Step 1. The following assembly code copies a string from source to target:

.data

source BYTE "This is the source string",0

target BYTE SIZEOF source DUP(0)

.code

mov esi,0 ; index register

mov ecx,SIZEOF source ; loop counter

L1:

mov al,source[esi] ; get char from source

mov target[esi],al ; store it in the target

inc esi ; move to next character

loop L1 ; repeat for entire string

mov edx, OFFSET source

call WriteString

mov edx, OFFSET target

call WriteString

Rewrite the program using indirect addressing rather than indexed addressing. [Hint] Use OFFSET operator to save the base address of source and target.

Step 2. Insert the following variables in your program:

.data

Uarray WORD 1000h, 2000h, 3000h, 4000h

Sarray SWORD -1, -2, -3, -4

Write instructions that use direct-offset addressing to move the four values in Uarray to the EAX, EBX, ECX, and EDX registers. When you follow this with a call DumpRegs statement, the following register values should display:

EAX=00001000 EBX=00002000 ECX=00003000 EDX=00004000

Next, write instructions that use direct-offset addressing to move the four values in Sarray to the EAX, EBX, ECX, and EDX registers. When you follow this with a call DumpReg statement, the following register values should display:

EAX=FFFFFFFF EBX=FFFFFFFE ECX=FFFFFFFD EDX=FFFFFFFC