Module #2 Study Deck

Question 1

How many bytes long is a DWORD (doubleword) on x86 systems?

Answer 1

4

Question 2

Operands may be any of the following: (select all that apply)
* non-register reserved word
* variable name (memory)
* constant or constant expression
* register name

Answer 2

• variable name (memory)
• constant or constant expression
• register name

Question 3

MASM is case-sensitive
True / False

Answer 3

False

Question 4

A procedure is declared using the _____ and ____ directives.
* START and END
* BEGIN and END
* PROCEDURE and END
* PROC and ENDP

Answer 4

• PROC and ENDP

Question 5

Which of the following BYTE declarations are allowed in MASM? (Check all that apply)

• myByte4 BYTE “nested ‘quotes’ “
• myByte3 BYTE ‘simple ‘quotes’ ‘
• myByte5 BYTE ‘W’,’o’,’r’,’s’,’t’,’!’,0
• myByte1 BYTE “Hot “, ‘Dog’, 33, 0
• myByte2 BYTE ‘Fancy’

Answer 5

• myByte4 BYTE “nested ‘quotes’ “
• myByte5 BYTE ‘W’,’o’,’r’,’s’,’t’,’!’,0
• myByte1 BYTE “Hot “, ‘Dog’, 33, 0
• myByte2 BYTE ‘Fancy’

Question 6

Code labels may only appear on lines with no instructions.
True / False

Answer 6

False

Question 7

By default, code labels are visible only within the procedure in which they are assigned (created).
True / False

Answer 7

True

Question 8

Which of the following are valid uses of the XCHG instruction? (check any/all that apply)

• XCHG reg,reg
• XCHG imm,reg
• XCHG reg,imm
• XCHG reg,mem
• XCHG mem,mem
• XCHG mem,reg
• XCHG imm,imm
• XCHG imm,reg

Answer 8

• XCHG reg, reg
• XCHG reg, mem
• XCHG mem,reg

Question 9

After the following MASM code is executed:

MOV EAX, 93
MOV EBX, 13
MOV EDX, 0
DIV EBX

What is the value in the EAX register (in decimal)?

What is the value in the EBX register (in decimal)?

What is the value in the EDX register (in decimal)?

Answer 9

What is the value in the EAX register (in decimal)? 7
What is the value in the EBX register (in decimal)? 13
What is the value in the EDX register (in decimal)? 12

Question 10

Which directive is used when defining 64-bit IEEE long reals?
REAL64
REAL
REAL8
REAL4

Answer 10

REAL8

Question 11

The following is a valid data definition statement:

str1 \
BYTE “This string is quite long!”, 0

True / False

Answer 11

True

Question 12

MASM will throw an error when assembling the following data segment:

.data
myChecker BYTE 12h
BYTE 34h
BYTE 56h
BYTE 78h
BYTE 90h

True / False

Answer 12

False

Question 13

The following data segment starts at memory address 1000h (hexadecimal)

.data
printString   BYTE    "Assembly is fun",0
moreBytes     BYTE    10 DUP(0)
dateIssued    DWORD   ?
dueDate       DWORD   ?
elapsedTime   WORD    ?

What is the hexadecimal address of dueDate?

1010h
101Eh
101Ah
1030h

Answer 13

101Eh

Question 14

The following data segment starts at memory address 2200h (hexadecimal)
~~~
.data
printString BYTE “MASM is fun”,0
moreBytes BYTE 25 DUP(0)
dateIssued DWORD ?
dueDate DWORD ?
elapsedTime WORD ?
~~~
What is the hexadecimal address of dueDate?
2225h
2241h
2229h
220Ch

Answer 14

2229h

Question 15

Which library procedure sets the Zero flag if the AL register contains the ASCII code for a decimal digit (0–9)?

Answer 15

IsDigit

Question 16

Which library procedure generates a 32-bit pseudorandom integer in a caller-specified range?

Answer 16

RandomRange

Question 17

Which register contains the starting address of data when calling DumpMem?
ECX
EDX
EBX
EAX
ESI
EDI

Answer 17

ESI

Question 18

Which library procedure returns the number of milliseconds elapsed since midnight?

Answer 18

GetMseconds