"Y" / Upgrade Pentium 90/60
"Y" / Upgrade Pentium 90/60 MHz 06H3739 The vaunted P90 complex "Cubrun"
U23 10G3441 Bus Interface
Controller- may be yellow (early) or blue (fixed). I
have a ceramic version and Peter has seen a metal capped
U24 50G8192 [early]
or 8190587 [late]. The 8190587 is only seen on the "Y"
complex. Not sure if there are internal differences -OR-
it is just a part number format change.
Dealing with P90 complex with
no CPU and/or L2 cache controller:
S-Spec numbers for 90MHz Pentiums affected by FDIV-Bug
P54-90 [A80502-90]: Q0542, Q0543, Q0611, Q0612, Q0613, Q0628, SX679, SX874, SX885, SX909, SX921, SX922, SX923, SX942, SX943, SX944, SZ951
Look for an A82497-60 Cache controller. At this time, I'm unaware of any stepping issues...
NOTE: A82497-66 works just as well...
8/64MB Parity, 8/256MB ECC 72-pin SIMM, ECC or Parity 70ns Presence Detect
Cache: 8kb L1, 256kb write-through L2 cache (P60, P66, P90)
* 40 MB per second streaming data transfer.
* Error Checking and Correcting (ECC) memory controller
* 20 MHz DMA; 32 bit can directly address all memory, supports Subsystem Control Block.
* Faster bus arbitration (than Base 1) for busmaster performance.
* Enhanced Dual Path Memory
* Subsystem Control Block enabled
* Vital Product Data support.
* Synchronous Channel Check support
* Data bus parity support
* A logging facility is provided (for ECC or system errors)..
178 POST Error
Laust Brock-Nannestad cried:
I managed to get hold of one of the much sought after P90 complexes (FRU 06H7095), but when I put it in my 9595A (replacing a P66 complex), it gives me error 0001 7800 and halts.
God Emperor of Microchannel replies:
Laust does cartwheels and says:
Everything was fine. Then I put the
complex back in the 9595A and it booted, completing POST
for the first time. After reconfiguring, the machine now
boots like normal (and the 90MHz on the front looks
rather sweet ;-) Next is adding back the cards
(It's currently stripped down to just the XGA-2 and
processor complex), but it seems to be working OK.
Oh yeah, QCONFIG told me the old BIOS
revision level was 03.
06H3739 vs. 06H7095
There are two FRUs for the P90 complex-
If you go to the EPRM
Oliver Schweizer said
FYI: I reworked a P90 platform today with a wire (and two solderings) and stuffed in a P-200 Non-MMX. Worked fine so far. Didn't have an appropriate heatsink at hand, so I cannot say anything on the long-term stability and any nasty side-effects.
At the moment I'm soldering a DIP switch onto the P90 platform to set BF0/BF1 accordingly to whatever core/bus ratio is needed. Maybe I install an adjustable clock generator on that thing too ... but I lack the time a bit.
Something I found out during my experiments: a platform with an 80497-60 reacts rather funny with higher speed CPUs. I stuffed in an 80496-66 and it worked much better. Got some silly cache errors (0129 xxxx) with the 497 cache controller. And the output voltage on the CPU regulator dropped to 2.5 Volt from 3.3 ...
No explanation at hand for that strange behavior (yet).
P90 to 180 MHz W/O Soldering
CM-174 Universal Adjustable
Clock Multiplier Adapter Kit
PL-ProMMX Iinterposer from
Power Leap Units that Failed