For those who are planning to use AMD K6-II CPU rated higher than 350MHz for your system running Windows 95B or 95C,  you need  amdk6upd.exe . 

This one can be used for P-90 Y complex.
 

	SW SETTING SW1 CORE/BUS FREQUENCY RATIO P1 P2 OFF OFF 1.5 x OFF ON 2.0 x ON ON 2.5 x ON OFF 3.0 x
	P1 connected to BF1 ( Pin X34 ) P2 connected to BF0 ( Pin Y33 )

I got this unit very cheep planing to use it for 8640. Back in home, pulled off the outer case of Server 320, set a K6-233 onto the interposer securely and attempted to place it onto the socket on the planar....A huge heat sink sit in front of CPU sockets BLOCKED the interposer. 
For P-90 Ycomplex, you have to rearrange fins of LT11084 heatsink so that you can set the interposer on the socket properly.

This unit looks like with an  Evergreen's CPU adapter introduced in Tam's page. 

When I got Server 500, This one could have it's home for a while. Yes, just for a while.
I bent two of the pins when I pushed it onto the socket while I tested CPUs including MMX 233.   One of the bent pin was finally torn off when I tried to straighten it. Grrr.....  Broken Arrow, that's it.

 Compatibility ( physically fits or not )

PC Server 320  8640-Mxx	No
Type 4 Y ( P-90 complex )	Yes ( rewrk needed )
PC750 6885/5886

 
 

		SW1:P1 OFF OFF ON ON SW1:P2 OFF ON OFF ON RATIO 3.5/1.5 3 2 2.5 CPU  P55C, M2, K6  ( P54C, K5 ) RATIO 3  3 2 2 CPU 6X86, 6X86L CLK VCC Socket 5  5V Socket 7 3.3V SW1: P4 ON OFF CORE VCC 3.3V 3.1V 2.8V 2.5V SW1: P5 P6 P7 P8 CPU P54C K6 *1 P55C M2  *1 Some of K6-233 are rated 2.2V  VCC

 Compatibility ( physically fits or not )

PC Server 320  8640-Mxx	Yes for main socket,   Not good for 2nd socket
Type 4 Y ( P-90 complex )	Rework needed.   Not recomendable.
PC750 6885/5886	Yes

Newer Version now listed in Powerleap website.
Looks like PL-ProMMX Plus Ver 4.0.  No capaciors at the front edge but the switch block locates at CPU side. 
I don't have this model.  It may fit to PCServer 320 both for main and 2nd socket,  P-90 complex, PC750  and other
clone like IBM PCs.
 

JP2, Jumper blocks for Core Vcc setting, and  a can type capacitor locates in front of Pin 1.  Overhang of  PCB for these parts hits the Voltage regulator in front of 2nd CPU socket of  8640/MCA planar. 
NO, it does not fit to 8640-MYR.  It doesn't fit to the 2nd CPU socket but DOES fit to the 1st socket. 
It can be used for PC750 too. 

 Compatibility ( physically fits or not )

PC Server 320  8640-Mxx	Yes for main socket,   Not good for 2nd socket
Type 4 Y ( P-90 complex )	Rework needed.   Not recomendable.
PC750 6885/5886	Yes

 

		Front View  Jumper Block for Core voltage  settings and a capacitor in front of  the PCB may interferes with a  heatsink of voltage regulator on a  8640-Mxx  2nd CPU socket and on  a Type 4 Y P-90  complex  .
		Bottom View ( left )    Silk printted as      "PL-ProMMX Plus        REV 2.1 " Rear View  ( right )

 JP1 Settings: Clock Multiplier

	P55C, K6, K6-2, 6x86L, 6X86MX, MII( Dual Volt ), C6, P54C( Single Volt )								6X86 *2
CLKMUL	6 x  *1	5.5 x	5 x	4.5 x	4 x	3.5 x	3 x	2.5 x	2 x
Pin 1-2	Closed	Open	Open	Closed	Closed	Open	Open	Closed	Closed
Pin 3-4	Open	Open	Closed	Closed	Open	Open	Closed	Closed	Open
Pin 5-6	Open	Closed	Closed	Closed	Closed	Open	Open	Open	Open

