on it.
Rick: HyperCard was really a groundbreaking program in opening up software development to the masses. On the limited hardware of the time, HyperCard was criticized as being too slow. CompileIt directly addressed this issue, as well as providing access to low level Mac ROM routines from HyperCard.
Please tell us how you conceived of CompileIt and some of its history?
Tom: My specialty is compilers. When HyperCard came out, Bill Atkinson said there would never be a HyperCard compiler. Strictly, he was right, because you can write self-modifying scripts in HyperCard, and that just can't be compiled in any reasonable way. But I figured that most of what people do can be compiled, and I could punt the rest. Besides, it would be fun to prove Atkinson wrong.
Pundits were also saying that HyperCard was too limited to do useful things. I decided to prove them wrong at the same time by writing my compiler entirely in HyperCard. I did that. I never used any other programming tool besides ResEdit (and a text editor) for any version of CompileIt, not even the first one, which I wrote completely in HyperTalk. It was incredibly slow, but it worked. Then I compiled it in itself, and it got much faster.
Around the time I got the idea of HyperCard compiling HyperCard, Macworld magazine came up with their "SuperStacks" HyperCard programming contest. CompileIt was barely functional when I submitted it, and the philistines in San Francisco didn't give it the attention I thought it deserved. By then I'd put enough effort into it that somebody mentioned me to Brian Molyneaux at Heizer Software, and he immediately saw its advantages and became my publisher. Brian was great at seeing how it could be improved.
Rick: Who were some of the more interesting users of CompileIt? How about unusual or interesting uses?
Tom: I really didn't have that much contact with the users; Brian did all that. I answered questions on the CompuServe HyperCard forum until their system software locked out text-only users like me. I did once go to an Apple Developer's Conference, and over lunch one day I happened to strike up a conversation with one of my users. I didn't know who he was until much later, when I heard of The Hitchhiker's Guide to the Galaxy. Douglas Adams was an avid CompileIt user. I also took apart the Mac version of Myst (the game); it was implemented in HyperCard, and I found one of their XCMDs had been compiled by CompileIt (I can tell from the machine code what language it was written in).
Rick: Did Apple ever approach you about integrating or bundling CompileIt with HyperCard?
Tom: Apple never understood what HyperCard was. Rumor was that they only offered it because Atkinson wanted people to use it, and if Apple didn't agree to ship it free with their computers, he would go somewhere else. They did not want somebody as smart as Atkinson working for a competitor. As soon as their "free" agreement expired, they started charging money for it, and they eventually discontinued it.
Rick: You have some fairly strong opinions on OS X. Please give us your thoughts.
Tom: I spent 20 years vigorously avoiding Unix - and failing often enough to remind me why it was a good thing to avoid. If you must use Unix, Apple's AU/X was arguably the least painful way to do it (much easier to use than OS X), but even AU/X was so bad it didn't last long.
After Apple announced their intention to replace their "aging" 17-year-old Mac OS by a "modern" 35-year-old Unix with a thick layer of pancake makeup, I tried to get some version - any version - of Unix/Linux up on any platform. For over three years I failed utterly to get anything to survive the first reboot. Even OS X crashed "kernel panic" dead on me the first day.
When I got on faculty at the university, there were gurus there who knew the Unix system well enough to get it up for me.
Unix is a system designed by geeks for geeks; it is not a system for real people.
Unix is a system designed by geeks for geeks; it is not a system for real people. The only people recommending OS X are geeks whose paid job already involved using lots of Unix computers before they ever looked at OS X.
Recall that I "are" a geek myself (PhD in computer science). But like the rest of the real world, I want my computer to help me get my job done, rather than forcing me to learn arcane commands that don't do useful things. The Mac OS gave my productivity an order of magnitude boost; everything since then (even Mac OS versions after 6) only goes backwards.
Rick: Do you think programming is an art or a science?
Tom: Some of each. The painter must know his colors and how to make perspective and light sources work; that's science, and he can't really make credible pictures without it. But nobody buys paintings by engineers. You have to be able to visualize a world that doesn't exist and then create it. As some sculptor reportedly said, "You take this block of marble and remove everything that isn't the statue."
I can teach principles of software design, but most people just go through the motions, following the recipe; they don't really get it.
Rick: Now that the software industry has matured, do you feel software can still be a force for change in the world ?
Tom: That question seems to personify software. It's a tool, not a force. People use tools to change the world. Computers - and the software that makes them work - seem pervasive today, but I think we are about where cars were 60 or 75 years ago. There is more change coming, caused by computers, but not so obviously.
Rick: What are you working on now?
Tom: A sort of super-compiler. I'm using compiler technology in natural-language translation. I have it working, sort of, but not as easy to use as HyperCard or CompileIt :-) See http://www.BibleTrans.com/ for details. The first prototype was written in HyperTalk (and compiled in CompileIt), but now I'm trying to get it up on a PC.
In my spare time I also think about finishing that windowing OS I started to write in the early 1980s. I want my Mac back. OS X is not a Mac.
Rick: Any parting thoughts?
Tom: In the spirit of HyperCard/CompileIt (and TinyBASIC before that), I wonder if it might be possible to get a Mac-like (non-Unix) OS up, perhaps building on the open-source Linux kernel but without all the Unix mistakes that make Linux unusable.
Think what would happen to Vista and Linux if that $100 computer they are working on for third-world users was as easy to use as the Mac was. Would some foundation fund development? Once we had version 1.0 working, it would acquire a life of its own. It can be done!
Rick: Tom, thanks so much for your time, and good luck in your future endeavors.
About the Interviewer
Rick Lawson is a Senior Developer specializing in Web technologies. He lives in South Carolina with his wonderful wife, son, daughter, and three cats. He has been enamored with Macs since coming across a brand new Mac Plus in college almost 20 years ago.
- Mac of the Day: Mac LC II, (1992.03.23. The LC gained 4 MB base RAM plus virtual memory thanks to its 68030 CPU.)
- Support Low End Mac
Cult of Mac
Shrine of Apple
The Mac Observer
Accelerate Your Mac
The Vintage Mac Museum
Mac Driver Museum
System 6 Heaven
System 7 Today
the pickle's Low-End Mac FAQ