Pentium Interposers and Upgrades


Interposers
   Evergreen
   PowerLeap
     PL-OD54C
     PL-MMX v2.01V
     PL-ProMMX (SVRAM) v4.0
     PL-ProMMX Plus
     PL-ProMMX Plus v4.0
   Zerus P55C-K6-S1
   Madex Interposers

Upgrade Kits
   Kingston
     TurboChip 233
     TurboChip 400
   Evergreen Spectra 233/400
   Buffalo HP5-MMX300L

Clock and Multiplier Selection Pins (BF1 and BF0)
   Intel Pentium
   AMD K6

If you are planning to use AMD K6-2 CPU rated higher than 350 MHz for your system running Windows 95B or 95C you need amdk6upd.exe.

Content created by Sandy. Edited by Major Tom.


Interposers

Evergreen (Photo by MadMax)

Switch Settings

CLK
MUL
P55C, M2, K6
(DUAL VOLTAGE)
P54C, K5
(SINGLE VOLTAGE)
3.5 (1.5)
3
2.5
2
P1
OFF
OFF
ON
ON
P2
OFF
ON
ON
OFF
P3
OFF
OFF
OFF
OFF

CLK
VCC
P55C, M2, K6 6X86L
SOCKET 5 (5V)
P54C, K5, 6X86
SOCKET 7 (3.3V)
P4
ON
OFF

CORE
VCC
P54C, K5
6X86 3.3V
K6 3.1V
P55C, M2
6X86L 2.8V
M2 2.5V
P5
ON
OFF
OFF
OFF
P6
OFF
ON
OFF
OFF
P7
OFF
OFF
ON
OFF
P8
OFF
OFF
OFF
ON

DIP switch settings to run a 233MMX chip:

P1 P2 P3 P4 P5 P6 P7 P8
OFF OFF OFF ON OFF OFF ON OFF

PowerLeap

PL-OD54C

Upgrade for P75/90/100 systems to P133 to P200 (Non-MMX Upgrade).
Voltage regulator is not used. This interposer provides clock multiplying jumpers for BF1 which is omitted in P75/90 systems. Very simple and easy to use. Actually speaking you don't need this interposer for upgrading P75/90 to classic Pentium 133-200, if you don't care for soldering rework of a planar.
Check Peter's Blue Book page for the method.

This one can be used on the Type 4 P90 "Y" complex.

PL OD54C

Switch Settings
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 )

PL-MMX v2.01V

Upgrade for Pentium 75-200 to MMX Pentium, K6 and M2.
Available CORE VCC; 3.3V, 3.1V, 2.8V, 2.1V
Maximum CORE/BUS ratio is 3.5 x ( MMX 233 & K6-2 333 )

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 P90 "Y" complex, 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 (P90 complex) Yes (rework 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

PL-ProMMX (SVRAM) v4.0

Older version

It looks like PL-ProMMX Plus (below). Two capacitors are placed around Pin 1 (front edge) but the switch block is placed inside the Socket at CPU side like PL-MMX listed above.

Compatibility (physically fits or not)
PC Server 320 8640-Mxx Yes for main socket, Not good for 2nd socket
Type 4 Y ( P90 complex ) Rework needed. Not recomendable.
PC750 6885/5886 Yes

Newer Version (manual)

Looks like PL-ProMMX Plus v4.0. No capacitors 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, P90 complex, PC750 and other clone like IBM PCs.

PL-ProMMX Plus (older version)

Upgrade for Pentium 75-200 to Intel MMX233 and (up to) K6-2/366.
Covers Core Vcc from 1.6V to 3.5V with 0.1V stepping.

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 (P90 complex) Rework needed. Not recommendable.
PC750 6885/5886 Yes

Front View (right)

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 P90 complex.

Bottom View (left)

Silkscreened "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

PL-ProMMX Plus v4.0

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" P90 complex. Older version with exactly the same name may not fit to Type 4 P90 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" (P90 complex) Yes
PC750 6885/5886 Yes

Switch 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: Pin 10
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.

Pin 9: Pin AL-1 Compatibility
SW1: Pin 9
ON
Pin Connected
OFF
Pin Disconnected

Zerus P55C-K6-S1 (Photos by Jim Hall, Explanation by Jim)

"For those of you who haven't seen this upgrade, it consists of an interposer similar to the Madex, with a plug for a power tap used on 3 1/2" clone style floppy drives to handle the power requirements of the Intel (or any pin compatible) CPU. The cooling fan also draws its power from the same source."

Exactly the same product was also sold in Japan before. it was named as "Multimedia CPU Upgrade Kit". It was made of Taiwan and marked as "CE". I don't know this "CE" logo which can be seen many computer products manufactured in Taiwan.

