The Program That Starts First: teacher key

How Computers Work, grade 9 edition, written for 9th grade. Meet the translators, the stored-program idea and the operating system that starts first and runs every other program.

Read the book. Print this page for the key.

Questions and answers

1. What starts first when a computer boots up?
   • The operating system (answer)
   • A compiler
   • A pixel
2. What does the operating system give each program?
   • Its own machine code
   • Its own area of memory (answer)
   • Its own CPU family
3. What does round robin do?
   • Sorts files
   • Cools a chip
   • Runs a few instructions from each program in turn (answer)
4. Why must source code be translated?
   • Only machine code can run on the CPU (answer)
   • Computers cannot store it
   • It is too short
5. How is a bit usually held in a chip?
   • In a spiral of pits
   • In a memory cell set to high or low voltage (answer)
   • On a wheel

Words

• compiler: code translator
• cycle: repeating loop
• reprogrammable: can be changed
• supervisory: overseeing