The famous founder of CollectorVision, Jean-François Dupuis (aka Retroillucid) has analyzed different materials to try to write the story of the prototypes developed by Coleco that led to the well known released hardware.
Here is the transcript of what he published on the AtariAge forum.
Console Prototype #0
Console Prototype #1
Console Prototype #2
Console Prototype #3
Console Prototype #4
Expansion Module 1 Prototype #1
Expansion Module 1 Prototype #2
Expansion Module 2 Prototype #1
Expansion Module 2 Prototype #2
Expansion Module 2 Prototype #3
Roller Controller Prototype #1
Roller Controller Prototype #2
Roller Controller Prototype #3
Roller Controller Prototype #4
Super Action Controller Concept
Super Action Controller Prototype #1
Super Action Controller Prototype #2
Super Action Controller Prototype #3
Console Prototype #0
This is the console that is believed to have been sold to Mattel which would later become the Intellivision.
It makes sense if you carefully look at the design and the cartridge slot placement.
Unfortunately, not much is known about this other than, when I've contacted the owner of this cell, he told me this was the console Coleco first made and sold to Mattel.
Console Prototype #1
This is the very first ColecoVision prototype and it has been rumored it was just rolling a tape inside of the console to show its potential during CES and other tradeshows events.
If you take a close look at the console, the console faceplate has a white ColecoVision logo with a rainbow strip in lines.
Note that the Coleco logo on the faceplate is red.
The cartridge itself looks almost like the final cartridge design but with an imprinted Coleco logo instead of an engraved one.
The cartridge slot is a perfect rectangle, instead of having a unique shape (like in the final design).
The joystick of the Controller is similar to the final one, but the numbers on the keypad have a very thick bold font. The Coleco logo is engraved between each side buttons.
The buttons seems different than the final design and their color is blue.
There's no Speed Controller (Roller Controller) in this design.
From an advertisement, it seems like Coleco already planned the Expansion Modules #1 and #2, but somehow, don't mention the VCS Module at all.
Donkey Kong cartridge was already listed as the Pack-in game with the console.
All of the "screenshots" used for the promo of this prototype were mockups.
Console Prototype #2
The 2nd Prototype is looking very similar to the first one at first look. Although, the cartridge slot area has been completely redesigned and moved to the front of the console.
I think the main problem with this design was the cartridge slot placement vs the Expansion Port placement.
The faceplate presents also some differences. The ColecoVision logo is, for some reasons, printed like Coleco never did, probably a print mistake. The rainbow stripe looks identical to the first prototype. The Coleco logo on this faceplate is now white.
This time, the controller of this 2nd prototype has a Coleco imprinted logo, instead of being engraved.
The Blue side buttons look identical to the 1st prototype controllers.
The Keypad also looks identical to the 1st prototype controller, but now the asterisk and dial buttons are yellow instead of black.
The Speed Roller has been added to the 2nd prototype controller, at the bottom of the keypad.
The Joystick area seems to have a kind of restricted movement shaped-hole.
"Screenshots" used during this era are still all mockups.
Console Prototype #3
This is probably the most obscure Colecovision prototype!
Not much is known about this one, and there is nearly no picture available but this one.
This is probably where things changed the most in the design.
The Cartridge placement has been switched back to its original position (see first prototype).
The faceplate is identical to the final design of the console.
The Controller has a few changes, it uses the very same bold font for the keypad, although the asterisk and dial have been changed back to black.
The position of the Speed Roller has changed. It is now under the engraved Coleco logo.
The side buttons are now grey instead of blue like in the previous designs.
The Cartridge slot is still a perfect rectangle...
Console Prototype #4 (Pre-Production Units)
This is the final design of the console, but not its controller!
The cartridge slot area has been completely redesigned, now with its final unique shape slot (instead of a perfect rectangle), probably in order to avoid people putting other system cartridges into the CV cartridge slot.
The faceplate is identical to the previous prototype which is also the final design.
The controller looks just like the final design but with the Speed Roller which would be removed from the final design, but is still visible on some PCBs.
The Keypad on the Controller now has a thinner font compared to the previous prototype.
This is the console that was in the famous Purple Box.
Expansion Module 1 Prototype #1
This prototype goes with the ColecoVision console Prototype #2
If you look at the ColecoVision logo on the faceplate, it matches the ColecoVision console Prototype #2
On this concept drawing, check the ColecoVision console Power and Reset switchs and the ColecoVision logo.
Expansion Module 1 Prototype #2
This prototype matches the ColecoVision console prototype #4.
It was also seen in an advertisement.
Finally, here is another concept drawing for the Expansion Module 1 which was probably made during the ColecoVision prototype console #4.
Is there a 3rd Expansion Module 1 prototype?
Expansion Module 2 Prototype #1
Here is the first (known) Expansion Module 2 Prototype.
Look at the controller position (on the left instead of the right side). The controller is also a prototype.
Comparison:
Expansion Module 2 Prototype #2
Here is another Expansion Module 2 prototype. This time there is a regular controller. The stickers on the module itself are different.
The controller is still on the left side....
Expansion Module 2 Prototype #3
Last prototype, with the correct (right) controller position. The set of stickers is different from the final unit.
