Insider Stories

Dave Theurer

Recently found an old message from 1989 where Dave Theurer talks about I, Robot. I don't recall where I originally got this from, usenet RGVAC maybe?

I was the programmer/game designer/artist/sound person on it, and Dave Sherman was the hardware designer/microcode programmer. It's hard to remember much about the game since we finished it way back in 1984 and have done several others since then.


6809 processor: game program, sounds, slave processor feeding and control, passing of hierarchical 3D object descriptions to math box, control of "camera" (viewpoint) and light sources, object clipping, sorting (pseudo z- buffering) and collision, double buffer management, memory management, sound creation (with the help of Atari 800 pokey chips), etc.

"math box" processor: 2901 based microcode for transformations and low level display list creation. Also handled creation of display list for terrain.  Does matrix multiply in 50 microseconds.

Video processor: TTL based; converted low level display list (points, vectors, and polygons) to video.


Alphanumeric stamps overlay.

256 wide x 240 height x 6 bits deep (64 colors)

However, due to a hardware trick, effective horizontal resolution was increased to 512.

Color registers: 4 bits each for red, green, blue and luminance (16 total).


It took about 2 years from start to production. It started out as a 3D driving game (like our new game Hard Drivin') where you drove down the road, stopped at shops alongside the road, and went in. Sometimes in the shops there'd be a video game which you could play. But this whole concept required too much time and storage, so we redesigned it as I, Robot. Doodle City was added to entice video game haters (girlfriends) to put in their money but I doubt that many ever even knew of its existence, and I've never seen anybody who got good at all the powerful 3D functions offered on the Doodle City menu screen.

Written in 6809 assembly code, using structured macros (begin/endloop, if/then/else/endif, for/endfor, etc).

I don't remember how much memory it took for the program and for working RAM. It seems to me it was around 48K for the program, about 1K for working RAM, ??K for the display list buffers, and ??K for the graphics files.

The math box did the matrix calculations. The 6809 did all the other math. The 6809 would decide the objects to be contained in each scene, or frame, then build a sorted list of the objects to pass to the math box. It would also set up the viewpoint parameters and other miscellaneous parameters. It would then call the math box, which would build a lower level display list of points, vectors and polygons. When it was done, it would tell the 6809 so. The 6809 would then see if the video processor was ready for action. When it was ready, it would tell it to get to work on the new display list. Everything was double buffered, so none of the processors spent much time sitting around idle. The 6809 had quite a job directing traffic, trying to keep everybody fully occupied, and handling frame overruns. The frame rate was flexible, but was usually around 18 frames per second.

Owen Rubin

An old email from 1997 I recently found where Owen Rubin talks a bit about I, Robot. Excerpts recorded here for posterity.

> > It started, if I recall, as a driving game in 3-D, but didn't work well.


> Wow, interesting!

Was actually quite interesting. There was a car and a hilly terrain made out of the polygons. There were some problems making the car 'clip' over the hills, and of course, if your driving that car, you want to be able to see it at all times. Then of course, what game do you play? The hardware could NEVER do something like SF Rush or the like, so it would have to be simple. On the other hand, it was REAL 3D, not the quasi-3D done in today's driving games. This was real polygons being translated and projected in real time. Was quite cool.

> 1) IR prototypes/test versions

I do not recall, I do not think it ever went out as anything other than IR. However, the doodle mode was added late in the development, so games without that are prototypes. Also, it was moved into the Major Havoc cabinet late (because Mark C and I did not meet our release deadline on MH, and IR needed a cabinet, and there it was sitting in the lab we shared! *SIGH*

> 2) vector prototypes/test versions (since Owen worked on MH)

IR was never done as a vector game, at least as far as I recall. Dave S was working on the hardware, which we all called Mondo Condo because the RAM chips on the development board were stacked upwards about 10 high and wired that way. The prototype boards looked like they had little apartment or condo buildings on them. Somewhere back in development, the game board was so large, they started calling all his designs 'Mondo". Then, the ram stacks added the "Condo". Designs after IR were called Super Mondo Condo and the like!

> Another Dave Sherman "crazy, mondo" hardware design.

It took a long time.

Rusty Dawe

The following are excerpts from an interview with Russel 'Rusty' Dawe over at coinopspace.

Coinopspace: How hard was it to bring I, Robot to market what with all its hardware complexity and the technological “1sts” it brought to the table?

Breighton (Rusty) Dawe: Atari held 3 patents on that technology. It had the first large-scale custom ICs, it had two “quad-pokeys” — a new way of getting more sound effects in, challenging! Not only that, the market was going through one of its cycles which is always a tough time for innovation.

