The wizards at Williams Electronics turned out some of the most memorable games of the Golden Age, and ROBOTRON is definitely one of them.  Few games have ever matched it for sheer, frenzied action, and it – along with most of the Williams titles – remains a favorite and highly sought-after item by many game collectors.  Even in less-than-ideal condition, a working ROBOTRON can easily fetch several hundred dollars at auction – which is odd, considering how many of them were made; you would think there'd be enough to go around.  Then again, I'm sure a lot of these machines have been scrapped or converted over the years...

This was the fifth game added to my collection, in mid-1999.  I rescued it, along with my SPACE DUEL, from an auto-salvage yard in Bertram, TX., of all places!  One of my co-workers, who's passion is classic automobiles, had been by that particular salvage yard the previous weekend, had seen the games sitting there, and let me know about them the following Monday.  When I called to inquire about buying them, the woman who answered the phone said "It's a good thing you called, we were about to scrap them", and told me I could have the pair for $20.  For that price, I figured they either had to be gutted shells with nothing left in them, or so badly torn up as to be not worth fixing, and made the half-hour trip up from Austin expecting to be disappointed.  Imagine my surprise at discovering both were intact, both inside and out, and that they even had the original manuals still inside!  Of course, somehow the price had mysteriously inflated to $20 per game, rather than $20 for the pair...  which was still a hell of a bargain, but I haggled her down to $30 for the pair anyway just on general principles.

Of course, neither game was operational, which is almost certainly why they sat around inside the building for who-knows-how-long waiting to be scrapped... and I'm almost embarrassed to say how easy it was to get ROBOTRON back up and running; all it required was a new bridge-rectifier and a couple of new fuses on the power-supply board.  Yes, that means I got myself a fully-operational ROBOTRON for the princely sum of about $25.  You may turn green with envy now.

Of course, the cabinet was pretty dirty after sitting around in that kind of environment...  at first, the picture was so dim and unfocused I thought perhaps the monitor was going – and then I realized that, no, the poor image was because I was seeing it through a haze of oily dirt that had accumulated on the monitor and bezel!  I quickly disconnected everything and let the monitor discharge, then disassembled the front and gave everything a good cleaning.  Other than that, though, the game was in fantastically good shape overall, especially considering the kind of storage conditions it'd endured – the side art is a bit scuffed on one side, but not obliterated, and the control panel only has a couple of minor cigarette burns along the edge.  Heck, I didn't even have to replace the marquee light!

Unfortunately, a few years later, money got a bit tight in 2005 due to a spell of under-employment when Total Amusement, the arcade-services company I (briefly) worked for, went under and I had to make do with temp jobs for a few months, and a couple of unexpected expenses forced me to sell ROBOTRON to cover the bills.  I got $500 for it – which was, at least, a tidy little profit, considering that all told, I only had about $40 into it.

Wave 1 is fairly easy, with only about a dozen or so of the GRUNT Robotrons to contend with.  GRUNTS always move towards you, following you around and trying to box you in.  This can be both a good and a bad thing; on the one hand, it means they tend to line up in nice, easy-to-shoot clusters, but on the other hand, if you get surrounded by a bunch of them, it's very hard to escape.  As long as you can keep your distance from them, though, you're relatively safe – they can't shoot at you; all they can do is try to run into you.  Oh, and be sure to stay away from the ELECTRODES.  There aren't many of them in this stage, but they can be a nuisance; it's surprisingly easy to forget about them sometimes.

HULK Robotrons make their appearance in Wave 2, as does a single SPHEROID which will begin spitting out ENFORCER Robotrons once it reaches one of the four corners.  HULK Robotrons are indestructable; your lasers will slow their motion, but won't kill them.  They will generally ignore you, and head towards the nearest Human Family member to destroy them; they're only dangerous to you if you happen to be in between them and a Human Family member.

Wave 3 is where the SPHEROID and ENFORCER Robotrons start getting seriously into the fray; three or four SPEROIDS will zip across the screen to the far corners, and each will generate up to five ENFORCER Robotrons if not destroyed before they reach their destination.  ENFORCERS also move towards your position, as the GRUNTS do, but they're faster and, unlike GRUNTS, can also shoot back at you.  Your one advantage here is that due to a bug in the ROBOTRON software, the closer an ENFORCER is to you, the slower he and his shots will move.  (Yes, it is a bug – but the programmers deliberately left it, in because they thought it was more interesting that way.)

