Questions:
1- You have a PC with a 2 GHz processor, a system bus clocked at 400 MHz, and a 3 Mbps internal cable modern attached to the system bus. No parity or other error-checking mechanisms are used. The modern has a 64-byte buffer. After it receives 64 64 bytes, it stops accepting data from the network and sends a data ready interrupt to the CPU. When this interrupt is received, the CPU and OS perform the following actions:
a. The supervisor is called.
b. The supervisor calls the modern's data ready interrupt handler.
c. The interrupt handler sends a command to modern, instructing it to copy its buffer content to main memory.
d. The modern interrupt handler immediately returns control to the supervisor' without waiting for the copy operation to be completed.
e. The supervisor returns control to the process that was originally interrupted.
When the modern finishes the data transfer, it sends a transfer completed interrupt to the CPU and resumes accepting data from the network. In response to the interrupt, the CPU and OS perform the following actions:
a. The supervisor is called.
b. The supervisor calls the transfer completed interrupt handler.
c. The interrupt handler determines whether a complete packet is present in memory. If so, it copies the packet to a memory region of the corresponding application program.
d. The modern interrupt handler returns control to the supervisor.
e. The supervisor returns control to the process that was originally interrupted.
2- What is a font? What is pont size?
3- Describe the types of optical input devices. For what type of input is each device intended ?
4- What is a stack? Why is it needed?
5- How can a cache be used to improve performance when reading data from and writing data to a storage device ?
6- Music purchased from iTunes is encoded in the MP4 format. Investigate this format and compare it with the MP3 encoding method discussed in the chapter. Which encoding method offers the best tradeoff between compression ratio and audio quality? Which requires the most processing power for audio encoding ? Which addresses issues of copy protection, and how are these issues addressed?