(* MAS Storage definition module.
The intention in setting up this module is to
encapsulate all processor and RAM--storage dependencies.
*)

DEFINITION MODULE MASSTOR;
(* Import lists and Definitions *)

  FROM MASELEM IMPORT GAMMAINT;

  FROM Portab IMPORT STRING;

(* error indicators *)
  CONST
    spotless = 0;
    harmless = 1;
    severe = 2;
    fatal = 3;
    confusion = 9;

  TYPE
    LIST = GAMMAINT;
    P0 = PROCEDURE();

  VAR   BETA, BETA1, SIL : LIST;
	NU, NORMNU, EMSNUP, EMSNU, 
        GCC, GCCC, GCM, RHO, TAU, TAU0 : GAMMAINT;
	emsInUse : BOOLEAN;
        SPACEB, SPACEB1 : GAMMAINT;

    DebugProcessor : P0;
                        (* procedure called by ERROR if debug requested *)

    history : INTEGER;
                       (* highest error level encountered so far. *)

PROCEDURE ADV(L : LIST; VAR a, LP : LIST);
(*Advance.  L is a non-null list.  a=FIRST(L) and LP=RED(L). *)


PROCEDURE CELLS(): GAMMAINT;
(*Cells. Returns the used cells since storage initialization. *)


PROCEDURE CLOCK(): GAMMAINT;
(*Clock. Returns the current CPU clock reading in seconds.
At ATARI ST the clock is in 2 seconds intervalls. *)


PROCEDURE COMP(a, L : LIST): LIST;
(*Composition.  a is an object.  L is a list.  Returns the 
composition of a and L. *)


PROCEDURE DEQUE(L : LIST): LIST;
(*Dequeue.  L is a non empty queue representing list.  Returns a, the 
first object from the queue. L is updated. *)


PROCEDURE EMPTYQUE(M : LIST): BOOLEAN;
(*Empty Queue.  Tests if a queue is empty. *)


PROCEDURE ENQUE(a, L : LIST);
(*Enqueue.  a is an object.  L is a queue representing list. Appends a
to the quque L. *)


PROCEDURE ERROR(a : INTEGER; s : STRING);
(*Error. An error of severity a and indication s is reported. *)


PROCEDURE ErrorHandler(a : P0): GAMMAINT;
(*Error handler. Any error reported by the ERROR procedure is catched. *)


PROCEDURE FIRST(L : LIST): LIST;
(*First.  L is a non-null list.  a is the first element of L. *)


PROCEDURE NEWQUE(): LIST;
(*New Queue.  Returns a new empty queue. *)


PROCEDURE GENPROCESS(P : PROC; VAR S : ADDRESS; n : BOOLEAN);
(*Generate a new process. The process working space is allocated unter 
control of the garbage collector if n is TRUE, else it is assumed that 
the last working space is reused. P is a parameter less procedure,
S is the address of the generated process. If not enough space is 
available an error ocours. *)


PROCEDURE INV(L : LIST): LIST;
(*Inverse.  L is a list.  The inverse of L is returned.  The list L is
modified. *)


PROCEDURE LENGTH(L : LIST): GAMMAINT;
(*Length.  L is a list.  Returns length(L).*)


PROCEDURE LIST1(a : LIST): LIST;
(*List, 1 element.  a is an object.  L is the list (a). *)


PROCEDURE LISTVAR(VAR L : LIST);
(*List variable.  L is a list.  The address of L is made accessible
to the garbage collector. *)


PROCEDURE RED(L : LIST): LIST;
(*Reductum.  L is a non-null list.  Returns the reductum of L. *)


PROCEDURE SFIRST(L, a : LIST);
(*Set first.  L is a non-null list.  a is an object.  The first
element of L is changed to a. *)


PROCEDURE SRED(L, LP : LIST);
(*Set reductum.  L is a non-null list.  LP is a list.  The reductum
of L is changed to LP. *)


PROCEDURE SAVEPROCESS();
(*Save current process. Prepare transfer of two processes
unter the control of the garbage collector. *)


PROCEDURE TIME(): GAMMAINT;
(*Time. Returns the CLOCK minus the garbage collection time TAU.
At ATARI ST the clock is in 2 seconds intervalls. *)


PROCEDURE addEmsToAvail(): LIST;
(*Adds EMS-memory to AVAIL list. The number of EMS-cells
added is returned. *)


(* Dos-Interrupt Funktionen, in Topspeed-Modula nicht direkt verfgbar *)
PROCEDURE InputReady():   BOOLEAN;
PROCEDURE ReadKybdNoEcho(VAR c : CHAR);
PROCEDURE saveCellSpace(VAR adr : ADDRESS; VAR amnt : CARDINAL) : BOOLEAN;
PROCEDURE restoreCellSpace() : BOOLEAN;
PROCEDURE AddressToPhys(Adresse : ADDRESS): GAMMAINT;
PROCEDURE GetStackAdr(): GAMMAINT;


END MASSTOR.