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 Almost Everything You Need to Know About Your Packard Bell Computer
Adding L2 Cache to a PB 680

I added this page page because I am always getting asked if it is possible to add L2 cache by mounting the appropriate L2 cache chips onto the motherboard.  I am glad to say YES it is possible.  However I have to remind you it should only be done by those that know what they are doing and keep in mind if not done correctly the motherboard could be damaged.

The average user can not add L2 Cache, only those that have some electrical engineering experience will be able to accomplish this.  I say this because I would not have a clue how to proceed adding L2 cache, even after reading the information on this page.

Below is the email I received from an individual that added 512 L2 cache to his PB 680 motherboard.  I would say that if it can be done it may be able to be done on other PB motherboards, unfortunately this is the only report I have received of a successful addition of  L2 cache to motherboards that do not have CELP sockets.

At this time I do not know of any companies that will provide this service.

"Ray have the steps necessary to add Pipe-lined Burst L2 cache to the PB680 (Orlando) motherboard.  The steps involve surface mounting two pipelined burst SRAM chips and a tag ram.  It is best performed if a local surface mount shop is available. The  addition will likely void any warranty.  I have added 512k bytes to a PB680 using Winbond SRAM.

First the disclaimers:
This was done for the challenge of it (I'm an electrical engineer).  These modifications will likely void warranties and it is possibly to damage the motherboard if not done carefully. I accept no responsibility or liability for these changes or their consequences. Much of the information I used for tracking down how to perform these modifications was greatly facilitated by your web site and as such I would like to give some information back. Keep in mind that by publishing this information, OEMs may be discouraged from publicizing certain technical materials in the future.

No BIOS changes are required for this. The BIOS will recognize the L2 cache
if installed correctly.  BIOS used: 1.00.12.DNOR

Parts - These are the parts that I have used and I know work. By all
indications other parts will likely work but I can't make any recommendations about them.

Chips needed:

Winbond W25P022AF-6 (2 pieces, 64k x 32bit 3.3v PBSRAM -6 nsec)
Winbond W24129AJ-12 (1 piece, 16k x 8bit 5v Tag RAM, 28 pin SOJ -12 nsec)
(note: according to information in the references 8.5 nsec or faster PBSRAM,
and 15nsec or faster Tag RAM should work for 66Mhz host bus frequencies)

Procedure (requires soldering very small pieces or surface mount work):

Move the following resistors which are located near the 82437VX chip:

R4B4 to R4B3
R4B6 to R4B5
(note these resistors provide the 512kbyte cache config selection, read on
power up)

Install the following:

Install the PBSRAM and tag RAM chips, the pads are the vacant pads near the
CPU and the orientation should be marked on the motherboard.

R1E4 (22 ohm) -clock feed, series termination
C1E6 (4.7pf to 22pf) -EMI reducing capacitor

R2D1 (10k ohm) -provides Enable #2 (CE2)
R2F1 (220 ohm) -provides /Enable #3 (/CE3)

R4D4 (0 ohm) -provides /OE for Tag RAM
R4D5 (0 ohm) -provides 5v for Tag RAM (note: R4D1 is used if 3.3v Tag RAM is
C4D1 (.1uf) -decoupling/bypass capacitor

R3F2 (10k ohm) -MS to V+.

That should do it!

Intel NV430VX Motherboard Technical Product Specification (August 1996)
Intel 430VXPCIset Design Guide (June 1997)

These chips where obtained from a distributor through our business and
unfortunately I cannot name the source for them. They are fairly common
however.  I have an extra set of the chips (2 x PBSRAM + Tag RAM) required for this  upgrade and would happily trade them for PowerLeap Pl-Pro/MMX adapter if you know someone who may be interested.

Have fun

Well there you go, that is all the information I have.  Use it how you want, but remember you take full responsibility for your actions, this information was provided to expand the volume of information about Packard Bell Computers.
I can not answer any specific questions as to how to do this; because I did not do this procedure.  You are on your own if you wish to try this as all I can supply is the information on this page.

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