Here Come the Microkids

  • Share
  • Read Later

(7 of 10)

Indians—is PLATO (for Programmed Logic for Automatic Teaching Operations). Developed in the 1960s by the University of Illinois and Control Data Corp., PLATO is an exemplary teacher containing more than 8,000 hours of courseware, much of it in a continuous curriculum. Thus if a youngster forgets a point from an earlier lesson, PLATO will search its prodigious memory and patiently recapitulate.

But such time sharing schemes are extremely expensive, since they require open lines to the central computer. They also can become backed up at peak hours, and do not always lend themselves readily to what is the most intellectually demanding use of the computer: learning how to program it. For this, the inexpensive, easy-to-operate personal computer, entirely self-contained and relying on equipment immediately at the student's side, is an ideal instrument—much more "user friendly," as manufacturers like to say, than big machines. Yet even with a handy micro, programming can overwhelm the uninitiated. The programmer and computer must "speak" a common language.

In the early days of the digital computer, this was extremely difficult. The machine reduces all the information it receives, whether it arrives as letters, numbers or graphic symbols, into the simplest possible electronic statements: either a yes or a no, represented by pulses of high or low voltage. To command the machine in its own internal language meant writing out endless strings of ones or zeros, called bits and bytes, symbolizing those yes or no statements. But scientists soon began creating alternate languages for communicating with the machines that vaguely resemble everyday speech.

The most popular of these computer tongues is BASIC (for Beginner's All-purpose Symbolic Instruction Code). Developed at Dartmouth by Mathematician John Kemeny and his colleague Thomas Kurtz to let even the least mathematically gifted student converse with the university's computers, it is "understood" by virtually all of today's personal computers. To show just how easy the language is, Kemeny offers this extremely simple lesson in programming: tell the computer to find the square roots (i.e., the numbers that when multiplied by themselves, yield the original numbers) of eleven successive values, say 20 through 30.

The entire operation can be accomplished with a program of just four steps: 1FOR N = 20 T0 30




Translated into everyday language, the first line tells the computer to let N stand successively for 20 through 30. The second instructs the machine to print the first value of N (that is, the number 20), compute its square root (SQR) and print out the result. The third tells the computer to go on to each of the succeeding values, all the way through 30. Finally, the program tells the computer to call it a day, its job having been done. Even the smallest machine can do such calculations in a flash, compared with the hours of work they might require of human computers.

To preserve their creativity, the students can readily store their programs on magnetic tape or on a small, 45 r.p.m.-size plastic record called a floppy disc—which is not, as some parents believe, a new form of back injury. Then when the occasion arises for using the program again, the computer operator merely loads the

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10