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    {
    > I'm upgrading my CPU Detection code to handle pentium... It's mostly
    > inline assembler in a pascal shell...

     I got this program from the Borland BBS. The description says "Detect CPUs
     up to Pentium in your code".

    Here is the code I use, adapted from the Intel Pentium Processor User's
    Manual, Chapter 5.  It sets the Test8086 global variable, making the values
    of Test8086:

       0 = 8086
       1 = 80186/80286
       2 = 80386
       3 = 80386   (new)
       4 = 80486   (new)
       5 = Pentium (new)
       6 = ??

    Note that for Pentium and higher CPUs, the new CPUID instruction is used to
    retrieve the processor family number.  This code should work on post-Pentium
    (80686-class) CPUs and Pentium compatibles, and could return numbers > 5.
    }

     program CPUTest;

     begin
      if (Test8086 = 2) then         { RTL check stops at 2 = 386}
      asm
                 inc    Test8086     { 3 = 386, for consistency }
        { Do we have a 386 or a 486? }
        { Does pushf/popf preserve the Alignment Check bit? (386=no, 486=yes) }
                 mov    bx, sp       { save current stack pointer }
                 and    sp, not 3    { align stack to avoid AC fault }
        db $66;  pushf
        db $66;  pop    ax
        db $66;  mov    cx, ax
        db $66, $35; dd $40000       { xor AC bit in EFLAGS }
        db $66;  push   ax
        db $66;  popf
        db $66;  pushf
        db $66;  pop    ax
        db $66;  xor    ax, cx       { Is AC bit toggled? }
                 je @@1              { if not, we have a 386 }
                 and    sp, not 3    { align stack to avoid AC fault }
        db $66;  push   cx
        db $66;  popf                { restore original AC bit }
                 mov    sp, bx       { restore original stack pointer }
                 mov  Test8086, 4    { we know we have at least a 486 }

        { Do we have a 486 or a Pentium? }
        { Does pushf/popf preserve the CPUID bit? (486=no, P5=yes) }
        db $66;  mov    ax, cx       { get original EFLAGS}
        db $66, $35; dd $200000      { XOR id bit in flags}
        db $66;  push   ax
        db $66;  popf
        db $66;  pushf
        db $66;  pop    ax
        db $66;  xor    ax, cx      { Is CPUID bit toggled? }
                 je @@1             { if not, we have a 486 }
        db $66;  xor    ax, ax
        db $f,$a2                   { CPUID, AX = 0 (get CPUID caps) }
        db $66;  cmp    ax, 1
                 jl @@1             { if < 1, then exit }
        db $66;  xor    ax, ax
        db $66;  inc    ax
        db $f,$a2                   { CPUID, AX = 1 (get CPU info)   }
                 and    ax, $f00    { mask out all but family id }
                 shr    ax, 8
                 mov    Test8086, al      { Pentium family = 5 }
       @@1:
      end;

      writeln('Test8086: ',Test8086);
     end.

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