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.
"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
used)
C4D1 (.1uf) -decoupling/bypass capacitor
R3F2 (10k ohm) -MS to V+.
That should do it!
References:
Intel NV430VX Motherboard Technical Product Specification (August
1996)
Intel 430VXPCIset Design Guide (June 1997)
PS:
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
Anonymous"