Zonie, I would need to dig out the Coleco schematics to answer your question. However from my pass experiences using the system in the 80’s, and I also ran some extensive tests on the ColecoVision, Expansion Module #1, and Expansion Module #3 tonight that verified my memories were correct (Expansion Module #2 is just a steering wheel game controller and it has always puzzled me why Coleco named it Expansion module #2 when it does not even use the expansion slot). Then the address book dialer module that is pulse dialing only, was kind of a waste. Coleco could have instead included the feature in the released 300 baud modem if a extra phone jack was installed on the modem, or they could have released a 1200 baud or 2400 baud modem with built in auto dialer function. Why waste an expansion port for an auto dialer when a modem can do the same thing. The only advantage of the auto dialer was the hardware was at least half the price of a modem.
If one does not use the gray tray for Expansion module #3, and turns on both power supplies at once (the ColecoVision power supply connected to the ColecoVision) and (the ADAM power supply connected to the ADAM computer), the system still works since there is protection built in that does not fry the system with two power supplies at once (However I do not recommend doing this and I only left both power supplies on for 30 seconds or so. The system could become damaged if ran with two power supplies at once for a long period of time).
Anyways with the gray Expansion module #3 tray removed, and also the ADAM power supply completely removed. I plugged Expansion Module #3 the ADAM directly into the ColecoVision, then I also plugged Expansion module #1 ATARI 2600 adapter on the side of Expansion module #3. With the ColecoVision power supply plugged into the ColecoVision, I was able to use the ATARI 2600 adapter perfectly fine for picture and sound while it was plugged into Expansion module #3. However as soon as I removed Expansion module #1 from the side of Expansion module #3 the ADAM computer, I was able to see and hear the Smartwriter word processor, however the picture was a little distorted since it was like it was not getting enough power. However, my point is the ColecoVision power supply is powerful enough to allow one to see and hear Smartwriter, however the quality is poor and not useable. Even the ADAM printer power supply sometimes is not powerful enough to power everything hooked up to the ADAM computer. When the third party 2MB memory expander, two serial ports with parallel interface card, and hard drive card were all used at once, one also had to use a third party more powerful power supply for the ADAM computer so that everything worked properly.
Edited by HDTV1080P, Fri Oct 13, 2017 3:32 AM.