Interview With Gary Kato

By Gerald Kloos, May 2006
Prologue translation by Dieter König, August 2008

Gerald Kloos with his favourite Intellivision gameTo the left: Gerald Kloos with his favorite Intellivision game

Prologue: I still remember very well the year 1983 when I bought my Intellivision console. My first own video game system! Very soon my main interest was in the games of Imagic, whose graphics were head and shoulders above the other companies (including Mattel). Since that time I have never admired and respected a software company as much as I did Imagic.

My first Imagic game was Demon Attack … after an almost endless waiting time, because I ordered this game from the father of a good friend, who fortunately was owner of several department stores including toy sections – but unfortunately was not the fastest in individual orders for special customers. But – this should not be unmentioned – he was kind enough to give me the game for a special price, not the horrendous 149 Deutsche Mark (apprx. 75 Euro) that were usual for Imagic titles in Germany back then.

When the cartridge was finally inserted into my Intellivision console after weeks of waiting, my enthusiasm was almost boundless. I still remember how strong the seduction was to bunk off school, to get home earlier and to find out more level variants of the game. The furious graphics and playing performance of Demon Attack was the benchmark for my following video game acquirements. Significantly I played almost all Demon Attack ports in later years, until a really advanced age. Some of them I played on emulators, others on the real hardware from flea markets – just to test the other Demon Attack versions personally and to compare them. No other version was able to hold a candle to the masterpiece of Gary Kato for the Intellivision system.

During the last years I attempted several times fo track down Gary. Many questions from my youth required answers. Yesterday evening I finally succeeded in tracking him down in the USA. My questions were the same since many years – this explains (together with Gary’s friendly nature and quick replies) why by now (one day later) the answers to my questions are already existant. For me the circle closes now. Many open questions, speculations or assumptions from my youth regarding this software jewel have received definite and competent answers. Thousand thanks, Gary!

Please regard my one or two misspellings with favour. It was important for me to keep the vibes of my adolescent furiousness.

The cover of Demon Attack for the IntellivisionHow are you actually? What is a typical Gary Kato day in 2006?

I am doing fine these days. I am working for a nice small company called CrystalMedia Technology in Sunnyvale, CA. I write software modules for digital TV chipsets. I’ve been there for about a year and a half. The company is owned by a large Taiwanese company called MediaTek (they make the chipsets). The great thing about this is that CrystalMedia has a small feel without the money worries of typical small companies.

I don’t keep to a rigid schedule, which took my boss some while to get used to. It was a source of friction in the early days but he trusts me at this point, for which I am honored. A typical day is I wake up, check email, go to work, come home, check email, read or play games or watch DVDs, sleep. Probably the only thing that varies is the time all that happens. I may wake up at 5AM or 5PM. Even I don’t know.

Please tell me something about your educational-background, your profession or programming-skills which guided the way to Imagic.

When I was in Junior College, I was a Chemistry major. I walked into a Physics class one day and the teacher was talking about some stuff and on the board were strange incantations like “100 FOR I=1 TO 10”. We were studying harmonic motion and she wanted us to write programs to display on a Tektronix graphics terminal. Well, I was hooked after that. Since the graphics library for BASIC didn’t work quite right, most people stopped programming. Another fellow and I taught ourselves Fortran IV since that was what the graphics library was for. By the way, this first computer was a DEC PDP-10.

From there, I went to UC Berkeley. Unfortunately, the University and I did not seem to have the same priorities. I wanted to learn programming and they wanted me to learn all this other stuff. I stuck it out for a while, but after one class where a professor made continual mistakes explaining something to us then saying “Well, it’s all in the book” before he left the classroom, I was angry. I was paying for this education? But then those words came back to me like a gift. “It’s all in the book.” So, I bought the textbooks for the courses I wanted to take, then left the University.

Do you remember your first day at Imagic? Any anecdotes how you were introduced to the team?

Several of the main people had gotten together to form Imagic. This happened in two different places. I am not sure how they found each other. Brian Dougherty and Jim Goldberger wanted to for a company to do Intellivision games. They worked for Mattel Electronics. Bill Grubb and Dennis Koble wanted to do Atari games. They worked for Atari. They recruited talent. In the case of the Atari guy, they got Bob Smith and Rob Fulop. The only other experienced fellow they brought from Mattel was a very smart young technician named Dave Durran. For programming, Brian turned to two people working in the computer industry who he knew from his UC Berkeley days, Pat Ransil and me.

Pat was working for Intel and I was working across the street at Versatec. Pat called me up one day and we had lunch. At this time, I was also working for another start-up doing a graphics controller interface so I wasn’t too interested. I wasn’t too interested in games at that point and although I had an 8080 kit computer when I was at Berkeley, well, I had all these nifty minicomputers at work to play with so I didn’t feel the need for one at home. I also wasn’t in a hurry to leave Versatec since it was owned by Xerox, so we had ties to the legendary Xerox PARC.

