```Contributor: HANS-CHRISTIAN FRICKE

{
From: h.fricke@laguna.han.de (Hans-Christian Fricke)

> Here's some info I've found regarding CPU Speed -- could someone who
> knows how to implement assembler in Pascal help me out by converting
> this into a procedure or function.  Thanks in advance!

Wuuuuuaaaa...... try this, it's a LITTLE bit better:

}
Unit TaktFreq;

{\$B-,I-,V-,E-,S-,N-,R-,O-,X-,A+}
{\$IFNDEF DEBUG}
{\$D-,L-}
{\$ENDIF}

{
This unit contains a handy gadget for determining the CPU speed.  It is
NOT coded for the Pentium family.
}

Interface

Const
Cpu8086  = 1;
Cpu80286 = 2;
Cpu80386 = 3;
Cpu80486 = 4;

Function WhatCPU : Word;
{
This function examines the CPU and returns a number corresponding to the
CPU type;  1 for 8086, 3 for 80386, etc.  This procedure came right out of
Neil Rubenking's Turbo Pascal 6.0 Techniques and Utilities (thanx Neil!).
}

Procedure CPUSpeed(Var MHz, KHz : Word);
{
This procedure is a ROUGH estimation of how fast the CPU is running in
MegaHertz.  It was adapted from a C program found in the Intel forum of
CIS written by Glenn Dill.  I had to do some finagling of the original
code because C allows for a 32-bit UNSIGNED integer, whereas Pascal allows
for a 32-bit SIGNED integer (the LongInt), therefore, I was forced to
reduce all calculations by 10 in order to get it to fit properly.
}

{ ************************************************************************** }

Implementation

Function WhatCPU; Assembler;
Asm  { Function WhatCPU }
MOV     DX,Cpu8086
PUSH    SP
POP     AX
CMP     SP,AX
JNE     @OUT
MOV     DX,Cpu80286
PUSHF
POP     AX
OR      AX,4000h
PUSH    AX
POPF
PUSHF
POP     AX
TEST    AX,4000h
JE      @OUT
MOV     DX,Cpu80386
DB 66h; MOV BX,SP       { MOV EBX,ESP }
DB 66h, 83h, 0E4h, 0FCh { AND ESP,FFFC }
DB 66h; PUSHF           { PUSHFD }
DB 66h; POP AX          { POP EAX }
DB 66h; MOV CX, AX      { MOV ECX,EAX }
DB 66h, 35h, 00h
DB 00h, 04h, 00         { XOR EAX,00040000 }
DB 66h; PUSH AX         { PUSH EAX }
DB 66h; POPF            { POPFD }
DB 66h; PUSHF           { PUSHFD }
DB 66h; POP AX          { POP EAX }
DB 66h, 25h,00h
DB 00h, 04h,00h         { AND EAX,00040000 }
DB 66h, 81h,0E1h,00h
DB 00h, 04h,00h         { AND ECX,00040000 }
DB 66h; CMP AX,CX       { CMP EAX,ECX }
JE @Not486
MOV DX, Cpu80486
@Not486:
DB 66h; PUSH CX         { PUSH ECX }
DB 66h; POPF            { POPFD }
DB 66h; MOV SP, BX      { MOV ESP,EBX }
@Out:
MOV AX, DX
End;        { Function WhatCPU }

Procedure CPUSpeed;
Const
Processor_cycles : Array [0..4] of Byte = (165, 165, 25, 103, 42);
{
Notice that here I have defined the 8086 as a Processor type of 0 vice
the returned value of 1 from WhatCPU.  Since the original code did not
distinguish between the 8086 and the 80186, I can get away with this.
}
Var
Ticks,
Cycles,
CPS       : LongInt;
Which_CPU : Word;

Function i86_to_i286 : Word; Assembler;
Asm  { Function i86_to_i286 }
CLI
MOV    CX,  1234
XOR    DX,  DX
XOR    AX,  AX
MOV    AL,  \$B8
OUT    \$43, AL
IN     AL,  \$61
OR     AL,  1
OUT    \$61, AL
XOR    AL,  AL
OUT    \$42, AL
OUT    \$42, AL
XOR    AX,  AX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IDIV   CX
IN     AL,  \$42
MOV    AH,  AL
IN     AL,  \$42
XCHG   AL,  AH
NEG    AX
STI
End;  { Function i86_to_i286 }

Function i386_to_i486 : Word; Assembler;
Asm  { Function i386_to_i486 }
CLI
MOV    AL,  \$B8
OUT    \$43, AL
IN     AL,  \$61
OR     AL,  1
OUT    \$61, AL
XOR    AL,  AL
OUT    \$42, AL
OUT    \$42, AL

DB 66H,\$B8,00h,00h,00h,80h;
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
DB 66H,0FH,\$BC,\$C8;         { BSF  ECX, EAX }
IN     AL,  42H
MOV    AH,  AL
IN     AL,  42H
XCHG   AL,  AH
NEG    AX
STI
End;  { Function i386_to_486 }

Begin  { Procedure CPUSpeed }
Which_CPU := WhatCPU;
If Which_cpu < 3 Then
Ticks := i86_to_i286
Else
Ticks := i386_to_i486;

Cycles := 20 * Processor_cycles[Which_CPU];
CPS := (Cycles * 119318) Div Ticks;
MHz := CPS Div 100000;
KHz := (CPS Mod 100000 + 500) Div 1000
End;  { Procedure CPUSpeed }

End.

```