Coinopspace: Rusty, can you dispel the myth of 500 I,Robot(s) being dumped into the Pacific Ocean?

Breighton (Rusty) Dawe: Not true. Total myth. I would have LIKED to dump about 500 I Robot controls into the Pacific – they were a nightmare, but that didn’t happen either. We were using the Hall Effect.

We had an arcade in Seattle we were testing and it was playing itself sometimes! Turned out the arcade was next to a scrap yard with a monster crane magnet – was playing the game from 100 yards away! Turned out the control needed to be separately grounded (and shielded) to the PC board. All the production controls that used the hall-effect did that after that test.

Not sure which arcade, but we kept exchanging controls with them for months and never found the problem until they explained where they were located. Finally, the mechanical group just grounded the SH*T out of it and it started to work.

Dave Sherman

The following are excerpts from an interview given on The Ted Dabney Experience. The original podcast is here.

TDE: And of course after Missile Command you went on to work with Dave [Theurer], clearly a successful partnership that you're happy to revisit on the incredible I, Robot.

Dave Sherman: Yeah. I was proud of that.

TDE: Yeah, and so you should be. Dave you're you're credited with creating, and bear with me here, the "custom bit-slice pepperoni 3D co-processor" whatever that might be, as I mean clearly the game was a was a technical masterpiece for its time. I just wonder if you can tell us briefly about the project and your involvement and were you more than just an engineer?

Dave Sherman: Oh yeah... for Battlezone there had been like a pretty simple stripped down mathbox that did... like what they would do is they would feed it 3D points, and the mathbox would munch on it and spit them back, and then the the programmer was responsible for... you know.. drawing the vectors, right?

TDE: Yes.

Dave Sherman: So that would not work at all in a raster game... like a full 3D with bitmap filling and so on. So what I did is I created... actually it was a full on computer basically... It had all of the all of the logic and arithmetic commands you would want... you would feed it a a display list. It was like a first... it was almost like a professional CAD level of hardware... The programmer Dave would feed it the database where we had a whole terrain generator that would... it was a special database... so he'd say "this square of the database is a particular type, and it's this high..." and so on so forth. And he'd feed that whole description in one chunk to...  I actually I called it Mondo Bondo, not pepperoni, internally myself. I may have made a joke to somebody at some point about pepperoni... but all the documentation internally was Mondo Bondo... And so he would feed that... and then it would chunk away running a full program,  which I wrote on this special hardware, that would parse the database, transform everything in 3-space to be in the correct spot on the screen, project it, illuminate it, cull out all the invisible polygons that were faced away, and it was it was a full on Harvard architecture mini-computer actually in in the game actually. So I was very very proud of that, and I did it cheaply.

TDE: Yes, but what I was going to ask you if there were any particular tricks, because I would imagine at face value I, Robot couldn't have been a cheap game to produce. So I would imagine there was some pressure on you...

Dave Sherman: There was.

TDE: ..either assumed or direct, to cut some corners.

Dave Sherman: I made it as cheap as I could and still do a full true-3D game as we would know it today with the transformations. The 2901 bit slices were an AMD part, and they had a controller part, the 2910, which was very expensive and it was actually clunky, I was shocked as an engineer. It didn't take full advantage of the 2901's. So I ditched that and I did my own controller. I looked at the the spec for how each instruction that the 2901's would execute had a different speed, and they told you what the speed was, and I looked ahead and each instruction got its own execution speed, I would adjust the clock to get the maximum speed out of each instruction, but not tie a simple instruction to the same speed as a more complex instruction, and they didn't even do that themselves! I was shocked. So that's one thing I did... A funny story is about cheapness... I originally targeted that the microcode would be 256 words deep, and I designed the whole thing that way. Well it wouldn't fit, and we added more and more features, and at that time you did prototypes as a wire wrap. It was like individually you'd have this big pegboard and a tech... like an assembler, would... you tell them how to wire it, and they'd wire it. And and so it was very expensive to redo. So we didn't. So what I did is I soldered RAMs on top of of the RAMs... Like I said, it got four deep... It got up to like 1,000 words.. And so the joke was... I was embarrassed by it, so I would cover it up with a little cardboard thing.. because the joke was it was the Mondo Condo, and... okay and this is too much a techy detail, but that during one of the reviews they they embarrassed me by pulling off the little cardboard thing, and people could see that it was this weird stack of memories you know.. but the reason I went down that path initially is because I was worried about the cost.

TDE: Right.

