2. D75P 34R - HNC Computer Architecture Week 7 A Mini Test! © C Nyssen/Aberdeen College 2004 All images © C Nyssen /Aberdeen College unless otherwise stated Timer, decision © Microsoft ISO table © and courtesy of IBM Prepared 9/11/04

3. This lecture will consist of 10 questions on a timer. The questions are of equivalent difficulty to the Outcome 1 paper. You have 1½ minutes to answer each one. After 1 minute a dinosaur will appear, to let you know that you only have 30 seconds left before the slide changes! At the end we will check the answers, and anything that you did not understand will be expanded on the whiteboard. You need six or more questions correct for a pass. Ready to go?...........

4. Question 1. Take the following pair of binary numbers 1100 1010 0101 0000 1011 0111 1100 1100 And apply this gate to get the answer… a.1000 0010 0100 0000 b.1111 1111 1101 1100 c.0000 0000 0010 0011 d.0111 1101 1011 1111

5. Question 2. What is the binary storage of the number -329 formatted to 10 bits and using 2’s complement? a. 11 0100 1001 b. 10 1011 0110 c. 10 1011 0111 d. 01 0100 1001

6. Question 3. What is the hexadecimal number C2Ah in denary? a.3094 b.3114 c.40902 d.1100 0010 1010

7. Question 4. What is the binary value 1100 0111 0110 0010 in hexadecimal? a.B762h b.C762h c.D762h d.D772h

8. Question 5. The signed binary number 1101 1001 1001 in denary is – a.-615 b.+615 c.-1433 d.+3481

9. Question 6. Subtract the second number from the first one using 2’s complement and addition. 1101 1100 0110 0100 0111 0111 a.0010 0011 1101 b.1001 0100 1110 c.1001 0100 1111 d.0110 1011 0000

10. Question 7. Add the hexadecimal values E550h and F19Dh. a.176EDh b.1B6FDh c.1C6EDh d.1D6CDh

11. Question 8. Apply an XOR gate to the following pair of numbers. 1101 1100 0101 0011 0101 0101 a.1101 1101 0101 0111 b.0101 0100 0101 0001 c.0010 0010 1010 1000 d.1000 1001 0000 0110

12. Question 9. What is the number 4771 in hexadecimal? a.12A3h b.1CA3h c.2933h d.2CA3h

13. Question 10. The Greek character Ω (omega) could be represented by using ISO 8859-7 and the binary value a.U+D9 b.U+BC c.1101 1001 d.1011 1100

14. So let’s see how you got on……

15. Question 1. Take the following pair of binary numbers 1100 1010 0101 0000 1011 0111 1100 1100 And apply this gate to get the answer… a.1000 0010 0100 0000 b.1111 1111 1101 1100 c.0000 0000 0010 0011 d.0111 1101 1011 1111 The correct answer was d. It is a NAND gate!

16. Question 2. What is the binary storage of the number -329 formatted to 10 bits and using 2’s complement? a. 11 0100 1001 b. 10 1011 0110 c. 10 1011 0111 d. 01 0100 1001 +329 would be 01 0100 1001 reverse it…10 1011 0110 add 1 to the LSB10 1011 0111 so the answer was c.

17. Question 3. What is the hexadecimal number C2Ah in denary? a.3094 b.3114 c.40902 d.1100 0010 1010 C or 12 times 256 is 3072 2 times 16 is 32 A or 10 times 1 is 10 Add all together to get 3114 So the answer was b.

18. Question 4. What is the binary value 1100 0111 0110 0010 in hexadecimal? a.B762h b.C762h c.CF62h d.D772h 1100 is 12 or C 0111 is 7 0110 is 6 0010 is 2 The correct answer is C762h - b.

19. Question 5. The signed binary number 1101 1001 1001 in denary is – a.-615 b.+615 c.-1433 d.+3481 As it is a signed number, the leading 1 tells us that it must be negative! Reverse all the remaining digits to get 010 0110 0110. Add 1 to the LSB to get 010 0110 0111. Convert back - (1 + 2 + 4 + 32 + 64 + 512) = 615. So the answer was a.

20. Question 6. Subtract the second number from the first one using 2’s complement and addition. 1101 1100 0110 0100 0111 0111 a.0010 0011 1101 b.1001 0100 1110 c.1001 0100 1111 d.0110 1011 0000 Reverse the second number and add 1 to the LSB- 1011 1000 1001 Add the two numbers….. 1101 1100 0110 1011 1000 1001 1001 0100 1111 The answer was c.

21. Question 7. Add the hexadecimal values E550h and F19Dh. a.176EDh b.1B6FDh c.1C6EDh d.1D6EDh E 5 50 F 1 9D 29 6 14 or E D The 29 becomes 13, or D, carry 1…. The answer was 1 D 6 E D h - option d.

22. Question 8. Apply an XOR gate to the following pair of numbers. 1101 1100 0101 0011 0101 0101 a.1101 1101 0101 0111 b.0101 0100 0101 0001 c.0010 0010 1010 1000 d.1000 1001 0000 0110 Remember that the XOR gate is the one that looks for differences in the inputs! The correct answer was d.

23. Question 9. What is the number 4771 in hexadecimal? a.12A3h b.1CA3h c.2933h d.2CA3h To do this without a calculator, you can set up some Hexadecimal columns….. 4096’s256’s16’s1’s We will get one lot of 4096 out of the 4771, leaving 675. (675-256) = 419. (419-256) = 163. So that’s 2 lots of 256. We will get 10 lots of 16 out of 163, leaving 3 over…. So the answer is 1 2 A 3 h. Answer a.

24. Question 10. The Greek character Ω (omega) could be represented by using ISO 8859-7 and the binary value a.U+D9 b.U+BC c.1101 1001 d.1011 1100 The answer was D9 in hex - or 1101 1001. Answer c.

25. So how was your score? If you got……. 8 - 10 …. Well done! You are a genius! 6 or 7 …. Congratulations! You should have no trouble at all with the real assessment! 4 or 5 …. Unfortunate! You need to do a wee bit more work between now and next week... 3 or less …. REVISE ALL OF THE LECTURES BEFORE NEXT WEEK!