How much time is spent scanning across each row of pixels during screen refresh on a raster system with resolution of 1280*800 and a refresh rate of 70 frames per second?

Suppose we have a byte addressable computer that has a 32-byte cache with 8 bytes per block. the memory address is 8 bits long. the system accesses memory addresses (in hex) in this exact order: 6e, b9, 17, e0, 4e, 4f, 50, 91, a8, ab, ad, 93, and 94. (a) assuming the cache is direct mapped, what memory addresses will be in cache block 2 after the last address has been accessed? (b) assuming the cache is direct mapped, what is the hit ratio for the entire memory reference sequence given, assuming the cache is initially empty? (c) assuming the cache is 2-way set associative with a lru replacement policy, what is the hit ratio?

Assume that there is a 4% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

The qwerty keyboard is the most common layout of keys on a keyboard