CMSC 311 - Project #1

computer organization

c m s c 311
s u m m e r 2 0 0 2

Project #0 Clarifications

Thanks to B. Dunavant for pointing out these issues in the specs.

Initial correction: Commands should be numbered at 0, not 1. Primary output now fixed.
Don't worry too much about printing the spacing correctly. The system will ignore one or more blanks, so if you've reduced, say. 6 blanks to one, that's fine.
Modified the INVALID COMMAND to print the actual invalid command
Primary input/output posted at: ~ch1101/Proj/P0/primary.input and ~ch1101/Proj/P0/primary.input.
To submit:
~ch1101/submit p0.tar 0
Note: your output should match the output by using diff -bwi on your output and the primary output. If the only difference is blank lines, you should be able to submit fine.
Send email to: clin@umd5.umd.edu if you notice errors. I will fix them by Tuesday evening.
I will look over the code to make sure you have algorithms to convert numbers (as described in class) as opposed to using built-in functions to do the conversion from one base to another. However, if you found a built in way to display hex and octal, that will be fine.

Project 0 due Wednesday, June 12 at 11:59. However, you may wish to turn it in Tuesday, as usual (the primary should be ready late Monday or early Tuesday).
convert with floating point has the following representation.
convert 0.375_10 2
where the first number always has a decimal point and digits before and after the decimal point. This part is extra credit. Mostly going to check base 10 to base 2, but if you want to try to get it working from base 10 to other bases (and then from other bases to other bases), you can do so.
However, don't get too carried away, unless you feel you have the time.
When you see:
0x0A 0b1100 037
as inputs, the format for binary when read in, is not the same as the format when printed out. However, for hex and octal, the format is the same.
The inputs for little-endian and big-endian will never be symmetric, thus you can tell which is which based on the numbers. For example, the actual answer will never be: 0A 23 23 0A (which is symmetric).

For convert, the source is written as 1A23_12 when read in as input.
However, when printed as output, leave off the base subscript. Thus, if the source is 111_2 and the base is 10, then print:
```
Base  2: 111
Base 10: 5
```
You do not need to make the colons align, although it will be easier to read, if you do.
The cmmd instruction says that the bitstring can be of arbitrary length. However, you may assume this is smaller than 100 characters (for those of you who wish to use a static array).
Note: numbers are written as they are to be read by a user, not as they are stored in memory (except for commands that have to do with endian-ness). For example, when you see 0b10101000, the least significant bit is on the right, and the most significant bit on the left.

(June 6) When printing the name of the command, you can either print as the command was typed in (e.g., "eNdiAN") or you can print in all lowercase (e.g., "endian") or in all uppercase (e.g., "ENDIAN").
(June 6) Remove leading and trailing whitespaces in commands. Thus, " endian " should print as "[endian]". Leading whitespace are blanks up to the first non-blank character. Trailing whitespace are blanks after the last non-blank character up to the newline character.
(June 6) Any line with a command ends in a newline character.
(June 6) You may assume "cmmd" (where a value is printed in binary, octal, or hexadecimal) is a value which can be stored in a 4 byte unsigned int (meaning the value is between 0 and 2³² - 1). Furthermore, you may assume valid values (0 and 1 for binary, 0--7 for octal, and 0--F for hexadecimal)
(June 6) You should handle upper and lower case for "cmmd" (thus, 0b011 or 0B011, 0x11AB or 0X11AB).
(June 6) You should handle upper and lower case for hex input (although it will mostly be tested with uppercase). Thus, you should handle 0xBA10 as well as 0xba10 (and 0XBA10 and 0Xba10). Again, converting to lowercase should help.

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Last Modified: Wed Jun 5 10:38:37 EDT 2002