AS(1)                        (PDP11)                        AS(1)

          as - assembler

          as [ - ] [ -o objfile ] file ...

          As assembles the concatenation of the named files.  If the
          optional first argument - is used, all undefined symbols in
          the assembly are treated as global.

          The output of the assembly is left on the file objfile; if
          that is omitted, a.out is used.  It is executable if no
          errors occurred during the assembly, and if there were no
          unresolved external references.

          /lib/as2       pass 2 of the assembler
          /tmp/atm[1-3]? temporary
          a.out          object

          ld(1), nm(1), adb(1), a.out(5)
          UNIX Assembler Manual by D. M. Ritchie

          When an input file cannot be read, its name followed by a
          question mark is typed and assembly ceases.  When syntactic
          or semantic errors occur, a single-character diagnostic is
          typed out together with the line number and the file name in
          which it occurred.  Errors in pass 1 cause cancellation of
          pass 2.  The possible errors are:

          )  Parentheses error
          ]  Parentheses error
          <  String not terminated properly
          *  Indirection used illegally
          a  Error in address
          b  Branch instruction is odd or too remote
          e  Error in expression
          f  Error in local (`f' or `b') type symbol
          g  Garbage (unknown) character
          i  End of file inside an if
          m  Multiply defined symbol as label
          o  Word quantity assembled at odd address
          p  `.' different in pass 1 and 2
          r  Relocation error
          u  Undefined symbol
          x  Syntax error

     AS(1)                        (PDP11)                        AS(1)

          Syntax errors can cause incorrect line numbers in following