Keskustelu: Koodit: EMS moduli

unit OSMOEMS;   (* Version 1.0 *)

interface

const sivunkoko=16384; { 16k }

function osmoemsexists:boolean;
function osmoemspages:word;
procedure osmogetems(pages:word; var handle,pageframe:word);
procedure osmomapems(handle,logpage:word; physpage:byte);
procedure osmofreeems(handle:word);

var emsvirhe:integer;

implementation

const emmint=$67;
      dosint=$21;
      getpageframe=$41;
      getfreepages=$42;
      allocpages=$43;
      mappages=$44;
      deallocpages=$45;
      getversion=$46;
      statusok=0;

function osmoemsexists:boolean;
var emmdev,intdev:string[8]; a,b:word;
begin
 intdev:=''; emmdev:='EMMXXXX0';
 asm
  mov ah,035h
  mov al,emmint
  int dosint
  mov b,es
 end;
 for a:=10 to 17 do intdev:=intdev+chr(mem[b:a]);
 if intdev=emmdev then osmoemsexists:=true else osmoemsexists:=false;
end;

function osmoemspages:word; assembler;
asm
 mov ah,getfreepages
 int emmint
 mov al,ah
 mov ah,0
 mov emsvirhe,ax
 mov ax,bx  { hae vapaat ems sivut }
end;

procedure osmogetems(pages:word; var handle,pageframe:word);
var a,b:word;
begin
 a:=pages;
 asm
  mov ah,getpageframe
  int emmint
  mov b,bx  { ems sivu framen osoite }
  mov ah,allocpages
  mov bx,a
  int emmint
  mov a,dx  { ems kahva }
  mov al,ah
  mov ah,0
  mov emsvirhe,ax
 end;
 handle:=a;
 pageframe:=b;
end;

procedure osmomapems(handle,logpage:word; physpage:byte);
var a,b:word; c:byte;
begin
 a:=handle; b:=logpage; c:=physpage;
 asm
  mov ah,mappages
  mov dx,a
  mov bx,b
  mov al,c
  int emmint
  mov al,ah
  mov ah,0
  mov emsvirhe,ax
 end;
end;

procedure osmofreeems(handle:word);
var a:word;
begin
 a:=handle;
 asm
  mov ah,deallocpages
  mov dx,a
  int emmint
  mov al,ah
  mov ah,0
  mov emsvirhe,ax
 end;
end;

end.