!
! Undeclare 'ENQ' since it is already defined in MONSYM.
!

UNDECLARE ENQ;						

!
! INCLUDE FILES:
!

REQUIRE  'BLI:MONSYM';					! TOPS-20 symbols

!
! JSYS definitions
!

LITERAL
    $BFADR	=	0,				! TOPS-10 symbols for TOPS-10/TOPS-20 code
    $BFPTR	=	1,
    $BFCTR	= 	2,

    t20$k_skip		=	1,
    t20$k_non_skip	=	-1,
    X20$K_BUFFER_SZ	=	128,
    X20$K_MAX_SPEC	=	219,
    X20$K_CHAR_SIZE 	=	%O'070000000000',
    X20$K_RIGHT_HLF	=	%O'000000777777',
    X20$K_LEFT_HLF	=	%O'777777000000',
    X20$K_WORD_SIZE	=	%O'440000000000';


!
! TOPS-20 I/O Interface Macros
!

MACRO
    $X20_ASCIZ( string_descr, work_space ) =		! Copy a string into a given area and make it ASCIZ.
	BEGIN
	IF ( .string_descr[STR$H_LENGTH] + 1 ) GTR	! If the string will not fit in the work area,
		(%ALLOCATION(work_space) * 5)		!
	THEN						!
	    0						! return an error code to the caller.
	ELSE
	    BEGIN
    	    CH$MOVE( .string_descr[STR$H_LENGTH],	! Copy the given string
		     .string_descr[STR$A_POINTER],	!
		     CH$PTR( work_space ) );		! into the work area,
							!
 	    CH$WCHAR( 0, CH$PLUS(CH$PTR(work_space),	! make it ASCIZ.
		         .string_descr[STR$H_LENGTH]) );
	    1						! Return a successful completion code to the caller.
	    END
	END %,

    $T20_CLOSF( flags_jfn, error_bits ) =		! Close the file(s).
	BEGIN
	REGISTER $t20$ac1 = 1;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = flags_jfn;
	$t20$status = JSYS( t20$k_skip, CLOSF, $t20$ac1 );
	%IF NOT %NULL( error_bits )
	%THEN
	    error_bits = .$t20$ac1;			! Return the error code.
	%FI
	.$t20$status
	END %,

    $T20_DELF( jfn, error_bits ) =			! Delete the file.
	BEGIN
	REGISTER $t20$ac1 = 1;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = jfn;
	$t20$status = JSYS( t20$k_skip, DELF, $t20$ac1 );
	%IF NOT %NULL( error_bits )
	%THEN
	    error_bits = .$t20$ac1;			! Return the error code.
	%FI
	.$t20$status
	END %,

    $T20_GETER( process_handle, error_bits ) =		! Get the most recent error.
	BEGIN
	REGISTER $t20$ac1 = 1, $t20$ac2 = 2;
	BUILTIN JSYS;
	$t20$ac1 = process_handle;
	JSYS( t20$k_non_skip, GETER, $t20$ac1, $t20$ac2 );
	error_bits = .$t20$ac2 AND x20$k_right_hlf;	! Return the error code.
	END %,

    $T20_GTJFN( options, file_spec, jfn_error ) =	! Get JFN
	BEGIN
	REGISTER  $t20$ac1 = 1, $t20$ac2 = 2;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = options;
	$t20$ac2 = file_spec;
	$t20$status = JSYS( t20$k_skip, GTJFN, $t20$ac1, $t20$ac2 );
	IF .$t20$status					! If the open was successful,
	THEN						!
	    jfn_error = .$t20$ac1 AND x20$k_right_hlf	! just save the JFN,
	ELSE						! otherwise,
	    jfn_error = .$t20$ac1;			! return the error code.
	.$t20$status
	END % ,

    $T20_HALTF =					! Halt the process
	BEGIN
	BUILTIN JSYS;
	JSYS( 0, HALTF );
	END % ,

    $T20_OPENF( jfn, options, error_bits ) =		! Open the file.
	BEGIN
	REGISTER  $t20$ac1 = 1, $t20$ac2 = 2;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = jfn;
	$t20$ac2 = options;
	$t20$status = JSYS( t20$k_skip,  OPENF, $t20$ac1, $t20$ac2 );
	%IF NOT %NULL( error_bits )
	%THEN
	    error_bits = .$t20$ac1;			! Return the error code.
	%FI
	.$t20$status
	END % ,

