11/6 Daily Do Now

How were programs typically executed on computers in the 1940s and early 1950s?

• Programs were loaded automatically by an operating system.

• Programmers directly typed code into the computer's console.

• Programs were written on punch cards, manually fed into the computer by an operator, and run one at a time.

• Programs were shared and run simultaneously on multiple machines.

What was a key motivation for the development of early operating systems in the 1950s?

• To allow computers to connect to networks and share resources.

• To provide a user-friendly graphical interface for computer interaction.

• To automate the manual loading and execution of programs, which had become inefficient.

• To enable real-time interaction between users and computers.

What problem did device drivers solve for programmers in the era of widespread computers?

• They allowed programmers to write code in higher-level languages.

• They eliminated the need for physical peripheral devices.

• They provided a standardized way for programs to interact with various input/output hardware, abstracting away low-level details.

• They enabled computers to connect to the internet.

How does virtual memory address the challenge of managing memory for multiple programs running concurrently?

• It physically separates the memory of each program into distinct hardware modules.

• It allows each program to perceive its memory starting at address zero, while the operating system handles the complex physical remapping.

• It stores all program data on external storage devices instead of RAM.

• It requires programmers to manually track and allocate specific physical memory addresses for their programs.

What is the primary benefit of dynamic memory allocation for programs?

• Allows programs to directly access physical memory.

• Enables programs to have flexible memory sizes that appear continuous.

• Reduces the overall memory footprint of the operating system.

• Prevents malicious software from accessing program data.

What is the main purpose of memory protection in an operating system?

• To speed up memory access for all programs.

• To allow programs to share memory freely.

• To isolate programs from each other and prevent one from trashing another's memory.

• To encrypt memory contents for security.

What was a key difference in design philosophy between Multics and UNIX, as noted by Dennis Ritchie?

• Multics prioritized speed, while UNIX prioritized security.

• UNIX was designed for mainframe computers, while Multics was for personal computers.

• Multics was considered over-engineered with too many features, while UNIX aimed for a lean and compact design.

• UNIX supported multitasking, but Multics did not.

What significant feature was lacking in early operating systems like MS-DOS and early versions of Windows, leading to frequent system crashes?

• Graphical user interface.

• Multitasking capabilities.

• Strong memory protection.

• Support for multiple users.