Ch 17: Secondary Storage and Device Drivers

To retrieve parameters passed on the stack inside a subroutine, what is the simplest initial method available to assembly programmers?

pop ax

In x86 assembly language calling conventions, parameter stack cleanup can be performed by:

call my_func
add sp, 4

How many primitive block processing (string) instructions are provided in the 8088 microprocessor instruction set?

The unsigned multiplication instruction 'MUL' performs a multiplication of the source operand and which implied destination register?

mul bl

Any numeric digit value (0 through 9) can be converted into its corresponding ASCII character representation by adding which hexadecimal value?

add al, 0x30

Which flag in the FLAGS register controls the execution direction of string processing instructions, where clearing it moves from lower to higher memory addresses and setting it moves from higher to lower memory addresses?

cld
std

Which x86 assembly instruction decrements SP (the stack pointer) by two and then transfers a word from the source operand to the top of stack now pointed to by SP?

push bx

True or False: A typical stack in x86 architecture is defined as an area of computer memory with a fixed origin (base address) and a variable size (top of stack moves dynamically).

True or False: Local variables within a subroutine should be created on the stack when the subroutine is called and discarded immediately before returning.

sub sp, 4
add sp, 4

True or False: Both DS and ES segment registers can access Video Memory, but assembly programmers commonly preserve DS for data variables and load ES with the video segment address.

mov ax, 0xb800
mov es, ax