The ability to code in x86 assembly, which might have been a useful skill 30 years ago.
ProgStart:
   MOV AX, 0B800H
   MOV DS, AX
   MOV BX, 0

ProgLoop:
   MOV WORD PTR DS:[BX], 0C6CH
   ADD BX, 2
   MOV WORD PTR DS:[BX], 0E6FH
   ADD BX, 2
   MOV WORD PTR DS:[BX], 0A6CH
   ADD BX, 2
   MOV WORD PTR DS:[BX], 0720H
   ADD BX, 2
   CMP BX, 4000
   JL ProgLoop

ProgEnd:
   MOV AX, 4C00H
   INT 21H
   END ProgStart

As it's a less than transparent language, I have provided a screen shot of what this does.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Mon 4 Jul 2011, 12:14, 3 replies)

I think i'm turning japanese

( The Mock Turtle ™ --- Thinks you are a cunt, on, Mon 4 Jul 2011, 12:22, closed)

You really think so?

(sabre-tooth monkey, Mon 4 Jul 2011, 12:30, closed)

Lacist
( The Mock Turtle ™ --- Thinks you are a cunt, on, Mon 4 Jul 2011, 12:40, closed)

I like to MOV AX MOV AX

( Undulating Tentacles of Love getting fun down to acceptable levels, Mon 4 Jul 2011, 12:28, closed)

All programmers all over the world!
I love the way all programmers MOV WORD PTR DS:[BX]! And when you MOV WORD PTR DS:[BX], want you to MOV WORD PTR DS:[BX] nice and sweet and sexy - a'aight?!
(sabre-tooth monkey, Mon 4 Jul 2011, 12:31, closed)

:D

( Dr. Shambolic je suis charlie, Mon 4 Jul 2011, 12:53, closed)

I like this!

( The Mock TurtIe ™ --- Thinks you are a cunt, on, Mon 4 Jul 2011, 23:38, closed)