SIC XE Assembler Documentation - NicDuncanUNF/SIC-XE-ASSEMBLER GitHub Wiki

=====Summary===== Created by Nic Duncan, Paul Davis, Brent Melby, and Kaitlyn Turner This program is an assembler that creates object code for the SIC-XE assembly language.

=====headers.h===== Used to initialize all functions and libraries used throughout the program.

=====directives.c===== isADirective: Used to check if an inserted string matches a known system directive.

=====symbols.c===== IsAValidSymbol: Checks an inputted symbol against SIC-XE criteria. symbolExists: Searches a symbol table to make sure matching symbol does not exist already. addSymbol: Finds the next free slot in the symbol table and inserts the validated symbol.

=====instructions.c===== getOpcode: gets an equivalent opcode from a given instruction. IsAnInstruction: Returns a Boolean if the given string is a valid instruction or not. getInstrMovement: Returns the byte movement/format a given instruction uses.

=====objectcodes.c===== generateObjectcode: takes in instruction, token, location of instruction, and location of next instruction. Determines format of instruction and returns object code for instruction and length separated by a coma for use in main function. EX. ABCDEF,03 hexToBin: Converts a hexedecimal input to binary. binToHex: Converts a binary input to hexedecimal.

=====main.c===== main: Where pass 1 and pass 2 reside. updateLocation: Gets the location counter movement from each line. chopPrefix: Removes a prefix character such as +, #, or @ from a given input.

=====Error handling===== Pass 1: No empty lines present in the file Ensuring the program does not exceed the SIC-XE memory limit of 2^20 bytes or 0x100000 bytes. Validating that symbols meet SIC-XE's specifications such as starting with appropriate characters or being in all capital characters. Watch for duplicate symbol creation.

Pass 2: Check that valid symbol is referenced by format 3 instructions. Ensure that valid instructions and directives are used.

=====Limitations===== Max SIC-XE program size: 2^20 bytes, or 0x100000 bytes Maximum Symbol Table size: 1024 Max T records: 1024 Max M records: 1024 Will only output object code a SICXE machine can utilize. Programs cannot be used by SIC machines.