As fate would have it, there was a reorganization at Verastec and my boss quit (or maybe he got fired), started this other start-up, and got me working there part-time. Again, I was honored to be chosen. His replacement and I did not get along together. So, I left for this other start-up. Well, a few weeks after that, this boss I had quit to get away from came to this start-up. So, I decided to go to Imagic.

I think there was some friction between the Atari guys and the Intellivision guys at first, mostly because they were real game designers and we weren’t. Actually, I believe this still to be the case. However, in our case we had to build our own development system while the Atari guys could buy off-the-shelf emulators.

I do remember some things from the very first days. Our first place was the second floor of a small office building in Saratoga. We were there all wide-eyed at all the space for only 9 of us and I think Bill said “Well, maybe we could rent the rest of it out”. Little did we know that we’d be crammed like sardines in a can before a year had gone by. Another thing I remember was buying the computer we were to use for Intellivision development. Having programmed at Berkeley, we all wanted a Unix system. I was put in charge of getting one. I found a small PDP-11/23 system running Unix and got a price quote. I went to Bill Grubb’s house and told him how much it was ($30,000?) and he sat down and wrote a check. Just like that. I was amazed since at Versatec you had to fill out paperwork to get something and wait for weeks to see if it got approved.

What was a typical “programmers-day” at Imagic like? What was your daily routine there?

For me, there were 3 phases to my time at Imagic (2 years). Phase one was just getting the development system started. I think this really was my favorite time. I wrote a macro cross-assembler that was used for Intellivision programming and I think was ported by others to other systems when the cross-assemblers they bought turned out to be bad. I think this was my first big C program (work at Versatec had been in Fortran and PDP-11 assembly, at the start-up was 8086 assembly). I have a my original listings for it and it is very embarrasing to read it now! This was also the time of learning the Intellivision, which was simplified as it was a commercially available chipset from General Instruments. I wrote the first demo program to be shown at the first CES we attended (but I didn’t go).

Phase Two was writing Demon Attack. Due to the differences in graphics capabilities, I couldn’t make it look exactly like the Atari version. Intellivision had more moving objects while Atari had more colors. I think at this point we didn’t have a full reverse engineering of the Intellivision Excutive ROMs (which was beautifully done by a consulting firm), so I did as much of reverse engineering as I could but also wrote my own Executive which used what routines I found myself. I used it for Demon Attack and I think Pat used it for Atlantis. I’m not sure if he switched over to the real Executive after we got the reverse engineering report. I think the real highlight for me at this point, as well as for Intellivision gamers, was when I first saw the graphics for the Demon Base. I was wandering all over the building (by now we had occupied most of the first floor) at night thinking about some programming problem. I had seen earlier Base proposals but didn’t really like any of them. When my eyes saw this, my mouth was hanging open. As soon as people started coming into work, I rushed back down and said to Michael Becker (our head Art guy who created it), “I HAVE to have this in the game!”. As for the graphics of Demon Attack, I have to say if it looks good, it was Michael’s art. If it looks clunky, it was mine.

Phase Three was a not so happy time for me. We moved to the much larger facility in Los Gatos. We upgraded from a PDP-11/23 (System III) to a VAX-11/750 (4.1 bsd). We had more programmers. Brian wanted the company to be more than just a game company, so we had a plan to port Berkeley Unix to the Data General MV series (the same type machine in the book “Soul of a New Machine”). I was really looking forward to that. However, the call of money was too strong and I was sent back to do another game. This would be a port of the arcade game called “Beezer”. I was given only 3 months to do it and failed. At that point, development stopped on Beezer. On hindsight, I should have refused to do the game in such a ridiculously short time.

Where were you located? At Los Gatos, CA? Where are you located now?

When I first moved to Silicon Valley (Santa Clara), I stayed with a friend then moved to my own apartment after a few weeks. I haven’t moved since!

Can you describe the “magic” at IMAGIC as a firm. Do you remind a special vibe or atmosphere in comparison to jobs in other firms?

Well, there was the excitement of a well-funded start-up.

An overlay of Demon Attack for the IntellivisionDo you still have some personal contact with formerly Imagic colleages?

Not really. We had some professional contact. I worked for Pat at a company called Nara Technologies for a few years. I worked for Pat and Brian at Wink Communications, but that was a very bad experience.

Please let us know about some programming projects of you before working on “Demon Attack” and after.

Before Imagic at Versatec, I worked on updating routines for their graphics package as well as updating some device drivers for various computers. At the other start-up (IAS), I worked on the firmware of an interface between IBM mainframes and a Ramtek raster graphics controller (at that time, vector graphics dominated the mainframe world).

