Assembler

The assembler is named "as11". Once a program has been written and saved with an ASCII editor, it is ready for consumption by the assembler. The assembler forces a file naming convention on the source file, it must end in ".asm" In order to assemble a source (.asm) file, type "as11 <filename>.asm" and if no errors were found, the assembler will produce the object file <filename>.s19. This object file is ready for download to the Miniboard. However, if errors were found in the source file then no object file will be produced. You can force the assembler to produce a listing file (showing where the errors occurred) by using the -l command line option as in "as11 -l <filename>.asm" Then the file <filename>.lis will be produced. The programmer may view <filename>.lis with an ASCII editor to discover where the errors occurred. In the listing file they will be labeled with an all capitols warning "ERROR".

The assembler supports labels. Any word beginning in coulomb one of the source file is a label. Comments are the remainder of a line after all operands have been processed for a give mnemonic. A comment may also be a line with an asterisk in coulomb one. To form constants the assembler recognizes several formats of data:

• ASCII values preceded by a '
• Hex values preceded by a $
• Binary values preceded by a %
• Decimal value given

• + addition
• - subtraction
• * multiplication
• / division
• % mod
• & bitwise and
• | bitwise or
• ^ bitwise exclusive or

There are five Assembler directives:

• FCC form character constant
• FDB Form double byte
• RMB reserve memory block
• ORG Begin loading at this address
• EQU Equate a label to a numeric value.