    $T20_PBIN( character ) =				! Input a byte from the primary input designator(TTY:).
	BEGIN
	REGISTER $t20$ac1 = 1;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$status = JSYS( t20$k_non_skip, PBIN, $t20$ac1 );
	character = .$t20$ac1;				! Return the byte.
	.$t20$status
	END % ,

    $T20_PSOUT( string_pointer ) =			! Output to primary output designator(TTY:).
	BEGIN
	REGISTER $t20$ac1 = 1;
	BUILTIN JSYS;
	$t20$ac1 = string_pointer;
	JSYS( t20$k_non_skip, PSOUT, $t20$ac1 )
	END %,

    $T20_RDTTY( string_pointer, options,		! Input a string from the TTY:.
		 prompt_pointer,updated_ptr,bits_count ) =
	BEGIN
	REGISTER $t20$ac1 = 1, $t20$ac2 = 2, $t20$ac3 = 3;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = string_pointer;
	$t20$ac2 = options;
	$t20$ac3 = prompt_pointer;
	$t20$status = JSYS( t20$k_skip, RDTTY, $t20$ac1, $t20$ac2, $t20$ac3 );
	updated_ptr = .$t20$ac1;			! Return the updated pointer.
	bits_count = .$t20$ac2;				! Return any error code and the count.			
	.$t20$status
	END % ,

    $T20_RESET =					! Reset and initialize the current process
	BEGIN
	BUILTIN JSYS;
	JSYS( 0, RESET );
	END % ,

    $T20_RLJFN( jfn ) = 				! Release  JFN(s).
	BEGIN
	REGISTER $t20$ac1 = 1;
	BUILTIN JSYS;
	$t20$ac1 = jfn;
	JSYS( t20$k_skip, RLJFN, $t20$ac1 );
	END %,

    $T20_RMAP( process, page, access ) =		! Returns the accessibility of a page.
	BEGIN
	REGISTER $t20$ac1 = 1, $t20$ac2 = 2;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = (process)^18 + (page);
	$t20$status = JSYS( t20$k_non_skip, RMAP, $t20$ac1, $t20$ac2 );
	access = .$t20$ac2;
	.$t20$status
	END %,

    $T20_RNAMF( old_jfn, new_jfn, error_bits ) =	! Rename an existing file.
	BEGIN
	REGISTER  $t20$ac1 = 1, $t20$ac2 = 2;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = old_jfn;
	$t20$ac2 = new_jfn;
	$t20$status = JSYS( t20$k_skip,  RNAMF, $t20$ac1, $t20$ac2 );
	%IF NOT %NULL( error_bits )
	%THEN
	    error_bits = .$t20$ac1;			! Return the error code.
	%FI
	.$t20$status
	END % ,

    $T20_SFPTR( jfn, pointer ) =			! Adjust the file pointer.
	BEGIN
	REGISTER $t20$ac1 = 1, $t20$ac2 = 2;
	BUILTIN JSYS;
	$t20$ac1 = jfn;
	$t20$ac2 = pointer;
	JSYS( t20$k_skip, SFPTR, $t20$ac1, $t20$ac2 );
	END %,


    $T20_SIN( jfn, pointer,				! String input.
		 number_of_bytes, terminator, counter ) =
	BEGIN						
	REGISTER $t20$ac1 = 1, $t20$ac2 = 2, $t20$ac3 = 3, $t20$ac4 = 4;
	BUILTIN JSYS;
	LOCAL $t20$status;
	$t20$ac1 = jfn;
	$t20$ac2 = pointer;
	$t20$ac3 = number_of_bytes;
	$t20$ac4 = terminator;
	$t20$status = JSYS( t20$k_non_skip, SIN,  $t20$ac1, $t20$ac2, $t20$ac3, $t20$ac4 );
	counter = .$t20$ac3 + ABS(number_of_bytes);	! Return the number of bytes transferred.
	.$t20$status
	END % ,

    $T20_SOUT( jfn, pointer,				! String output.
		 number_of_bytes, terminator ) =
	BEGIN						
	REGISTER $t20$ac1 = 1, $t20$ac2 = 2, $t20$ac3 = 3, $t20$ac4 = 4;
	BUILTIN JSYS;
	$t20$ac1 = jfn;
	$t20$ac2 = pointer;
	$t20$ac3 = number_of_bytes;
	$t20$ac4 = terminator;
	JSYS( t20$k_non_skip, SOUT,  $t20$ac1, $t20$ac2, $t20$ac3, $t20$ac4 )
	END %;