FB2 Cartridge Auto-detecting/Auto-switching Circuit

[Prodos8]

Anyone installed one of these in place of the mechanical DPDT switch to select the cartridge/internal rom?

 

I read over the instructions for one on Lab Rat's site (link: http://www94.pair.com/jsoper/flashback2.html) which looks interesting. However, I don't have one of those 4016 bi-lateral switch ICs at the moment, but I do have plenty of loose transistors. So I came up with the following circuit using a pair of transistors to switch the jumpers back and forth when a cart is inserted/removed.

I'm a complete novice when it comes to electronics -- I haven't yet installed it so I was wondering if anyone had advice on whether my circuit will work or not?

 

Thanks.

[jsoper]

You know, I did my 4016 circuit because Kevin Horton reported that for Bankzilla, he was never able to find a cart that didn't short the two ground pins together. And Kevin is never wrong, you younguns may not know the name, but he did some incredible stuff in the late 90s before anyone else.

 

So I got that project done, and guess what? Found carts where the grounds weren't connected together, especially on Activisions. So I'd say use a level switch.

[Prodos8]

You know, I did my 4016 circuit because Kevin Horton reported that for Bankzilla, he was never able to find a cart that didn't short the two ground pins together. And Kevin is never wrong, you younguns may not know the name, but he did some incredible stuff in the late 90s before anyone else.

 

So I got that project done, and guess what? Found carts where the grounds weren't connected together, especially on Activisions. So I'd say use a level switch.

Crap!

 

I sorta took your research as gospel. Shame on me I guess. I'll just install a mechanical switch so I can play all the compatible carts with the FB2. I just have it hardwired to play carts (not roms) at this moment.

 

Thanks for your response, I really appreciate it.

[Retro Rogue]

You know, I did my 4016 circuit because Kevin Horton reported that for Bankzilla, he was never able to find a cart that didn't short the two ground pins together. And Kevin is never wrong, you younguns may not know the name, but he did some incredible stuff in the late 90s before anyone else.

 

 

Yes, Kevin was doing hardware hacking long before Ben Heckendorn, and actually has a background in electronics. For his 5200 jr. he laid out a completely new main pcb.