Keith, at 11:28 on Jul 31 1996, you wrote to Bill Grimsley...

BG> Pin 17 of the 5x86 is the CLKMUL (Clock Multiplier), and if left
BG> floating (or high), the chip runs as a doubler or tripler (not exactly
BG> clear from the AMD docs for the 5x86, but this depends on other
BG> jumpered inputs).  However, when physically pulled low, the CPU will
BG> run at 4x CLK, even on boards which don't support this chip or mode.

KR> i dont think that i have a problem getting it to quadruple, there is one 
KR> link on the mb which put in one position causes the 5x86 to give identical 
KR> performance to a dx4-100 (its doing it now to produce this).

What brand of board, type of chipset, and BIOS ?

KR> if i move it to the other position (it's function is not explained in the 
KR> mb manual) the whole thing collapses, and locks on boot. using a dx4-100 
KR> the same positions make it run at 66mhz and 100mhz respectively. the 
KR> problem is just that the rest of the board cant take the strain of the cpu 
KR> running at 133mhz.

I find that hard to believe (no offence), as the CPU is only running at 4X
internally.  As far as the rest of the machine is concerned, it's the same
33MHz that would be used for a DX or DX4 chip.

KR> ps. i tried another motherboard of identical model, jumpered as far as i
KR> could tell exactly the same. it still hung in exactly the same way with
KR> the chip set as a quad, but with it set as a tripler, it gave a landmark
KR> of 270 instead of 475 with my motherboard ??????

Did you try setting it up as both the Enhanced AMD DX2/66 or DX4/100 ? 
With the former, it should run as a quad if you pull pin 17 low, and with
the latter, a normal tripler (assuming that the board doesn't actually
support the 5x86, which it obviously doesn't).

BG> at just $60 ex tax for the chip, that makes them great value IMO.

KR> i'd agree that it is great value if i could just get the thing to run, i'd 
KR> buy a new motherboard for $120 that i know will work, but that would mean 
KR> getting a new video, and scsi board coz the mb is pci. ):

FWIW, I've had my fun with the 5x86, and have just bought a Triton II 430VX
motherboard and a Cyrix 6x86/100 CPU (which runs a treat at 120MHz) for a
total outlay of just $300 inc tax.  That's only $100 more than a 5x86 board
and CPU, yet the difference in speed is staggering.  QDI have just released
a similar board, which has inbuilt SCSI, so perhaps something like that
might be the way to go?  Model number is P51430VX-250, and the Award PCI
flash BIOS includes NCR 810 and Adaptec 7850 SCSI BIOS.  Sounds very
elegant to me.

Regards, Bill
@EOT:

--- MsgedSQ/2 3.50