Auto switch between carts and built-in?

[pyl85]

Just about to start my second attempt at modding a fb2. I was wondering if anyone else had rigged up a way for the fb2 to automatically detect if there's a cartridge inserted and, if so, to switch to "cart mode." I followed the link to John Soper's page detailing how he did it with a quad analog switch. Looks good, but I don't have the required chip and Radio Shack doesn't appear to carry them. I'm going to try to use some of the 2N3904 transistors I have left over from the CD4050 A/V mod. No idea if it'll work, but, hey, that's half the fun

 

I just thought I'd ask if anyone else had modded their fb2 with auto-cart support and if so how.

 

Thanks,

Greg

[phil_vr]

Just making a good guess that it could work in a "petended way". I havent modded anything, I just fiddle with things.

If you use a switch (say from a broken computer joystick) in a way that once the cartridge is inserted and fully in, the

bottom cart part to press this switch, therefore enabling the cart option, and once there is no cart inserted to press the

switch then it would be running in the built in mode. it cant be that hard, but like I mentioned, I am just speculating.

I guess it can be pretty tight in the FB2 case, but I think it is possible.

[jbanes]

Member jsoper has a website with quite a few mods, including the circuitry for an autoswitching cartridge mod for the Flashback 2.

[jsoper]

After I did my mod, I came across a few carts where it wouldn't work because the cart

didn't short the two ground connections together. Activision Boxing was one if I recall.

It's funny because Kevin Horton stated all carts worked when he invented the trick for

Bankzilla and you don't catch Kevin being wrong very often.

 

Curt's original suggestion of leaf switches is probably better.