#1 Close View
#2 Bottom View
#3 Over View on Type 4 "Y"

#4 Jumper Block
#5 Setting Instruction
#6 Proud 90MHz of Jim's 95

Specifications
Socket 5 or 7
Voltage Supplied: 2.2V, 2.8V, 2.9V, 3.2V
Current rate: 15A for P55C-K6-S
Connection: 320 pin SPGA

Multiplication Jumper Setting
JP1 JP2 JP3 Speed
OPEN 1-2 1-2 x 2.5
OPEN OPEN 1-2 x 3.0
OPEN OPEN OPEN x 3.5
1-2 1-2 OPEN x 4.0
1-2 1-2 1-2 x 4.5
1-2 OPEN 1-2 x 5.0
1-2 OPEN OPEN x 5.5
1-2 1-2 OPEN x 6.0
x 6.0 is not documented, but theoretically...

  

Vcore Voltage setting
JP5 JP4 Vcore
OPEN 1-2 2.2V
OPEN 2-3 2.8V
1-2 OPEN 2.9V
2-3 OPEN 3.3V
Combination of JP5/OPEN and JP4/1-2 listed topmost column is printed as 2.1V on the PCB but supplement sheet says it was changed to 2.2V on -S1.

3.3V single voltage for I/O and Core is not designated. Thus Jim set Core voltage to 3.2V and put his classic Pentium P166 with 3x speed jumper setting and set it on his Y complex. Y complex has 60 MHz OSC so his system actually run at 180 MHz.

Report to the news group from Jim Hall:
   "OK, ran a little windows program called CPU id, by Alexander Berezkin. It identifies the CPU as an Intel Pentium, brand name Genuine Intel.
Type ID = 0
Family ID = 5
Model ID = 2
Stepping ID = 12
Clock Frequency, Internal = 180 MHz"

Careful with that axe, Eugene. Connection pins for SPGA socket are shorter than the others.

Madex Interposers

Information about Madex Interposers for Socket 5 and 7 systems:
   English Page
   German Page
   Jumper Settings

Content created by Sandy. Edited by Major Tom.


Upgrade Kits

Kingston

TurboChip 233 (guide)

Kingston TurboChip 233 uses Intel MMX233 CPU.

Features:

  • Powerful Intel® MMX enhanced microprocessor running at
  • 233MHz processing speed.
  • 32KB Level One (L1) Cache
  • Onboard voltage regulator to interface with either 2.8V or 3.3V system motherboard automatically.
  • Supports multimedia extensions instructions
  • "Plug and Play" installation. No software drivers to install.

Unfortunately TurboChip 233 does not have CPU speed jumper and it will automatically set the clock multiplier to 3.5x. It is supposed that TurboChip 233 may not run on Y complex. Any experience?

TurboChip 200

TurboChip 200 uses AMD K6 200 MHz. Most possibly, It will be kicked out by system BIOS of Y complex.

TurboChip 400 (guide)

Turbochip 400 uses K6-II/400 CPU. Needless to say it's incompatible with Type 4 "Y" complex.

But it may run in PC Server 320/520 or PC750 6886.

Evergreen Spectra 233 (manufacturer)

Not sure which CPU this unit uses, Intel MMX233 or K6. Anyway "233" means it may not work on Y complex.

There were several models rated 300 MHz to 400 MHz using K6-II CPUs like Kingston TurboChip.

I'm not sure but it seems Spectra upgrades do not have clock multiplier jumpers and they automatically set it to Max rating provided with the CPU used.

Buffalo HP5-MMX300L

CPU accelerator by Buffalo. Mobile MMX300 assembled on a PCB for PGA Socket 5/7.

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


Clock and Multiplier Selection Pins (BF1 and BF0)

Intel Pentium (from Intel Documents)

Multipling Pins
CPU Signal Pin Active Level Synchronous/
Asynchronous
Internal Register
P54C
BF0
Y33
HIGH
Synchronous/RESET
Pull-up
BF1
X34
HIGH
Synchronous/RESET
Pull-up
P55C
BF0
Y33
N/A
Synchronous/RESET
Pull-down
BF1
X34
N/A
Synchronous/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 (P90 & P75) 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
1. This is the default bus to core ratio for the Pentium processor with MMX technology. If the BF pins are left floating, 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.

AMD K6 (from AMD K6 manual 21850.pdf)

BF[2:0] (Bus Frequency) - Inputs, Internal Pullups

Summary BF[2:0] determine the internal operating frequency of the processor. The frequency of the CLK input signal is multiplied internally by a ratio determined by the state of these signals as defined in the Table below. BF[2:0] have weak internal pullups and default to the 3.5 multiplier if left unconnected.

Processor-to-Bus Clock Ratios
BF[2:0]
State
Processor-Clock
to Bus-Clock Ratio
100b
2.5x
101b
3.0x
110b
2.0x or 6.0x*
111b
3.5x
000b
4.5x
001b
5.0x
010b
4.0x
011b
5.5x
* The ratio selected is dependent on the stepping of the Model 8. The 2.0x ratio is supported on the Model 8/[7:0], whereas the 6.0x ratio is supported on the Model 8/[F:8].

Sampled BF[2:0] are sampled during the falling transition of RESET. They must meet a minimum setup time of 1.0 ms and a minimum hold time of two clocks relative to the negation of RESET.


PS/55 Index