Ch 12: Terminate and Stay Resident (TSR)

In-depth study of writing Terminate and Stay Resident (TSR) programs in assembly, preserving resident memory blocks, intercepting keyboard scancodes via INT 09h, and unhooking interrupt vectors cleanly.

127 Questions127 MCQs0 Short Questions0 Long Questions

🎯 Exam Practice Papers

CS401 - Computer Architecture and Assembly Language Programming Examination Practice

Timed practice exam simulation for CS401 - Computer Architecture and Assembly Language Programming.

Showing 31 – 40 of 127 Questions

Page 4 of 13

Q31

📝 Short Q📘 CS401📑 Lec 12🏷️ DOS EXEC Parameter Block (EPB) Structure (INT 21h AH=4Bh)Hard🔁⭐💡📄🎓VU🏛️VU

Describe the layout and structure of the EXEC Parameter Block (EPB) passed to MS-DOS INT 21h Service 4Bh (AH = 4Bh, AL = 00h) when loading and executing a child program.

💻 assembly Snippet

epb:
    dw 0           ; Inherit parent environment
    dd cmd_line    ; Pointer to command line tail
    dd fcb1        ; Pointer to FCB 1
    dd fcb2        ; Pointer to FCB 2

Q32

❓ MCQ📘 CS401📑 Lec 12🏷️ DOS Buffered Keyboard Input Structure (INT 21h AH=0Ah)Medium🔁⭐💡📄🎓VU🏛️VU

In a DOS buffered keyboard input structure (INT 21h Service 0Ah), which byte offset stores the count of characters actually read upon return?

💻 assembly Snippet

buffer: db 80, 0
times 80 db 0

A.First byte (Offset +0)
B.Second byte (Offset +1)
C.Third byte (Offset +2)
D.Fourth byte (Offset +3)

Q33

❓ MCQ📘 CS401📑 Lec 12🏷️ DOS Device Driver Attribute Word (Bit 15)Easy🔁⭐💡📄🎓VU🏛️VU

In an MS-DOS Device Driver Header, which bit in the 16-bit Device Attribute Word determines whether the driver represents a character device or a block device?

A.Bit 12
B.Bit 13
C.Bit 14
D.Bit 15

Q34

❓ MCQ📘 CS401📑 Lec 12🏷️ DOS Character Input Service (INT 21h AH=01h)Easy🔁⭐💡📄🎓VU🏛️VU

DOS INT 21h Service 01h reads a character from standard input with echo. In which register is the ASCII value returned?

💻 assembly Snippet

mov ah, 0x01
int 0x21

A.AL register
B.BL register
C.CL register
D.BH register

Q35

❓ MCQ📘 CS401📑 Lec 12🏷️ DOS Device Driver Header Attribute Word (Bit 15)Easy🔁⭐💡📄🎓VU🏛️VU

In an MS-DOS Device Driver Header, which bit in the 16-bit Device Attribute Word determines whether the device is a character device or a block device?

A.Bit 12
B.Bit 13
C.Bit 14
D.Bit 15

Q36

📝 Short Q📘 CS401📑 Lec 12🏷️ MS-DOS Device Driver Architecture and Header StructureMedium🔁⭐💡📄🎓VU🏛️VU

What are device drivers in operating systems? Explain their primary role and describe the device driver header structure in MS-DOS.

💻 assembly Snippet

driver_header:
    dd -1               ; Link to next driver
    dw 0x8000           ; Attribute word (Character device)
    dw strategy_routine ; Strategy offset
    dw interrupt_routine; Interrupt offset
    db 1                ; Units supported

Q37

📝 Short Q📘 CS401📑 Lec 12🏷️ Bitwise Logical Operations (AND, OR, XOR, NOT)Easy🔁⭐💡📄🎓VU🏛️VU

Explain how bitwise logical instructions (AND, OR, XOR, NOT) operate on registers in 8088 assembly language using 'AND AX, BX' as an example.

💻 assembly Snippet

and ax, bx

Q38

📝 Short Q📘 CS401📑 Lec 12🏷️ Bitwise AND and OR OperationsEasy🔁⭐💡📄🎓VU🏛️VU

Explain the bitwise AND and OR instructions in 8088 assembly language, detailing their operational behavior on corresponding bits and supported operand forms.

💻 assembly Snippet

and ax, bx
or byte [mem], 5

Q39

📝 Short Q📘 CS401📑 Lec 12🏷️ Bitwise XOR Instruction and Reversibility ApplicationsMedium🔁⭐💡📄🎓VU🏛️VU

Describe the operational characteristics of the bitwise XOR (Exclusive OR) instruction in 8088 assembly language. Why is XOR reversible, and what are its practical applications?

💻 assembly Snippet

xor ax, ax
xor byte [mem], 5

Q40

📝 Short Q📘 CS401📑 Lec 12🏷️ NOT Instruction and One's ComplementEasy🔁⭐💡📄🎓VU🏛️VU

Explain the operation of the bitwise NOT instruction in 8088 assembly language and highlight how it differs from AND, OR, and XOR.

💻 assembly Snippet

not ax
not byte [mem]

Ch 12: Terminate and Stay Resident (TSR)

CS401 - Computer Architecture and Assembly Language Programming Examination Practice

Mid Term Examination

Final Term Examination

CS401 - Computer Architecture and Assembly Language Programming Examination Practice

Mid Term Examination

Final Term Examination

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