Assignment 2 Solutions

Part of the homework for 22C:60, Fall 2010
by Douglas W. Jones
THE UNIVERSITY OF IOWA Department of Computer Science

The problem: Convert the following values to the indicated base: (1 point)
a) 1010101111001101₂ to base 16
ABCD
b) 32330001₄ to base 16
EF01
c) 21505₈ to base 16
2345
d) 26505₁₀ to base 16
6789
e) A8CA₁₆ to base 10
43210
Hint: Some patterns should emerge to help you judge your answers.
The problem: Consider the value -123 (a negative decimal number). (1 point)
a) Convert it to a 12-bit signed magnitude binary number.
1000 0111 1011
b) Convert it to a 12-bit one's complement binary number.
1111 1000 0100
c) Convert it to a 12-bit two's complement binary number.
1111 1000 0101
d) Convert it to a 12-bit natural-biased binary number.
0111 1000 0101
e) Convert it to a 4-digit 10's complement decimal number.
9877
The Problem: Show the result of assembling the following into memory using the SMAL assembly language. Show the result in hexidecimal as a sequence of 32-bit words in memory: (1 point)
```
	H       17767
        B       "#"
	B       1
	W	32#24QNJFF
```
Hint: You can use the SMAL assembler to help you with this, but you will need to finish the job of packing the result into 32-bit words by yourself. Also, as in problem 1, when you get it right, the result should be obviously right.

Here is the assembler output:
```
        +000000: 4567                1          H       17767
        +000002: 23                  2          B       "#"
        +000003: 01                  3          B       1
        +000004: 89ABCDEF            4          W       32#24QNJFF
```
The above, packed into a sequence of 32-bit words, is:
```
         000000: 01234567
         000004: 89ABCDEF
```