When a user program makes a system call to read or write a disk file, it provides an indication of which file it wants, a pointer to the data buffer, and the count. control is then transferred to the os, which calls the appropriate driver. suppose that the driver starts the disk and terminates until an interrupt occurs. in the case of reading from the disk, obviously the caller will have to be blocked (because there are no data for it). what about the case of writing to the disk? need the caller be blocked awaiting completion of the disk transfer? explain.

Aisha has finished working on a word processing document that contains 15 pages. she has added some special elements in the first three pages, page 9 and 10, and page 15 from the document. she wants to print only these pages to see how they look. which option is the correct way to represent (in the print dialog box) the pages that aisha wants to print?

Look at the far left lane in the picture. explain what the red car is doing and what it needs to do to travel safely.

Write a program that defines symbolic names for several string literals (chars between quotes). * use each symbolic name in a variable definition. * use of symbolic to compose the assembly code instruction set can perform vara = (vara - varb) + (varc - vard); ensure that variable is in unsigned integer data type. * you should also further enhance your symbolic logic block to to perform expression by introducing addition substitution rule. vara = (vara+varb) - (varc+vard). required: debug the disassembly code and note down the address and memory information.