 *1:  6x setting is not listed in the installation guide.
 *2:  For 6x86( Single-Voltage ) and 6X86L ( Dual Voltage )
 

JP2 Settings: CPU Voltage and Overheating Protection

Core Voltage	3.5V	3.3V	3.2V	2.9V	2.8V	2.2V	1.8V
CPU Type	C6 WinChip	P54C	K6-233 *1	K6-200 6x86MX	P55C 6X86L	K6-266/300 K6-2	K6-3  *2
JP2: Pins 1-2	Closed	Closed	Open	Closed	Open	Open	Closed
JP2: Pins 3-4	Closed	Open	Open	Open	Open	Closed	Closed
JP2: Pins 5-6	Closed	Closed	Closed	Open	Open	Open	Open
JP2: Pins 7-8	Closed	Closed	Closed	Closed	Closed	OPen	Open
JP2: Pins 9-10	Closed	Closed	Closed	Closed	Closed	Closed	Open

*1  Check carefully actual voltage printed on the Chip.  
      Some are rated 3.2V and the others are rated 2.2V. 


*2  K6-3 is listed in  the guide book.  I myself have not yet tested K6-3 with this interposer.
 

Pins 11-12:   CPU Overheating Protection)

JP2: Pins 11-12	Overheating Protection
Closed	Enabled
Open	Disabled

Attention : Current product of this model is sold as  PL-ProMMX Plus.  You 'd better check how it looks like if you are planning to use it for Type 4 Y P-90 complex.  Older version with exactly the same name  may not fit to Type-4 P-90 complex. The Latest model is sold with a heat sick/fan combo which is different from the one pictured below.

Upgrade for Pentium 75-200 to Intel MMX233 and K6-2/400-450.
Wide variation for CORE VCC.  Covers most of  intel,  AMD ( except K6-III ), IBM/Cyrix and IDT CPUs.
This one can be used for PC Server 320 8640 ( both for 1st and 2nd socket),  Y complex and  PC750  6885/6886 .  No capacitor nor jumper block locates in front of Pin 1( front-end of the PCB ),  thus the interposer will not meddle with a heat sink of  a 320 planar or Y complex. 
 

 Compatibility ( physically fits or not )

PC Server 320  8640-Mxx	Yes for both main and 2nd socket
Type 4 Y ( P-90 complex )	Yes
PC750 6885/5886	Yes

SW1 Setting
SW1: Pins 1,2 & 3 for Clock Multiplier

	P55C, K6, K6-2, 6X86MX, MII( Dual Volt ), C6, WinChip2, P54C( Single Volt )								6X86 *1
CLKMUL	6 x	5.5 x	5 x	4.5 x	4 x	3.5 x	3 x	2.5 x	2 x
Pin 1	ON	OFF	OFF	ON	ON	OFF	OFF	ON	ON
Pin 2	OFF	OFF	ON	ON	OFF	OFF	ON	ON	OFF
Pin 2	OFF	ON	ON	ON	ON	OFF	OFF	OFF	OFF

SW1:  Pins 4, 5, 6, 7 & 8 ( Core Voltage )

Core Voltage	3.5V	3.3V	3.2V	2.9V	2.8V	2.4V	2.2V
CPU Type	C6 WinChip	P54C 6X86	K6-233 *	K6-200 6x86MX MII	P55C 6X86L	K6-2/450	K6-266 K6-300 K6-2
SW1: Pin 4	ON	ON	OFF	ON	OFF	OFF	OFF
SW1: Pin 5	ON	OFF	OFF	OFF	OFF	OFF	ON
SW1: Pin 6	ON	ON	ON	OFF	OFF	ON	OFF
SW1: Pin 7	ON	ON	ON	ON	ON	OFF	OFF
SW1: Pin 8	OFF	OFF	OFF	OFF	OFF	OFF	OFF

* Check carefully actual voltage printed on the CPU label. 
  ( there are two types in K6-233, different core Vcc ) 

* You can set Core Voltage to another value not listed in above diagram. 
   From 1.30 V to 2.00V by 0.05V stepping and from 2.0V to 3.5V  by  0.1V stepping.