Wave 5 pits you against the BRAIN Robotrons.  BRAINS immediately head for the nearest Human Family member (of which there are a lot on this screen) and, if they catch one, reprogram the unlucky human into a PROG.  Like GRUNTs, PROGs can't shoot at you; all they can do is race somewhat aimlessly around the screen trying to run into you.  Nonetheless, they can be dangerous since their erratic paths are difficult to predict.  BRAINS can also fire Cruise Missles at you, which will hunt you down – or try to, anyway; Cruise Missles don't seem track very well, and usually seem to just kind of snake around the screen while heading in more-or-less your general direction.  And, of course, you have the ever-present GRUNTs to contend with.  This wave also has a larger-than-usual number of ELECTRODES scattered around the field, just to further complicate things for you.

Note that a bug in the BRAINS behavior causes them to preferentially seek out the Mikey human over the Mommy humans, so you can potentially rack up a huge number of points if you try to keep the BRAINS from getting to Mikey (without picking him up yourself) while you rescue as many Mommies as possible.

Wave 7 begins with about a dozen QUARKs pulsing their way around the screen.  After about ten seconds or so, they'll begin turning out TANK Robotrons.  TANKS are particularly nasty enemies to deal with; not only do they shoot at you, but their cannonballs will bounce off of the edges of the screen.  These, too, suffer from the same software bug as the ENFORCERS; they closer they get to you, the slower they and their cannonballs move.  (Unfortunately, cannonballs already fired do not slow down as they approach you!)  There are no GRUNTS in this wave, but there are quite a lot of HULKS and Human Family members wandering around this stage.  Don't be tempted into trying to rack up points rescuing the Human Family from the HULKS at this stage, though; you'll have quite enough trouble on your hands just coping with the TANKS!

Try to avoid shooting the TANKS' shots as long as you can – if the TANKS fire 20 shots that don't hit anything, they'll cease firing at all, and that will make them considerably easier to pick off (and might give you some breathing room to rescue some Human Family members for extra points).

Wave 9 hurls a ton of GRUNTs at you.  There are no ELECTRODES, SPHEROIDS, or other enemies (except a few HULKs tracking down a handful of Human Family members), but you'll be too busy dodging GRUNTS to enjoy their absence for long.

Beyond this point, the cycle repeats, with the enemies getting more numerous and aggressive.  I've heard rumors that something special and/or bizarre occurs if you can roll the wave counter over from 99 to 0... but I can't verify that, since I've never been able to survive anywhere near that long.

The ROBOTRON logic boards.  The largest board on the left is the CPU/Video board; the upper-right board is the ROM board, and the small board on the lower-right is the interface to the buttons and joysticks.  The ROM board, by the way, features two large 40-pin custom chips which appear to be microcontrollers and/or bus-interface logic of some kind.  At least, that's my guess from the schematics.

ROBOTRON uses a 6809 microprocessor for the game itself, and a 6808 for the sound board.  Unlike many other games, the sound is generated directly by the 6808 CPU, through an 8-bit DAC, rather than through one of the commercially-available sound chips like the AY-3-8910 or the SN76477.  This is, in large part, responsible for the unique sound of Williams' games.  ROBOTRON also uses its own video-generator circuitry, rather than a stock graphics controller.

On the left is the Sound Board, and on the right is the power supply – the source of this particular ROBOTRON's troubles when I acquired it.  One of the diodes in the bridge rectifier had shorted, which was blowing fuses as soon as the game was turned on.  The one I replaced it with is rated for higher voltage and current than the original, so that problem shouldn't repeat itself.

The power supply in this thing, I've since discovered, is very sensitive to power-line glitches. For a while, I had a spontaneous-reset problem – which, of course, only occured when I had people over playing the games! – which I feared would require some heavy-duty diagnostic work on the CPU board... turns out that it was just noisy power caused by having too many games running off of one power strip at once.

The monitor is a 13" color raster in the cocktail and cabaret models, and a 19" in the upright model.  Both monitors were made by Wells-Gardner, a company which was (and still is) a major player in the gaming-monitor market.