After Imagic, I worked on an off-line graphics controller at Versatec, a Macintosh hard disk backup program as shareware, an Apple /// telecomm program sold by another company, did some software testing at Apple, routines for raster to vector conversion at Nara, wrote a Macintosh telecomm program for another company (which I don’t think they ever sold), wrote firmware for a system for people who are paralyzed from the neck down at newAbilities (which is still sold and who I still do consulting work for), attempted to port the Wink Engine to the Scientific-Atlanta 8600x, wrote a PalmOS application for myself to keep track of when stores are open/closed (since I don’t have a regular cycle, it’s something I need), and now software modules for digital TVs.

Did you have any insights to other Imagic game-projects for Intellivision? Did you lay your hands on other software titles but were not mentioned/credited by Imagic?


Do you remember working on game-concepts at Imagic that entered a beta-level but finally were never released? Do you remember working titles?

Beezer was never finished.

Do you still own some Imagic related items? Some eproms or prototype carts?

No. When I quit, I intended to go with Brian and Jim to a new start-up so we made sure to leave any intellectual property behind. It was only after I went back to Versatec that I asked Pat if I could have the cross-assembler listings as I was writing a microcode assembler at Versatec. A few years ago, an enthusiast gave me a disassembly of the Demon Attack ROMs that he had done. I have no documents on how the GI chips worked so I haven’t looked at it, but it’s nice to have.

Do you remember how you coded “Demon Attack”? Did you have a kind of development-kit for the Intellivision? Please place as many technical-background infos as possible!

Answered earlier I think.

Did you feel any pressure concerning the high reputated Atari VCS and Atari computer versions when you were programming the Intellivision version of “Demon Attack”?

The systems were so different as far as graphics and how you programmed it, that there wasn’t really any pressure to compete.

Was it your idea to implement more game-features then the “Demon Attack” versions for Atari had? For example the Pandemonium-Base, the really different looking opponents and attack-waves, the changing weapons they used etc. … was it a kind of brainstorming process in a team or all created by yourself?

The base was group thinking. I’m pretty sure I didn’t come up with that. I did come up with the different way that the demons worked. People were very open to comments from others. On the Intellivision side, we wanted to make the best games for that system. We didn’t want to limit ourselves to doing things exactly like the Atari version if it was a port. Activision seemed to have a policy of having their games look/act the same.

How did you master the Intellivision programming? I haven´t seen any other game that seemed to display so many different colours and graphic details. Until today some freaks doubt that this could be done 1982 on the Intellivision. It looks like a demo on a far superior technical system. Do you remember any specific programming problems you had to solve?

Not really. Intellivision programming was pretty straight forward. We couldn’t pull tricks like onthe Atari where the programmer had complete control for drawing the screen. The Intellivision was like two systems. During vertical blank, the two systems were connected. The CPU could change the graphics settings in the chips at this point. When vertical blank was over, the systems were isolated so we couldn’t change the graphics if we wanted to. The graphics system drew the screen and the CPU could devote time to the game. We had a very limited color palette compared to the Atari. I think we had 16 different colors but the Atari had 256.

The first screen of Demon Attack for the Intellivision

Do you know if certain game variations or additional levels were planned but dismissed due to rom limitations or cost effectivity?

ROM limitations ruled both the Atari and Intellivision side. We crammed as much as we could in every game.

The sound of “Demon Attack” seems at first sight somehow usual for space-shooters of that time. But the polyphone sound-sequence when the pandemonium base appears is really diabolic and extremely well programmed. Who did that composing-stuff?

Dave Durran did the sound programming. He was quite a remarkable guy back then. He was very young (19, 20?) and very interested in sound and music. He wrote his own music development software and worked on sound effects and music.

“Demon Attack” shows on the backcover and also in the game manual different pictures then the game really offers. The shown pictures are not better or worse… just different. It is until today not uncommon concerning time pressure etc. to show some artificial “screen-shots”. It would be great to know: were these pictures drawn by an artist or do they show an early version on a development-kit before readapting graphics because of rom-limitations or machine-performance etc.?

They were done by an artist.

I´m not quite sure if you remind it… or were ever told about it? At least some “Demon Attack”-cartridges for example the one I bought in my youth (also a second cart I bought nearly 20 years later) offered a bug. If you shot straight in the core of the pandemonium base and in that very moment when the core got hit moved your Spaceship fastly in a diagonal-direction, the screen “froze” in a vibrating-shaking-state. This effect was only interruptable via pressing reset on the console. Strangely this effect does not occur on the emulations I have tested. Did you know of this bug? I reported it to the german distributor “Harman” back in 1983 and they called me some days later and confirmed the bug I had found.

