THE ART OF HUMAN COMPUTING

Finger-Coded Binary

TOBIAS ENGLER

When it comes to the development of Artificial Intelligence systems, scientists tend to conjecture that man himself, encompassing the brain with its bazillion synapses and neurons, is the paradigmatic super-computer. "Computer?" you might ask, "Where are thebits and bytes, the binaries that make it a true computer?"Hold on; disclosure is only a paragraph away.

On a recent camping trip, I observed a friend of mine making some strange gestures with his left hand. When I inquired about this, he asked me whether I could figure out how his raised middle finger represented a binary 4. After getting over my initial surprise at the gesture, I began to understand: it was finger-coded binary (FCB).

THE BASICS OF FCB The single- and triple-handed excepted, the averagely handed human being is capable of producing a number range of up to 2^10 by using his or her fingers. Every finger represents a bit of information:

Left hand, thumb (L1): Bit 0, value 1
Left hand, index (L2): Bit 1, value 2
. . .
Left hand, little (L5): Bit 4, value 16
Right hand, little (R1): Bit 5, value 32
. . .
Right hand, middle (R3): Bit 7, value 128
Right hand, index (R4): Bit 8, value 256 or carry flag
Right hand, thumb (R5): Bit 9, value 512 or overflow flag

Though I prefer this style (palms facing in), your personal style may vary.

To set a bit, you only have to raise the respective finger; to clear a bit, bend the finger. LSL and LSR do the same they did back in Apple II-land ("shift" your fingers left or right), as do ADD and SUB. (To add, look at each bit in the number you're adding, least significant bit first. If the bit is set, set that same bit in the number you're adding to. If a bit you're trying to set is already set, clear it and set the next higher bit instead.) That's all you need for basic mathematics.

Exercise:   (3 + 6)* 2
Solution:   Set L1, L2          --> 3
            Clear L2, set L3    --> + 2
            Clear L3, set L4    --> + 4
            "Shift" fingers right 1 position  --> * 2
Result:     L1 clear, L2 set, L3, L4 clear, L5 set      --> 18

CREATING REAL-WORLD APPLICATIONS
In general, nothing is prohibited. (If you're not sure whether showing the police your raised middle finger while shouting "I have to raise four children, you @#$%&!" is legally safe, consult your lawyer.)

In particular, here are some useful examples:

• Tell people your age. They'll envy you for being able to count your age on one hand (you may need two, but that's still amazing).
• Get a kick out of telling your friends your phone number. If you animate your fingers fast enough, you could even compete with QuickTime.
• Earn some extra money. Advertise yourself in any local or national newspaper as either (a) a human binary calculator, (b) a shadow puppeteer, or (c) a lunatic. Finger food obligatory.

I'll keep my bits . . . er . . . fingers crossed for you.

Oh, one last thing: If you want to expand your bit range, you might also use your toes (imagine a gigantic range of 2^20!) or even your ears (if you can wiggle them) or eyes (unless of course you're driving or are otherwise mobile). Good luck!

TOBIAS ENGLER is 19 years old, right-handed, and the "subcaretaker" at a church in Erlangen, Germany, where he's doing his community service (as an alternative to military service). When he's not taking care of anything, he's swimming or playing soccer or badminton, or he's on the road jamming with Rush, Dire Straits, or Bad Religion. *