Here are your clues!

1) (probabally) came out of a Gateway 2000
2) Has PCI, no VLB
3) Phoenix Bios, 4.04c
4) PS2 Mouse and KBoard
5) It can take the Intel P24D, or SX or DX
6) Has Intel PCI chipset, weird #: 82425EX.
7) 3.3 or 5v operation
8) mfg. on 2/17/95
9) id# of BAT41P3E E29439897
10) mfg. by SCI

Main problem I have is I want to know the jumper settings for certain, want
to know if there's any possible way to set for 40Mhz (since it only has
25/33 printed on it, and if anyone else knows any other info about it
(speed, problems, etc.)

thanks 1e6!

(p.s. I can get more MB's like this for $50 or so)

(normally I refrain from such a obtuse subject, but...)

I may have found a problem in using the DX4-100 with certain motherboards!

(BTW, I have one sold by Gateway, produced by SCI, and designed by Anigma. 
It is an 'Aries 2'? with a number 'MBDPCI003AAWW'

If you're one of the people who run Norton SI and get 131 or so instead of
200 with an AMD, READ ON and please help me confirm!

I got my 486 motherboard with no processor.  I plugged in an AMD DX4-100
processor, and found to my suprise that the BIOS reports that the processor
was a DX2-66.  After trying EVERY jumper combination possible I was still
unable to make it ever say DX4-100.  But it seemed much faster than the
DX2-66's at work (which don't have PCI!), so I assumed everything was ok.

Well, I compared my computer's performance to others on the net with the
DOOM benchmark (I'm trying to maximize performance for DOOM almost
exclusively!) and found that my computer was almost exactly the same speed
as DX2-66's with PCI graphics cards!

At this point I became extremely suspicious that there was another problem;
so I began to pursue the following leads:

1) find a newer BIOS
2) re-check the jumper settings
3) find out how the AMD does its clock multiplying settings

results:
1) I have Phoenix 4.04c.  Gateway claims that I should have 4.04.07.  They
don't have it.  Neither does 'Microfirmware', their BIOS distributor.
2) Gateway walked me through.  The correct settings were already there.
3) Got the AMD spec sheets via fax.  Learned that one pin, (can't remember
which number right now...) if floating or high will make the processor run
at 3x, otherwise at 2x.  I used my meter to see if any of my jumpers went
to that pin; none did.  This worried me at the time but I assumed that the
jumper went through some kind of buffering circuitry.

FINALLY I learned who made the motherboard, ANIGMA.  Gateway didn't have
their phone number, and it wasn't in the FAQ.  SO I looked in the Thomas
Register and finally found it.  Phone rang.  Get one of those 'dial the
extension now or press 0 for operator'.  Pressed 0.  Got music.  Got the
same 'dial the extension now or press 0 for operator' again.  Pressed 0. 
etc.  FINALLY someone answered.

I asked for tech support, she said they didn't have any and no engineers
could be bothered because they were too busy.  I begged to talk with some
kind hearted techie who might be able to quickly resolve why my MB only
runs at 66 mhz.  She said that I had to call Gateway, they would not help
end users.  I begged again.  She said the same thing.  After 7 or so
beggings she finally for some reason asked me about my problem again.  And
by some freak chance an engineer walked by and she asked him the question.

the answer:  CAN'T USE THE AMD!!!

now before I get 20 return messages saying "you idiot, didn't you know you
should check to see if AMD works on your motherboard?" let me respond
thusly: Yes I know AMD has a list of MB's that work.  But (!!) I assumed
that if I couldn't use the AMD I would have gotten no bootup at all!

The reason I'm making such a big deal here is that from the recent postings
on Norton SI scores and some of the benchmark scores I've seen I now
believe that MANY people owning AMD DX4-100's are running at DX2-66 speed!!
 That they too made the incorrect assumption that if your processor boots,
you're in business.  You're NOT!

Please respond if anyone else has similar experiences!!!

-- 
mtm (say: Empty-M)
mtmr@walsh.dme.battelle.org

>Newsgroups: comp.sys.ibm.pc.hardware.misc 
>I may have found a problem in using the DX4-100 with certain motherboards!
>Please respond if anyone else has similar experiences!!!

The problem you are having is a very common problem with older 486 MB's that 
do not support the AM486/DX4 chips directly.  The reason for that is that AMD 
uses a different pin for clock multiplier than the Intel.  On the AMD it is 
the pin B13.  This pin (CLKMUL) when set to high or left floating makes the 
chip run at 3x speed.  When grounded it makes the chip run at 2x speed.

There are some solutions:

1) Replace the MB (yeah, I know you've already thought of that)
2) Run the chip as DX2/100 (I.E. change the bus speed to 50Mhz if your MB 
    supports this speed).  This will make a big performance increase of your 
    MB compared with the DX4/100 setup.  There might be some stability 
    problems though, system will fly playing Doom by might crash sometimes
    when you're in Windows.
3) One way street: clip off the famous pin B13, this will make it floating and 
    it will always run at 3x, if you make a mistake and clip a different pin 
    then... :))

If you need more details e-mail me directly.

Damian
(Been there)

>1) The 33Mhz oscillator is on the DX4-100 itself, not the Motherboard
>(T/F?)

The motherboard (usually) can run at a variety of speeds.  In the case of a 
DX-33, DX2-66 and DX4-100s, the MOTHERBOARD speed remains at 33MHz.  
Motherboard speeds can sometimes be changed via jumper settings, depending on 
the motherboard.  In the case of the DX2-66 and DX4-100 chips, these CPUs 
contain clock-doubling and clock-tripling circuits respectively.  That is, 
they both have 33MHz clock pulses being fed into them from the motherboard, 
but the 2-66 doubles the clock pulses it receives, meaning the CPU runs at 
66MHz.  The 4-100 triples it so internally it runs at 100MHz (actually it runs 
at 99MHz, but who's counting).  Even though the CPUs both run at higher 
speeds, it must be understood that the motherboard continues to run at 33MHz.  
The speed of the motherboard does NOT match the internal speed of the CPU.  

For the SX-33, DX-33, DX2-66 and DX4-100, your motherboard should be set to 
run at 33MHz.


>2) The DX4-100 runs at 33, 66 or 99Mhz based on jumper settings on the MB,
>which actually does nothing but short pins on the DX4-100 together and/or
>hold certain pins high/low (T/F?)

This is incorrect.  See my statement earlier about motherboard speeds and CPU 
speeds.  


>3) A DX2-80 or DX4-120 will work in any motherboard (assuming 3.3v
>available) so long as I correctly jumper the aforementioned pins.

The DX2-80 and DX4-120 are clock-doubled and clock-tripled 40MHz machines 
respectively.  That is, the motherboard runs at 40MHz, and the 2-80 doubles 
the incoming clock pulses, the 4-120 triples the incoming clock pulses.  Once 
again the speed that the CPU runs at differs from the speed of the 
motherboard.  I'm not sure of the voltages, can't help you there!

Yvette.

>-- 
>mtm (say: Empty-M)
>mtmr@walsh.dme.battelle.org

----------------------------------
Yvette Lian
yal@lingua.cltr.uq.oz.au
IRC nick: Maxine2
http://www.cltr.uq.oz.au:8000/~yal

-- MattWalsh - 09 Mar 2004