CPUTYPE.PAS

Unit CPUTYPE;

Interface

const CPU_8088    =  0;
      CPU_80186   =  1;
      CPU_80286   =  2;
      CPU_80386   =  3;
      CPU_80486   =  4;
      CPU_UNKNOWN = -1;

{ The cpu variable is initialised to the cpu type }
var cpu : integer;

{ Isa8088 returns true only if cpu is an 8088 or 8086 }
function Isa8088 : boolean;

{ Isa80186 returns true if cpu is an 80186 or higher }
function Isa80186 : boolean;

{ Isa80286 returns true if cpu is an 80286 or higher }
function Isa80286 : boolean;

{ Isa80386 returns true if cpu is an 80386 or higher }
function Isa80386 : boolean;

{ Isa80486 returns true if cpu is an 80486 or higher }
function Isa80486 : boolean;




Implementation

Uses Dos;

var OldIntr6Handler : procedure;
      valid_op_code : boolean;

procedure Intr6Handler;interrupt;
begin
  valid_op_code := false;

  { Stoopid TP7 won't let me modify IP directly }
  asm
    add word ptr ss:[bp + 18], 3
  end;
end;

function Isa8088 : boolean;
var sp1, sp2 : word;
begin
  asm
    mov sp1, sp
    push sp
    pop sp2
  end;
  if sp1 <> sp2 then
    Isa8088 := true
  else
    Isa8088 := false;
end;

function Isa80186 : boolean;
begin
  if Isa8088 then
    Isa80186 := false
  else
    begin
      valid_op_code := true;
      GetIntVec(6, @OldIntr6Handler);
      SetIntVec(6, Addr(Intr6Handler));
      inline($C1/$E2/$05);  { shl dx, 5 }
      SetIntVec(6, @OldIntr6Handler);
      Isa80186 := valid_op_code;
    end;
end;

function Isa80286 : boolean;
begin
  if Isa8088 then
    Isa80286 := false
  else
    begin
      valid_op_code := true;
      GetIntVec(6, @OldIntr6Handler);
      SetIntVec(6, Addr(Intr6Handler));
      inline($0F/$01/$E2);  { smsw dx }
      SetIntVec(6, @OldIntr6Handler);
      Isa80286 := valid_op_code;
    end;
end;

function Isa80386 : boolean;
begin
  if Isa8088 then
    Isa80386 := false
  else
    begin
      valid_op_code := true;
      GetIntVec(6, @OldIntr6Handler);
      SetIntVec(6, Addr(Intr6Handler));
      inline($0F/$20/$C2);  { mov edx, cr0 }
      SetIntVec(6, @OldIntr6Handler);
      Isa80386 := valid_op_code;
    end;
end;

function Isa80486 : boolean;
begin
  if Isa8088 then
    Isa80486 := false
  else
    begin
      valid_op_code := true;
      GetIntVec(6, @OldIntr6Handler);
      SetIntVec(6, Addr(Intr6Handler));
      inline($0F/$C1/$D2);  { xadd dx, dx }
      SetIntVec(6, @OldIntr6Handler);
      Isa80486 := valid_op_code;
    end;
end;


begin
  if Isa8088 then
    cpu := CPU_8088
  else if Isa80486 then
    cpu := CPU_80486
  else if Isa80386 then
    cpu := CPU_80386
  else if Isa80286 then
    cpu := CPU_80286
  else if Isa80186 then
    cpu := CPU_80186
  else
    cpu := CPU_UNKNOWN;
end.