Dave Sherman: I was worried that they wouldn't approve it, because of the cost of the memory. So I tried to be cheap on the memory, and so that's that's an example also of how you got in trouble with being too cheap.

TDE: Right.

Dave Sherman: So I resisted actually. For this particular project I was in love with the idea of it being the first color full 3D... and I resisted them. I said "okay, well look.. if you want to do this it's just gonna cost $450 bucks or whatever. It's not gonna cost $190 or $200 bucks, because that's just the way it is."  But yeah, I got side eyed quite a bit.

TDE: I mean it's certainly one of those games which is loved and revered by collectors today because of its technical achievements, and obviously it's rarity. And it's pretty clear, listening to you, Dave, that would it be true to say it probably represents your best work at Atari from an engineering standpoint?

Dave Sherman: Yeah. I would say that's absolutely true. I took full ownership of the hardware. I wrote all of the microcode program which did almost all of the display grunt work and the positioning. I mean Dave was great with the gameplay, and how the characters moved, and you know coming up with ideas we came up with. We would play off each other in terms of "Well, what about adding sharks, flying sharks?" Or "What about what about weird birds flying over?" You know and stuff like that. But yeah I would say I'm most proud of I, Robot.

TDE: Yeah, but I mean looking back there's probably more than one reason... But do you have any thoughts on why it wasn't the same sort of commercial success that something like Missile Command was?

Dave Sherman: Well, it was the first, you know? And actually... it ended up as I, Robot after a lot of false starts in terms of what the gameplay was going to be... We had a game where we would roll big balls over the landscape, and we had like a full on-terrain, you would roll balls and then try and avoid things like one of those mechanical maze games, where you roll a ball through. So we had that.. and we had actually had a flying game called Ice World which was going to be a rip-off of Star Wars. But I think in the end you know... it's like people had trouble just *getting it*. They were used to a certain style of game. And there were some pasty growth games, but they were on a rail, pretty much on a road... So I think that was one reason people... And also I mean it's genuinely a weird game... I mean you know some robot and a big eye... And we were we were influenced by 1984, and the I, Robot series of Asimov books and stuff... But I think it was just not what people were used to. And then I guess the for me the the main thing was that it was released into the maelstrom of Atari dying horribly in 83-84. So the idea of polishing it yet some more was rejected, and it was like "ship it".

TDE: Yeah. I think it was probably just ahead of its time for all sorts of reasons.

Dave Sherman: It was.

TDE: And ultimately it sold poorly, and it was more prone to failure than other games. Would that be fair to say, Dave?

Dave Sherman: For a couple of reasons. Yeah... that's fair... for two two big reasons. One was the Hall Effect joysticks were very delicate, and so you know those would would cause trouble. And a lot of trouble... Dave did a great job of tuning the you know the signals that we got from it and we worked very hard to to make it work, and I did a lot of electrical engineering trying to get it to to be stable. So we did eventually. But still it was always just a little funny... And the other thing was that we we had a custom design group that that would do custom chips. And we were we were worried about people just ripping off the hardware. So the idea was "let's put some of this circuitry in a custom chip called the ICY chip", and I architected the ICY chip, and ripped out a bunch of MSI logic from the PC board, and they did an ICY chip. But it was tweaky too. And I spent a lot of time dialing that in as best I could. So those those are the two that stick to me. Yeah. Anyway. That was a problem.

TDE: Interesting. there is a urban legend about I, Robot of course, Dave, which you may want to be familiar with... and so legend has it Atari shipped 500 unsold I, Robot units to Japan with instructions to dump the units into the ocean at the halfway point.

Dave Sherman: I've heard variations of that for a couple of... No I mean I've heard that, but that one I don't believe... but I know that there were other games... actually there were cartridge games that I've heard were dumped into the desert and buried, or dumped overboard. I don't really believe that one, I think... I mean they made 750 [I, Robot machines].. and then that was it, you know? And then.. you know.. there was a disappointment.

TDE: Although Howard Scott Warshaw said for years that he didn't believe ET cartridges were dumped in the Amarillo desert, and it turned out they were.. so you know...

Dave Sherman: Exactly... you know... so I can't say for sure... I mean Atari at the end, under Ray Kassar, was incredibly corrupt... not on the engineering side but on the business side... It was like... so I don't know exactly..  it's believable they could have... they would have thought about doing that, yeah... but...

TDE: It does seem a bit over the top when you could have just had a massive bonfire in the parking lot I suppose, but...

Dave Sherman: Yeah, or you know, give everyone a sledgehammer...

TDE: Right. Yeah... Exactly.