Early 2600 (6 switch) console hardware question

[tvcasualty]

I'm new to these forums, not sure if this has been covered before...

I have an early Sears Tele-Games 6 switch 2600 console, the USA built type with the heavy shield. I had heard ages ago that these machines were designed to have an onboard game IC, and they do indeed have an empty spot on the board for the ROM, and if you drop a Combat game chip in, it does run when powered up. With the IC installed the cartridge slot doesn't work however (the onboard IC and the cartridge appear simultaneously at this point I presume). Has anyone reverse engineered their console to run both? I was thinking that maybe a microswitch that cut power to the game IC on the pcb when cart was installed might do it but haven't tried it yet.

tvc

[Pantechnicon]

You're right. The original version of the VCS was designed in mind with having Combat built-in.

Just an interesting (to me, anyway) observation about what might have been going on back in the Atari heyday: If you look at an original Combat manual you might notice that there are no instructions in that manual regarding the proper instertion or removal of the cartridge. Yes this info is covered in the system manual itself but not in the game manual itself, which just goes back to the whole built-in game thing. I think Air-Sea Battle (CX-02) may have been written the same way, which suggests that maybe it was also a contender for the rom slot. The manual included with the sold-alone boxed version of Combat has a cart insertion section, as well as all subsequent manuals produced by Atari as well as most 3rd parties.

[Jibbajaba]

I never realized the original Air-Sea Battle manual was like that also (very cool).

Ok, ready for this one? Guess which other Atari-made game was programmed for stereo ;)

Now, considering that there were 2 different versions of the console when it debuted (one Atari and the other Tele-Games), and that they both had different pack-in games (you'll never guess what TG's was LOL ) I think we can make a pretty good guess as to what Atari's original plans were for the system.

I will guess "Video Olympics".

Chris

[tvcasualty]

... Actually, I'm surprised nobody designed a circuit for it by now.

I've had a vision of a little "daughter board" with a couple dozen of my favorite games as a DIP controlled built in multigame. It will be the perfect spot for some homebrews or protos.

tvc

[tvcasualty]

I'll post any progress here. Currently I'm stuck looking for a suitable switch, so it may be a few days. I'm going to try switching chip select (I think it is pin 18 on the socket) high or low depending on cartridge insertion tripping the switch. If I'm lucky the onboard IC will be "off" when chip select is disabled.