Computer Science Canada ASCII, Machine Code, Basic Assembly Language |
| Author: | Okapi [ Wed Oct 24, 2007 1:09 pm ] |
| Post subject: | ASCII, Machine Code, Basic Assembly Language |
So I've to write a program to add two four digit values stored as ASCII strings. The strings are represented by values in decimal notation. The strings are stored at addresses $2000 and $2004. Store the result in d5 - and I need some help I need help with the thoery and instructions. I don't want anyone to do it for me, just maybe explain how/why. So far.. org $2000 * set the address at which the next instruction will be stored move.b $2000,d3 * move byte at address $2000 to d3 move.b $2004,d4 * move byte at address $2004 to d4 add d3,d4 * add information stored in d3 to information stored in d4 trap #0 * return to monitor Basically I don't understand the ASCII part, can someone exlpain? |
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| Author: | md [ Wed Oct 24, 2007 2:10 pm ] |
| Post subject: | RE:ASCII, Machine Code, Basic Assembly Language |
not knowing if this is MIPS, Intel (which it seems to be...) or something else; and not recognizing the assembler syntax... step 1 would be to convert your tow strings into integers; a simple function would work. step 2 is to add the two integers; that's as simple as loading them into registers (if they aren't there already) and calling add (or some form thereof). Lastly move the result into d5 if it isn't there already. ASCII to integer is actually pretty easy to do. Try writing it in C first, then convert the C code to assembly. |
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