It's never too late, in my not so bloody humble opinion.
If the kid liked playing with Lego, Mechano, (K-Nex these days?), making wooden stuff or even sand and snow - when younger, then there's a good chance that the spark is there. There are scads of other possible indicators that the talent might be there, too.
I think one needs a bit of logic - but not as much as people pretend - to be a decent coder. A lot more different talents to be a great geek, but there are stacks of different sorts of geek, so even which skills one is best at is just character.
What makes a person have potential as a geek - and I think there is just one thing:
You have to like to fuck with shit .
Games got me into coding - I liked to play them, and I wanted to make them. Turns out, I enjoyed coding as much as playing games. I discovered I loved debugging, optimizing, and just writing regular code.
Some kids these days are just getting into coding. Go check out the forums - it's bizarre, they chat like lolcats on meth, but some of them ask real questions and are seriously banging their heads on shit. Answer their questions. I see kids trying to make USB video game controllers using common microcontrollers (AVRs and PICs) to bit-bang the low speed interface - they want to know why their out-of-spec stuff works on the right USB port, but not the left on their laptops (yup - Apple). ;] They need help with problems. Sometimes daft, and sometimes not. Sometimes you remember the class of bug that they are hitting and how long it took you to crack it the first time...
Maybe if we knew what sort of gamer the subject was we might make a claim as to what sort of coding they might enjoy. Ultimately, the way to find out if someone likes to code - is to try out coding with them.
Personally, I love pairing, so taking a newb for a ride can be a lot of fun - they can get to see a program develop a lot faster than if they had to crack every problem themselves, but if they are still typing in the whole deal, it will feel much more like you showed them how, but that they actually did it.
And - you know what? A friend of the family was a coder - he noticed that I liked video games and showed me how one can write them. First via typing things in from Compute! (and perhaps BYTE, is blurry memory)... then via coding in basic - ultimately someone gave me some books on C, and I got a compiler off of a friend in class ('this thing is five disks, and it's not even a game - yer nuts!')... thing came with a shell, micro-emacs (shudder), and a debugger. Debugger meant I could see what my code compiled into, and thus I fell into the hypnotizing pool that is assembly on the 68K...
I call BS on there not being fresh kids getting into it. Look at robotics, the maker scene, Ubuntu, the modding and addon gaming scenes - find folks who have questions that you know how to answer - and bloody well help them.
PS: The era of 8-bit pixels was the 90s - for consumer-level hardware, if you recall. The 80s were all that irritating bit-planes, monochrome, four, 16 - even 12 colour modes. Don' even think of telling me to get off yer lawn. ;]