SW1: Pin 10 ( CPU Overheating Protection )

SW1: Pin10	Overheating Protection
ON	Enabled
OFF	Disabled

SW1:Pin 9
No comment for Pin 9 in the associated Manual .  But there is a instruction for this pin sw in Installation Guide PDF for PL-K6-III.  Don't know if Pin 9 actually works for this model or not.  At least,  in all sample diagrams for CPU setting show this pin in OFF position.

   FROM PL-K6-III PDF 
   SW1: Pin 9 (Pin AL-1 Compatibility)
   Pin 9 of SW1 lets you enable/disable the pin signal for split-voltage detection. This
   function provides compatibility for certain HP Vectra and Biostar systems that
   check the signal.
   For split-voltage CPUs, certain HP Vectra (VL100 and VL5/133 Series 5 DT)
   systems and certain Biostar motherboards (8500TUD and M5ALA) check for the
   presence of a signal from pin AL-1. Unfortunately, these systems use the AL-1 pin
   signal differently: the signal must be disabled in order for the HP Vectra systems to
   function properly, while the Biostar motherboards need to detect the signal in
   order to boot.
   If your HP Vectra or Biostar system does not run properly with the PL-K6-III
   installed, try using pin 9 of the SW1 DIP switch to turn the AL-1 pin signal on/off.
   Pin 9 is set to ON by default--this setting allows Biostar systems to detect the pin
   signal and boot. For HP Vectra systems, changing the switch setting to OFF will
   disable the signal and allow the system to function. 
   Most systems (including most HP Vectra systems and
   Biostar motherboards) will be unaffected by the pin AL-1
   setting.

 

 Multipling Pins

		Pin	Active Level	Synchlonous/ Asynhclonous	Internal Register
P54C	BF0	Y33	HIGH	Synchlonous/RESET	Pull-up
	BF1	X34	HIGH	Synchlonous/RESET	Pull-up
P55C	BF0	Y33	N/A	Synchlonous/RESET	Pull-down
	BF1	X34	N/A	Synchlonous/RESET	Pull-up

 BUS Frequency Selection for P54C 

BF1	BF0	BUS/Core Ratio	Core Frequency ( MHz )	External BUS  Frequency ( MHz )
0	1	1/3	200/180/150	66/60/50
0	0	2/5	166/150/125	66/60/50
1	0	1/2	133/120/100	66/60/50
1	1	2/3  *1	100/90/75	66/60/50
0	0	1/4  *2	266/240/200 *2	66/60/50 *2

 *1  Default BUS/Core ratio is 1/2 for P54C.
 *2  4x mode was not officially announced by Intel but it is told that some Pentiums with
      marking of SXxxx and SYxxx have this special Core/BUS ratio. 

  Early Pentiums ( P-90 & P-75)  do not have BF1
 

 BUS Frequency Selection For P55C

BF1	BF0	BUS/Core Ratio	Max BUS/Core   Frequency ( MHz )	Min BUS/Core  Frequency ( MHz )
0	1	1/3	66/200	33/100
0	0	2/5	66/166	33/83
1	0	1/2  ( *1, *2 )	N/A ( 2)	N/A (2)
1	1	2/7	66/233	33/177

 NOTES:
 1. This is the default bus to core ratio for the Pentium® processor with MMX™ technology. If the BF pins are 
     left f loating, the processor will be configured for the 1/2 bus to core frequency ratio.
 2. Currently, there are no products that support these bus fractions.
 

Intel CPU is used for this accelerator.  But Y complex can't boot with it.  Works fine for 6886 planar so far..