Chapter 2

What is the purpose of the 8259A PIC controller?

The 8259A PIC controller handles external interrupts from hardware devices such as the keyboard, system clock, and disk drives.

What characteristics distinguish BIOS-level input/output?

BIOS function communicate directly with the system hardware. They are independent of the operating system.

Name all eight 32-bit general purpose registers.

EAX, EBX, ECX, EDX, ESI, EDI, ESP, EBP

In 32-bit mode, aside from the stack pointer (ESP), what other register points to variables on the stack?

EBP

Which flag is set when the result of signed arithmetic operation is either too large or to small to fit into the destination?

Overflow Flag

On a 32-bit processor, how many bits are contained in each floating-point data register?

80

At which levels can an assembly language program manipulate input/output?

Applicator Program, OS, BIOS, Hardware.

Which flag is set when the result of unsigned arithmetic operation is to long to fit into the destination?

Carry Flag

Name at least four CPU status flags.

Carry Flag, Overflow Flag, Sign Flag, Zero Flag.

Which part of the CPU performs floating-point arithmetic?

FPU

True/False: When a register operand size is 32 bits and the REX prefix is used, the R8D register is available for programs to use.

False.

What special purpose does the ECX register serve?

Loop counter.

What are the x86 processor's three basic modes of operation?

Real-address mode, Protected mode, and System Management mode.

Describe SRAM and its most common use.

SRAM is used primarily for expensive high-speed cache memory. It does not have to be refreshed. CPU cache memory is comprised of SRAM.

Which flag is set when an arithmetic or logical operation generates a negative result?

Sign Flag.