Nuts 'n Bolts
Luckily the schematics for Computer Space have been saved as an Adobe PDF file. I originally found this file on the Killer List of Videogames and have included it here.
I personally have glanced over these schematics, knowing a thing or two about electronics, but I am certainly not capable of troubleshooting the machine. I do know of a pinball shop that services old machines and the technicians there have worked on Computer Space before. If you need any troubleshooting help, check out their website http://www.flippers.com.
Click on each thumbnail below to see a detailed measurement of each side of a Computer Space cabinet.
A couple of items to note:
Firstly the width and height of the TV screen are as close as I can measure by eye as I hold my measuring tape against the plexiglass panel. I have not actually opened the unit up to measure the TV precisely. It certainly looks like it measures 11" by 9" which, according to Pythagoras, means the corner to corner measurement is 14.2" and it certainly looks like that if I hold the measuring tape that way. However, the general consensus on the web is that Computer Space held a 15" TV (some sites erroneously state 13"). I would say that is still correct as, in the television set business, vendors usually described the TV size by the complete corner to corner measurement of the picture tube, despite the fact that an inch or so may be taken up by the housing. So, I stick to my measurements of the TV on my unit.
Secondly, I made a grave error when I first looked at buying this unit in assuming the base is completely square. So when I measured a 28" base along the front, I assumed I would have no trouble getting it through the 29 3/4" door to my apartment. Having paid a very large sum for this beautiful machine, you can imagine my horror when I got it home and discovered the base is tapered and actually measures 30" along the back! With a lot of luck and some resourceful angling, we still got it through the door, but I warn anyone intending to buy one of these machines to bear this fact in mind!
So some general questions:
How much power does it draw?
About 200 Watts total, it's really the TV that sucks up the power and I have heard the machine in general takes about 1.5 to 2 Amps to run.
Does it get very hot?
Not really. I have left mine on for eight hours and felt very little heat coming off the control panel or the motherboard. However, in the space above the TV set there tends to be warm air sitting up there, nothing more than you would expect from any television set left in an enclosure for eight hours though.
How heavy is it?
Surprisingly light. One person could pretty much lift Computer Space, although it is bulky. I have actually done it myself but I wouldn't recommend trying to carry it far in case you trip. I weighed mine since I figured people would want to know shipping weight in the off chance they might buy one and want it delivered. Now, without a proper wide-bottom scale it was difficult to get an accurate reading. By propping regular bathroom scales under the front lip and then again at the back, I got a reading of roughly 95 to 100 pounds. Certainly, for the purpose of shipping, I would say Computer Space weighs 100 pounds.
A recent reader told me there's a list of custom fixes many collectors have made to their machines. Consult the following list of home-remedies:
Common fixes/stuff that goes bad:
Power supplies: Notorious for going bad. The game boards only need 5 Volts to run, and it means 5 Volts. If you have a wavy picture, most likely, you have a dirty or low power supply. A standard switching power supply out of a modern game is an easy swap and can sit where the original did (on the shelf in a 2 player or on the door in a single player). If the person working on the game cannot tell what piece the power supply is, they have no business changing it. Seriously, save a costly repair.....if you don't know what you are doing, don't do it!
These games often had no grounding, and therefore were nice static shock monsters. Many folks figured out early on that a static charge would cause the game to credit up for free. Often, these 7400 series IC's found a good bit of that shock, causing them now to fail. Honestly, they probably failed 30 years ago, but no one tried to play and figure it out! Check the schematics if you cannot coin your machine and see if the coin circuit is working properly. An inexpensive logic probe will prove your best friend on this one....
Tubes in the TV:
The GE black and white TV in your machine uses vacuum tubes. All are still readily available as New Old Stock (or NOS). Nolan Bushnell (in the manual) recommended changing the tubes every 3000 or so hours of normal game usage. Thats about a year of being on in a bar. I would think storage for 30 years counts (even if your game did not see very much use back in the day).
If you find your game has no volume, check the speaker first. They are 4 or 5 bucks at Radio Shack. The TV speaker was remounted onto a vent hole in the backdoor of the machine so you could hear it better. They were then exposed to the elements in storage. The game will never wow you with HIFI, but at least you will hear it better. DO NOT replace the speaker with anything other than what it had. No big car speakers, seriously. You will damage the TV
On buttons and levers:
If you have a broken spring contact, try a video game leaf spring. If you have buttons (like in the 2 player joysticks), you are on your own. I used some small circuit boards and populated them with momentary switches from Radio Shack. By no means was it the best fix, but at least it made it through some shows. The duty cycle (that's how many times you can push the button) was extemely short on the originals, most likely to save money. Other Nutting equipment used weird switches (Doorbells, I kid you not!), so it would not surprise me. Remember, these were not meant to last as long as they have.
Do's and Don'ts:
Do enjoy the beautiful cabinet. A coat of carnuba car wax (not the "with cleaner" kind) makes them beautiful
Don't store it in a damp location. If you know your basement leaks, get that thing out of there. Setting the machine up off of the floor on 2X4's laid left to right (one front and one back) is one way to keep it dry. The game has no feet, and if the wood swells, it will separate from the original fiberglass casing.
Do encourage people to come see it, play it touch it...
Don't let a bratty 5 year old with an ice cream cone come within a city block of it :). I had one hanging on the joysticks once. I'm a teacher, and even I was out of patience at that point.
Don't leave it plugged in. Unplug it when you are done.
Do replace the eletrical plug so it has all 3 wires working. The ground prong was usually clipped off because outlets did not commonly have all 3 plug wires back then.
One of the funniest Tech Tips I have received is regarding the rubber baffles surrounding the Two Player Computer Space joysticks. The following unit has baffles that fit perfectly.
Where is that unit from, you ask? Click here to find out.
On occasion, a Computer Space machine can be found with a different power supply than its original. The original powersupply (circled in red on the left) is a linear unit and as such it is very heavy and runs quite hot since all the current has to go through the power transistor.
The switching power supply shown on the right had the advantage of being lighter and running less hot. At first, this benefit was countered by the fact these types of power supplies were noisy electrically and used to be more expensive than traditional linear power supplies. However, as time went by and more modern games used switching power supplies, these faults were phased out. In short, a Computer Space still using its linear power supply is considered more of an "original" condition piece. Machines that have the switching power supply modification are merely more robust.
Noticable on some machines that grey circle is on the front of the machine, what is it?
It's a keyhole.
One can only assume that arcade owners who may have had Computer Space sitting side by side with other machines may have tired of having to pull the unit out to get into the back door to empty the coinbox. Perhaps this key unlocked the control panel at the front to allow easier access to the coinbox?