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PPro on a BX?

Discussion in 'Overclocking' started by P2B, Oct 7, 2004.

  1. P2B

    P2B Guest

    I intercepted some old systems on their way to the dumpster today, and
    grabbed a couple of interesting items I hadn't seen before: Asus C-P6S1
    Socket-8 to Slot-1 adapters, complete with PPro 200Mhz/1MB L2 CPUs. They
    were on Asus 440FX boards, KN97-X IIRC.

    I tried them on a few Asus 440BX boards (with FSB and multiplier jumpers
    set appropriately), and they POST but freeze after announcing the BIOS
    version - no CPU identification is displayed. My POST diagnostic card
    says x0D, which is undocumented but IME means "BIOS does not support
    CPU" - so I tried a rom.by patched BIOS. It got a little further -
    correctly displays the CPU type (but not speed) and POST code x0E before

    The 440BX datasheet does not *explicitly* state PPro CPUs are supported,
    but quotes like "A Pentium® Pro processor-based system with the Intel®
    440BX AGPset supports 4 GB of addressable memory space and 64 KB + 3 of
    addressable I/O space" strongly suggests they are.

    Anyone know if this is a chipset issue, or strictly BIOS? I'd like to
    use the processors, but the only spare motherboards available have 440BX


    P2B, Oct 7, 2004
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  2. I'm not sure which of the 440BX data sheets you've got but

    Intel® 440BX AGPset:
    82443BX Host Bridge/Controller
    April 1998

    makes it pretty clear that BX works with the Pentium Pro although it
    doesn't support all it's capabilities (such as PCI ECC and > 4 gig memory).

    You'd think it would work because a P-II is basically a repackaged (slot
    cart), fewer features (removed the 'mission critical' ones), less expensive
    (slower cache) Pentium Pro.

    Because of that I'd say it's a BIOS problem.
    David Maynard, Oct 7, 2004
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  3. P2B

    P2B Guest

    Yup :)
    Must be - since it POSTs :-?

    Googling for PPro & 440BX doesn't yield much. I don't know of any BX
    boards with 'official' support for PPro.

    Has anyone got it to work?
    P2B, Oct 7, 2004
  4. Neither do I and it doesn't surprise me because, as much as that spec sheet
    says about Pentium Pro, why would anyone want to? The Pro isn't a 100Mhz
    FSB processor and BX was specifically made for the 100Mhz FSB P-IIs.

    Nearest thing I found to a Pro on a P-II motherboard, besides the Asus that
    slot adapter was made for, is this one


    (note that he mentions only a particular rev BIOS works)

    And then this, sort of, 'PCChips, like, dual socket' (ooo that hurt.. but
    then it felt good too <g>) supermicro board with a socket 8 and Slot-1
    both. (That'll confuse the heck out of someone with a PPGA celeron)


    You hack around in the BIOS. Can't you 'steal' the CPU codes from one of
    those and patch it onto the one you want?

    Although, I beginning to suspect that it isn't just processor
    identification, or even microcode, and that the Pro needs the registers set
    up a bit differently that the P-II.
    David Maynard, Oct 7, 2004
  5. Well, I found something else that doesn't necessarily resolve anything but
    is, nonetheless, rather interesting. This guy's Dell BX motherboard


    reported his new P-III 700 on a slotket as a "Pentium Pro 500."

    Apparently there was something in that BIOS that had, even if nothing else,
    at least the string "Pentium Pro" in it.

    Maybe you should be looking for the oldest BIOS you can find for those
    boards in the hopes they might have 'Pro' remnants left.
    David Maynard, Oct 7, 2004
  6. Wow, didn't know such adapters exist...
    Is it possible the PPro might have some erratas which make it necessary
    to have PCB/bios workarounds? I haven't looked at the spec update, but
    such errors are not uncommon. And the workarounds might not be present
    on the P2B.
    And I hope the bios doesn't use some mmx code to initialize it...
    Also, google shows some people got it to work in P2L97 boards, but not
    with all bios versions (only the oldest one worked?), which probably
    indicates it is a bios problem on the p2b too.

    Roland Scheidegger, Oct 7, 2004
  7. P2B

    Spajky Guest

    hey P2B, you experiment so much, that one day you´ll come out with a
    success of running even IBM G4 or AMD chip on BX ... :))))) ...
    Spajky, Oct 7, 2004
  8. P2B

    Hamman Guest

    I wouldnt piss about with them too boards too much, BX chipsets can take
    upto 1GHz P3's which is somewhat faster than a PPro

    Hamman, Oct 7, 2004
  9. P2B

    P2B Guest

    BX can do better than that :) The board was running a Tualatin P3-S @
    1575Mhz (150Mhz FSB) before I pulled it to try the PPro.

    I "piss about" for interest's sake. I've explored the high end of BX
    capabilities, now curious about the low end...


    P2B, Oct 8, 2004
  10. P2B

    P2B Guest

    LX chipset... getting warmer :)

    Perhaps not... the 'particular rev' is the very first release for that
    board, and he says later versions didn't work :-(

    FX chipset - same as the Asus board the adapter was made for.

