Back in the “old days” of DOS, you could only run one command-interpreter session at a time. Even though all CPUs since the 80286 were capable of running in Protected mode, MS-DOS ran the CPU in Real mode. This was done to preserve backward-compatibility with the old 8086 and 8088 CPUs. Use the Linux User Interface 19 In Protected mode, the CPU can run multiple virtual 8086 emulation sessions at the same time. In Real mode, the CPU emulates a fast 8086, which only allows one session to run at a time.

Don’t just skim them. Test item authors deliberately include responses that are almost correct, but not quite. ) The intent is to distract you away from the real answer. I know it sounds sneaky, but the intent is to make the exam such that you can’t divine the correct answer without really knowing your stuff. ■ Eliminate responses that are obviously wrong. Each item will have one or more responses that are blatantly wrong. ) Eliminate these answers and focus only on the responses that could be correct.

6. Return to the first console screen by selecting alt-f1. 7. Load the zsh shell by entering zsh at the prompt. 8. Return to your default shell by entering exit at the prompt. Now that you know how to access your shell, let’s talk about how you use it to run programs. Running Commands at the Shell Prompt Running a program or command from the shell prompt is relatively easy. It is done in the same manner as in DOS or within a command window in Windows. You just type the command or program file name at the shell prompt and press enter.