I did something similar, was looking to make a cable for my TiVo to connect serial to DB25 on the back of my router box so I could dial out over ppp instead of phone (was getting rid of home phone service).
I knew what I needed, a DB25 male kit and a 1/4" stereo jack. I went o Radio Shack and was looking at the parts on the wall when the kid came up and asked if I needed help.
"Yes, I need a DB25 connector kit and a 1/4" stereo jack"
I took a deep breath. I wasn't really looking for help on my part selection, just trying to find what should have been $5 in parts on a hook on the wall, really.
But I couldn't help myself.
"I'm making a cable for my TiVo"
"Why? TiVo should have come with all the cables"
"Yes, but I am building a serial cable to connect from the TiVo to a PC"
"To dial up over PPP"
"so, I just need these parts to make a cable, do you have them?"
"Well, the cables are over on this wall..."
felt like I was talking to the Secretary of the Interior
"but, Brawndo has what plants crave"
Disc space -- the final frontier!