Big Trak
item #4955 by Milton Bradley

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Call it coincidence (which I do not believe in), karma, kismet or whatever you prefer, but this is not the first time it has happened to me. I'm searching the web one night for information on a new robot I'd acquired and I came across a photo and a little information on something called a Big Trak. It looked a little familiar. Maybe I had seen an ad or a commercial for one when I was kid. I didn't think too much of it at the time - that wasn't the robot I was looking for right then. Then, two days later, I'm making my weekly rounds at the local thrift store and I see this thing peeking out from under a pom-pom! It was in fantastic shape for a toy that is going on 30 years old. Even the plastic axles, which from what I have read on the net are supposed to be the weakest link on the otherwise indestructible Big Trak, were intact. All I can say is that fate must have brought us together...

The wheels wouldn't spin when I first powered it up and the microprocessor got stuck in a loop whenever the motors where supposed to turn. Armed with the fantastic technical information on David Cook's website RobotRoom.com I was able to successfully disassemble the body and verify that everything was electronically sound on the mainboard. I did resolder a couple of suspicious solder joints - but that wasn't the problem. After putting everything back together, it still did the same thing. I had already tried spinning the wheels to make sure they weren't jammed, but just for the heck of it, I tried spinning them right when the program told the motor to turn. For some reason, which I still can't figure out, that worked! From then on, the wheels have turned every time on their own. Go figure...

This is a cool toy. You program into it, via an on-board membrane keypad, the actions and directions that it should follow - up to 16 steps can be programmed at one time. It will then follow those directions exactly each time you press "Go" on the keypad. You can go forward or backward in any number of "lengths" (each step is one length of the Big Track - approximately 13") from 1 to 99, spin left or right in any number of degrees (numbered 1 to 60 like seconds on a clock), fire a "photon cannon" (an incandescent light bulb under a blue plastic lens) and even dump a load from an optional Transport unit. There is also a button labeled "In" that the manual says is to be used on a future to-be-released accessory. This unknown accessory was never released. You can read more about that in detail on David Cook's site.

Year Released: 1979
Original Price: $43

Technical Specifications:
CPU: proprietary programmed 4-bit TMS1000 @ 0.2 MHz
Memory: 1024 byte ROM / 64 bytes of 4-bit RAM

Power Supply: 4 x D batteries and 1 9-volt battery

Dimensions: 5½" heigh x 8½" wide x 13½" long
Weight: 3 lbs

Click Here To Download the Big Trak Owner's Manual
Click Here to Download the Transport Owner's Manual

If you happen to need a set of replacement decals for your Big Trak, I'm sure you've found that they are no longer professionally produced. Fortunately, dlw6290 was kind enough to give me permission to host the images he created from the originals. Just download the images, decompress the file and print them out on clear decal paper using your inkjet printer - making sure to mirror "Big Trak 1.psd" for use on the opposite side of your Big Trak.