CS609 Midterm Solved Subjective with References by Seher

Subjective (Year : 2013)

Q1. ((( inport((*lpt) +1)) & 0x80) == 0x80) which condition is checked? 2 marks

Answer: page #97 Condition will check whether the printing port is idle or not.

Q2. Which command used before changing the typematic and LEDS? 3 marks.

Answer: Page no: 181 0xF3 used for type matic rate oxED used for LEDS

Explain null modem? 5 marks

Answer: Page no: 122 If data is to be transferred from one computer to another through some media which can carry digital data then the modem can be eliminated and the UART on both computers can be interconnected. Such arrangement is called a NULL modem.

Keyboard writing protocol? 5 marks

Answer: Page no: 180

CS609 Midterm Subjective Solved with References · Year: 2013 · By: Sahar

Q1. write down the purpose of interrupt 11H.

Answer: Page no: 161 Interrupt 11H is used to determine the systems information. On return this service returns the systems info in AX register.

Q2. When we discuss flow control using RS232C. Which line is used for data transmission and reception?

Answer: Page no:110

terminal equipment) and DCE (Data communication equipment). Data is received through the RxD line. Data is send through the TxD line.

Q3. What the usage of coprocessor control word while testing for coprocessor?

Answer: Page no:16

should contain 11on initialization. The coprocessor status register stores the status of the coprocessor. Very much like the flags register in the microprocessor the Coprocessor status word can be used to determine the result of a comparison as shown in the slide.

Q4. Suppose we have got the status byte of LPT1 port usig BIOS function int 17H.Write the condition

Answer: 17H/00H Write a character on entry AH=00 AL=ASCII code DX=Interface# On exit AH=Status Byte in C language that can check the time out, transfer error and out of paper error.

Q5. Draw the status of Clock Status C register.

Answer: Page no: 146

Q6. Explain the purpose of UART.

Answer: Page no:107 The UART is a device used for asynchronous communications. UART is capable of encapsulating a byte that might be 5, 6, 7 or 8 bits wide in start and stop bits. Moreover it can attach an extra parity bit with the data for error detection. The width of stop bits may also vary.

Write Keyboard writing protocol?

Answer: Page no: 182 Keyboard writing Protocol