P Type 4 Complex
Rf90954a.exe Reference disk for Type 4 Complexes
Rd9095a.exe Common Diagnostics for all 859x / 959x Systems

Type 4 Common Devices

"P" / Upgrade Pentium 60 MHz  52G9362
Memory supported, cache, features 
Support for Convenience Partition on >3.94GB Drives
BIOS releases
    Flash BIOS 05 from BIOS 03 or less
    BIOS Level Revison Features
FDIV Replacement
Diagnostic LEDs
Intel Pentium Overdrive 133MHz (POD133/120)
496 vs. 497 Cache Controller

"P" / Upgrade Pentium 60 MHz  52G9362 
CR1,2 Diagnostics LEDs
J3 Serial Diagnostics Link to operator panel
J5 Serial Link
JMP5 Flash ROM Bank Switch
OS1 60 MHz oscillator. CPU Bus clock.
U3   10G3407 Flash BIOS, Odd ?
U5   10G3372 Flash BIOS Even ?
U10,12,15,16,18  82491-60Cache
U11   Socket 4 (5v) for Pentium 60
U13   87X0079
U17   A82496-60 Cache controller
U23   10G3441  SynchroStream Controller 
U24   50G8192 Unknown DMA Controller?
U25   Linear Tech LT1085CT Voltage Reg

U23 10G3441 Synchrostream Controller- may be yellow (early) or blue (fixed). I have a ceramic version and Peter has seen a metal capped one. Version trivia

P Complex Back

OS2 40 MHz MCA Bus Clock

Intel Pentium Overdrive 133MHz (POD133/120)
From Terminaut
   I dug through craploads of old Intel documents today, and found my notes from Intel (circa '95) for the Pentium Overdrive 133MHz (POD133/120) processor.
   Written in plain ingles, the Intel doc says: "will not support the 82496 Cache Controller and 82491 Cache SRAM chip set"
   Additionally, the documentation states that the POD133 is designed to support _PCI_ chipsets.
Some other notes:
 - IU, IV, and IBT plus have been removed
 - branch trace pins (BT[3:0]) have been removed (no execution tracing)
 - breakpoint pins (BP[3:0]) have been redefined such that each assertion of one of these pins indicates that 1 to N BP matches occurred, where N =core/bus frequency ratio
- STI/CLI (restore/clear interrupts) are each 2 clocks shorter

496 vs. 497 Cache Controller 

 From Dr. Jim Shorney 
   Overdrive processors are not compatible with the '496 cache controller on the P60/66 complexes.  However...  I swapped out the '496 cache controller on mine for a borrowed '497 (well heatsinked)  and was able to boot DOS with a POD 133 on my P60 (overclocked to 66).  It wasn't entirely stable, and would not boot OS/2 Warp 4.0 or NT 4.0.  The Powerleap PL54C interposer was still dead in this configuration.  There may yet be hope, I haven't tried the Powerleap with anything other than an Intel 166 yet, and I may also downclock the complex back to 60 MHz and see what happens.  There may yet be hope... 
      The '497 reportedly has a 3.3v core, but it seemed to run stable and reliable for several hours with the stock P60 CPU in my system in place of the 5v '496.   I briefly looked over the docs this afternoon (712 pages, wow...). Seems the '497 is still a 5v part, it is the I/O buffers that connect to the CPU that are 3.3v.  This probably explains in part why the chip doesn't self-destruct in the '496 socket.  It also seems to invalidate the need for an  interposer, since the P60/66 I/O is 5v anyway and the buffers would have to run at 5v to interface at all with the CPU.  This brings up the question of noise immunity, though - will circuits designed to run at 3.3v logic levels be more or less sensitive to noise or poor signal quality when run at 5v?  Inquiring minds want to know. 

From Tony Ingenoso
    I suspect noise is going to be less of a problem at higher voltages Jim.  In theory, the voltage range for correct operation would be wider(particularly for CMOS).  The only reason I ever saw (other than laptop applications) for the drive to lower voltages was to limit heat as the gate counts and frequencies went up.  CMOS parts like high voltages -- you can crank clock speeds faster with higher voltages(the standard overclockers trick).  Discrete type CMOS parts can often be run as high as 20V and work fine.  The downside is that its power characteristics start approaching those of TTL at the higher speeds (and heat goes up).  If the only nominally 3.3V sections of the cache controller are the line drivers/buffers, there's probably not going to be enough stuff getting overvoltaged to make any significant difference in the power draw. 

9595 Server 95 (AKA "Server 95 560") 
9595-0PT - P60, 16/256MB (ECC), 1GB SCSI-2 F/W, 2.88
9595-0PTF - As above - Canadian French
9595-0PV - P60, 16/256MB (ECC),2GB SCSI-2 F/W, 2.88
9595 Server 95 Array Models (called 95A) 
9595-3PG - P60, 16/256MB (ECC), 3 x 540MB SCSI-2 F/W, 2.88
9595-3PT - P60, 16/256MB (ECC), 3 x 1GB SCSI-2 F/W, 2.88,

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