    Sure I can... but it isn't a microcode problem - POST doesn't get
    anywhere near that far,

    My thinking too - I hoped Bios Patcher would help. Quoting from the manual:

    => Patcher can add support of CPU:

    - AMD K6/K6-2/K6-III/K6-2+/K6-III+
    - Intel Pentium Pro/Pentium II/Pentium III/Celeron
    - AMD K7/K75/Athlon/Duron/Athlon 4/Athlon MP/Athlon XP (tested!)
    - Intel Pentium 4/Celeron-478 (tested!)

    "Support" means not only names of CPUs (which shows with kernel name and
    can be change) but correct init of L2-cache, FSB, Multiplyer, support of
    different steppings. There are many thing that patcher makes, and all of
    them that the manufacturer didn't make for correct support of CPU.

    The patched BIOS is able to identify the CPU, but goes no further :-(
    Good suggestion.

    The oldest BX BIOS I have archived is 1006 for a P2B-DS (09/15/98), but
    the results are identical - freezes at the same point, patched or not :-(

    Anyone got a truly *ancient* Asus BX BIOS they'd be willing to send me?
    P2B, Oct 8, 2004
  11. P2B

    P2B Guest

    New one on me too - piqued my interest :)

    Very little to them - a Socket 8, 6 filter capacitors and a dozen or so
    surface mount caps, nothing else.
    It's definitely starting to look that way - further research shows the
    initial KN97-X BIOS didn't support PPro either, Asus released one to go
    with the adapters.

    Do you have any ancient Asus BX BIOSes? The oldest I have is 1006
    (which, surprisingly, boots a P3-S but gets no further along with the PPro).

    P2B, Oct 8, 2004
  12. P2B

    P2B Guest


    I suppose if I learn to write BIOS from scratch, anything is possible...

    P2B, Oct 8, 2004
  13. Yeah. That was part of the reason for mentioning it: Not 'strictly' FX.
    Yes, I know: 'old'.
    Right. But both on the same board from a different manufacturer suggested
    there's nothing particularly 'special' in the hardware for one vs the other
    and that the Asus adapter shouldn't need an 'Asus' board. Not 'proof', but
    a suggestion.

    That does seem like it should work, unless it didn't go in right for some

    Ya know, after all that talking I did about being hardware similar, I
    suppose it's possible there's some 'magic' pin/power/signal somewhere, like
    FC-PGA vs PPGA, that just didn't get put on later boards. I wonder if
    scouring old Intel Slot-1 docs would uncover some rev level change in the
    slot=1 wiring from model #1 to the later ones.

    Come to think of it, are your BX boards able to supply the Pro's 3.3v Vcore?
    David Maynard, Oct 8, 2004
  14. P2B

    ~misfit~ Guest

    I agree. I have a Tui Celeron running at 1.6Ghz on a BX here.
    Me too. These slockets you've found fascinate me. I've always liked the P
    Pro, especially the 1MB, 200Mhz version. The first x86 CPU with on-die,
    full-speed ECC cache wasn't it?

    Interesting project, keep us informed if you feel so inclined. I'd like to
    know how you go.
    ~misfit~, Oct 8, 2004
  15. P2B

    Rob Stow Guest

    I built and maintained a bunch of PPro workstations
    way back in those olde days of yore. Bleeding edge
    x86 workstations by the standards of those days :)

    My recollection is that the PPro L2 cache ran at half speed.

    My recollection is also that the PPro L2 was not "on-die".
    The cpu core and the L2 were separate chips that were
    put side by side into a single cpu package.

    I would be happy to concede that my ancient
    memories are wrong if someone could provide a link
    to a reputable source.
    Rob Stow, Oct 8, 2004
  16. Unfortunately, no. I doubt though it would help, since the p2b boards
    are quite a bit newer than the p2L97 boards it seems unlikely asus used
    the same code which permits the oldest p2l97 bios to run the ppro in the
    initial p2b bios.

    Roland Scheidegger, Oct 8, 2004
  17. P2B

    P2B Guest

    Not sure if the L2 is on-die, but it definitely runs at full bus speed:

    P2B, Oct 8, 2004
  18. P2B

    P2B Guest

    Sigh... I expect you are correct (pessimist!), but I (optimistically)
    think it's worth a try *if* I can find a very early BX bios.

    P2B, Oct 8, 2004
  19. P2B

    P2B Guest

    Agreed - all available information so far points back to BIOS as the
    issue :-(
    Not a problem, they support 1.3v -> 3.5v
    P2B, Oct 8, 2004
  20. Nope, full speed. That's why it was so expen$ive and Intel preferred to
    use half-speed SRAM chips for the PII. Everything on the same die was
    first to be found with the 2nd gen Mobile PIIs (.25µ, 256K L2) of which
    the well-known Mendocino Celerons apparently were a scaled-down version
    (same CPUID at least).
    AFAIK that's correct.

    I've always wanted to have one of these BIG chips (just for looks),
    maybe I'll run across one cheap some day.


    PS: My P2B-D now finally runs 2 667@500Es - that's what I call a longish
    upgrade. Since I was unable to find any S370-DLs, I had to have my 6905
    Masters modified, then the 2nd proc took a while to arrive, but now it's
    running fine. I had to increase the VCore from 1.30 to 1.35 V, otherwise
    performance was too low with both procs loaded. (I guess ye olde cA2
    CuMine is pretty much at its limits when run at 500 MHz with 1.30 V
    core.) Hey, it's still plenty cool enough... :D
    Stephan Grossklass, Oct 8, 2004
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