
{*******************************************************}
{                                                       }
{       Turbo Pascal Version 7.0                        }
{       Overlay Interface Unit                          }
{                                                       }
{       Copyright (C) 1988,92 Borland International     }
{                                                       }
{*******************************************************}

unit Overlay;

{$D-,I-,S-}

interface

const
  ovrOk = 0;
  ovrError = -1;
  ovrNotFound = -2;
  ovrNoMemory = -3;
  ovrIOError = -4;
  ovrNoEMSDriver = -5;
  ovrNoEMSMemory = -6;

const
  OvrResult: Integer = 0;
  OvrEmsPages: Word = 0;
  OvrTrapCount: Word = 0;
  OvrLoadCount: Word = 0;
  OvrFileMode: Byte = 0;

type
  OvrReadFunc = function(OvrSeg: Word): Integer;

var
  OvrReadBuf: OvrReadFunc;

procedure OvrInit(FileName: String);
procedure OvrInitEMS;
procedure OvrSetBuf(Size: LongInt);
function  OvrGetBuf: LongInt;
procedure OvrSetRetry(Size: LongInt);
function  OvrGetRetry: LongInt;
procedure OvrClearBuf;