Yes, I knew about it. I never found the cause for it. It really ruined the joy of seeing people buying the game in stores. It still bothers me to this day. I suspect it has something to do with interrupts. I saw it mostly happen after lifting off to go to the Demon Base. The Base would never show up and you would drift until you hit the reset button.

Imagic titles in most cases offered superior graphics than Mattel inhouse products or the other independent producers like Parker and Activison. No software company could offer graphics on Intellivision like Imagic. “Demon Attack”, “Atlantis” and “Dracula” graphically even stand above most games that were offered for the technically superior Colecovision-System. Do you have any clue how this was achieved?

No magic on our part except perhaps for having good artists.

The strange thing (especially in comparison with other systems like Atari and outside developers like Activision for example) all these 3 Imagic games had some bugs or “problems” :-) on the Intellivision. First the one mentioned before in “Demon Attack”. “Dracula” also crashed from time to time- but not predictable. “Atlantis” strangely provided not endless attack waves. The game-manual did not mention that after mastering many waves a large purple-line!!! was moving over the gamescreen and all the remaining buildings were destroyed. There was nothing a gamer could do against this. No hint in the manual what a purple-line had to do with the “fall of Atlantis” :-) Sureley not a bug – it was programmed that way. Very frustrating way back then… when a game simply was programmed to an surprising end. All these phenomena were cross-checked at that time with the german distribution – which confirmed them in phone calls in my youth. Do you have any memories about bug-testing or an official Imagic policy how to improve the stability of gamecode. Do you remind any bug-discussions?

I think I tested the last version by myself for 15 minutes. I was under very heavy pressure from our Operations people to release. I was told there were lines in fabs waiting for my release and that we would lose them soon. I gave in to the pressure and have regretted it since. We did have some testing (I think after the Demon Attack bug was found) by bringing in kids to play. Most kids were no good as they couldn’t tell you how they happened, but one kid (a son of one of our employees) was VERY good at relating how to make a bug happen.

If I´m allowed to there is one thing (aside the bug) that I always wanted to know. The steering of the space ship is sometimes a little bit fuzzy. Way back in 1983 I thought it was a typical phenomena of the Intellivison controller. Some people loved it others hated it. But after checking “Demon Attack” again on an Emulator at my pc I become aware that the fuzzy steering is not an effect of the Intellivison controller. It seems the movement of the spaceship is not “scanned” very often through the game-code. It seems there are some little delays when you try to move your ship on the screen. Do you remember any problems with the gamecode or the Intellivsion-System in general checking moving-inputs of the player or latency in detecting player-inputs?

I don’t remember any latency. I don’t remember when I checked the controller inputs.

Sorry for bringing in financial topics :-) Did Imagic offer percentages of the sales of a game… or how were you paid?

We had a salary as well as a 2% sales bonus. I only remember getting one bonus check, but it was a big one. Not as big as the Atari guys got.

After releasing “Demon Attack” for Intellivision with your name on the package… there must have been headhunter-calls of other software brands?

Not that I knew of.

The second screen of Demon Attack for the Intellivision

What are your thoughts about leaving Imagic?

There was a huge fight to take control of the company when videogame sales dried up and Brian ended up quitting to start another company. I was planning on staying with Imagic but he persuaded me to quit and go with his. However, he planned on having the company in Berkeley and I wanted to stay in Silicon Valley, so I went back to Versatec instead.

Please share your fondest memories of your past at Imagic and also one of the sad moments.

Answered above.

Some people consider your “Demon Attack” version as one of the best games of the golden age of videogames. Sureley graphically the best Intellivision had to offer. And to me the gameplay was marvelous too. How does it feel to be reminded of a project you finished about 24 years ago?

I am happy that people have fond memories of it, despite the bug. If it weren’t for the bug, I would enjoy it more instead of being somewhat ashamed.

Epilogue: This Interview with Gary Kato received a lot of nice feedback of retro-game-lovers. Aside the fact that several people shared my point of view that Gary´s impressive game-design & programming resulted in the best “Demon Attack”-convertion of all systems, several people showed big interest in Gary´s dropped project “Beezer”.

Therefore I asked Gary again for additional information and sent him also a screenshot I was given.

It was rumored to be an Imagic related work in progress title … maybe “Beezer” or “Web wars”?

I have no idea what the screenshot is of.

Screenshot of an unknown game for the Intellivision

Gary also answered how far he got:

I did not get very far. I had the user controlled bee and the edge with tunnels. I believe the tunnels were working. I was working on making the hive walls turn. I think I got it so when a closed area was formed, the inside turned a solid color. My problem was that it was still possible to tunnel past a wall. Also for a wall to tunnel past a bee so that instead of pushing the bee along, it would pass right through. I never got to the point of adding the computer contolled bees or game mechanics like scoring.

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