Solving a Logic Circuit Puzzle: Minimizing to SOP Form

[MagLok]

Homework Statement

Here is an image of the problem (Write the circuit in min SOP form.) http://img211.imageshack.us/my.php?image=ddtl0.jpg

Homework Equations

The Attempt at a Solution

I've looked at it and gone over notes but I don't get it. If you would like I can scan my sheet of scribblings on there but they're all uneducated attempts to solve this.

 

[MagLok]

Ok, I went through it and I think that it's one big NAND. so the min sop is NAND(A&B&C)

Any confirmation?

 

[berkeman]

So what's your equation for the output in terms of A, B, C? Show us your K-map.

 

[MagLok]

http://img175.imageshack.us/img175/9707/test2009or8.jpg

Here's a scanned copy of the latest. Not feeling too good about number 1 since I'm getting all zeros on my truth table for number 2.

 

[berkeman]

http://img175.imageshack.us/img175/9707/test2009or8.jpg

Here's a scanned copy of the latest. Not feeling too good about number 1 since I'm getting all zeros on my truth table for number 2.

I think I see an error in ABC~ in the first equations... And you need a pull-down on the first circuit to make it meaningful. Please re-check the tables to see if I'm making an error...

 

[MagLok]

Ok, so I re-did this problem and got ~C as the final answer. I'm pretty confident that that's the right answer, but please confirm

EDIT:

Ok, re-did it again and got (A&~B) | (~A&B) | (B&~C) | (~B&~C)

More confident this time around