Please indicate whether each statement is True (T) or False (F). 1. Real-mode pr
ID: 3758209 • Letter: P
Question
Please indicate whether each statement is True (T) or False (F).
1. Real-mode programming is also known as 16-bit mode programming.
2. MS-DOS function calls are also called interrupts because they use the INT instruction.
3. Video memory begins at offset 00100h in the IBM-PC's memory.
4. The transient command processor always remains in memory at an address just above the DOS kernel.
5. The device names for parallel printer port 1 are both PRN and LPT1.
6. The INT instruction uses a value in the BX register to locate an entry in the interrupt vector table.
7. Video services are handled by INT 16h.
8. MS-DOS services are handled by INT 21h.
9. When a MS-DOS function needs to access the computer's hardware, it calls a function in the BIOS.
10. INT 21h, function 10h writes a string to standard output.
11. The < operator, when used at the MS-DOS command prompt, redirects the current program's input.
12. Writing data to a text file usually takes more CPU time than writing data to a binary file.
13. There is no INT 21h function that lets you set a file's I/O pointer past the end of a file.
14. The MS-DOS command tail is located in the data segment when a program begins to execute.
15. When a file is opened by an MS-DOS function, the function returns an integer handle. This handle must be used for all subsequent reading and/or writing to the file.
Explanation / Answer
1)Real-mode programming is also known as 16-bit mode programming --- True
2) MS-DOS function calls are also called interrupts because they use the INT instruction. --- True
3)Video memory begins at offset 00100h in the IBM-PC's memory. -- True offset of the new routine is written at 00100H
4)The transient command processor always remains in memory at an address just above the DOS kernel. -- False
5) The device names for parallel printer port 1 are both PRN and LPT1. - False
The device names for parallel printer port 1 are both PRN and LPT1 -- Dos refers to the different parts of the computer with special names called device parts each devoce connects to a different device LPT1, LPT2
6) The INT instruction uses a value in the BX register to locate an entry in the interrupt vector table. -- False
BX is known as the base register, as it could be used in indexed addressing.
Index Registers - These registers are used with the string instructions.
The BIOS typically sets up a real mode interrupt handler at this vector that provides video services.
8) MS-DOS services are handled by INT 21h. - True
The MS-DOS API is an API which originated with 86-DOS and is used in MS-DOS/PC DOS and other DOS-compatible operating systems. Most calls to the DOS API are invoked using software interrupt 21h (INT 21h). By calling INT 21h with a subfunction number in the AH processor register and other parameters in other registers, one invokes various DOS services.
9) When a MS-DOS function needs to access the computer's hardware, it calls a function in the BIOS. - True
10. INT 21h, function 10h writes a string to standard output. - false 10 h refers to Close file
11) The < operator, when used at the MS-DOS command prompt, redirects the current program's input. -- Redirect input -- True
12) Writing data to a text file usually takes more CPU time than writing data to a binary file. - False
13) There is no INT 21h function that lets you set a file's I/O pointer past the end of a file. - true 21h used to Random read
14. The MS-DOS command tail is located in the data segment when a program begins to execute. - True
15 When a file is opened by an MS-DOS function, the function returns an integer handle. This handle must be used for all subsequent reading and/or writing to the file. -- True