Try to find manual for the laptop, it should tell you what kind of memory can be used, and how can it be combined. Without knowing the laptop model, it's pretty impossible to say what's compatible and what's not.
There are even 128MB SO-DIMMs, but I'm guessing there isn't many laptops supporting these.

It is an Siemens 1998 PG720p ( I not II )
- the manual says 32 and 32 MB is max but it is very confusing manual.

I bought extra 1pc 32MB and would like to combine it with 8MB but I have to try to find out. Hope RAM does not break or such different Voltage or so...

The bought 32 MB Smart RAM is made in USA the 8 MB one is made in Germany ?

The only thing that could break stuff is an incorrect pinout or an incorrect voltage.

Which SO-DIMM is in the laptop now? Looking up that module's exact specs should tell you the type of module and the voltage. Then you can check whether other SO-DIMMs correspond to that. Best way to look it up is to look at the codes on a specific chip. That last bit of the Siemens module code looks like a chip code: HYM324025GD-60

HY suggests Hyundai, you can find the key to the code here:
http://www.idhw.com/textual/guide/noin_ram_chip_hyundai.html

HY=vendor, Hyundai
M=unclear
Blank=5.0V
32=32M, 4k refresh
40=x4
2=4 banks
5=EDO
GD=die revision (not Ichon or Cheong-ju apparently)
-60=60ns

So this looks like a bog standard 5V 72p EDO SO-DIMM. The good news is that you're not going to fry this, it's possible that the laptop wants 3.3V RAM, in which case 5V probably won't work, but it certainly won't break anything to try it.

Here the original setup is 16MBx2pcs = Total 32MB....
Original is Siemens HYM324025GD-60 RAM EDO 72-pin 16MB
- Looks like there are 4 slots to use ?
- Mainboard AMD K6 233mhz "little foot" socket 7.
- Windows 98
- So this computer needs 5V edo ram ? What comb manufacturers made these and are they common to find on ebay.com ?

Picture of memories and slots
http://i162.photobucket.com/albums/t278/12311 … zpsd23onmbs.jpg

Tried to order USA made Smart Cisco 32mb memory comb but I don't know if laptop recognizes it ?
- The USA made Smart Cisco is +2mm longer in height and it is a tight fit also.
SM5CSC8M32003 ( MFG year 1999 )
SM32L4E88-60-SP9D
4LC8M8C2 on top of chips
PFCI00102322 Assembled in USA
p664072fxbj6gax
32mb 72p 60ns 4c 8x8 4k edo so-dimm
[*] Where can I put this Smart Cisco 32mb memory comb if it is not combatible with this Siemens laptop ? What laptops does it fit ?
[*] Is this 5V or 3.3V or are there more variations on EDO SO-DIMMS ?

The Windows 98 still says the total is 32MB now. Is it possible that 16+16+32=64MB is installed but the mainboard/bios/windows can only visibly show 32MB even when there are actually 64MB or more in use ?
SLOT0: 16MB Siemens
SLOT1: 16MB Siemens
SLOT2: --EMPTY-- Smart Cisco did not fit in here-.
SLOT3: 32MB Smart Cisco USA
=> Total 64MB

user33331 wrote:

Here the original setup is 16MBx2pcs = Total 32MB....
Original is Siemens HYM324025GD-60 RAM EDO 72-pin 16MB

That's the text on the sticker, which sounds legit - but double-check whether the chips themselves (those black things) show the same code.

- Looks like there are 4 slots to use ?

That's quite an unusual motherboard...

- Mainboard AMD K6 233mhz "little foot" socket 7.
- Windows 98
- So this computer needs 5V edo ram ? What comb manufacturers made these and are they common to find on ebay.com ?

Nothing unusual about 5V EDO, the vast majority of EDO for desktop and laptop computers was 5V. So the answer is: pretty much all manufacturers. As for are they common... haven't looked for any for a very long time. Have a look and see.

Picture of memories and slots http://i162.photobucket.com/albums/t278/12311 … zpsd23onmbs.jpg […]
Show full quote

Picture of memories and slots
http://i162.photobucket.com/albums/t278/12311 … zpsd23onmbs.jpg

Tried to order USA made Smart Cisco 32mb memory comb but I don't know if laptop recognizes it ?
- The USA made Smart Cisco is +2mm longer in height and it is a tight fit also.
SM5CSC8M32003 ( MFG year 1999 )
SM32L4E88-60-SP9D
4LC8M8C2 on top of chips
PFCI00102322 Assembled in USA
p664072fxbj6gax
32mb 72p 60ns 4c 8x8 4k edo so-dimm
[*] Where can I put this Smart Cisco 32mb memory comb if it is not combatible with this Siemens laptop ? What laptops does it fit ?
[*] Is this 5V or 3.3V or are there more variations on EDO SO-DIMMS ?

I'm sure theoretically other variations exist, but basically it's either 5V or 3.3V.

Run that chip code through IDHW:
SM32L4E88-60-SP9D
SM = Silicon Magic
32 = RAM type ?
L = Low Voltage 3.3V
4 = 4Mbit
E = die revision E
88 = ?
-60 = 60ns
SP9D = serialization code

So this is 3.3V EDO. Probably won't work (i.e. it would be fried by 5V).

In general I'd recommend sticking to SO-DIMMs for regular PCs rather than for network equipment (such as this Cisco stuff), more chance of 5V parts.

The Windows 98 still says the total is 32MB now. Is it possible that 16+16+32=64MB is installed but the mainboard/bios/windows c […]
Show full quote

The Windows 98 still says the total is 32MB now. Is it possible that 16+16+32=64MB is installed but the mainboard/bios/windows can only visibly show 32MB even when there are actually 64MB or more in use ?
SLOT0: 16MB Siemens
SLOT1: 16MB Siemens
SLOT2: --EMPTY-- Smart Cisco did not fit in here-.
SLOT3: 32MB Smart Cisco USA
=> Total 64MB

Is that the BIOS giving that list? Or just you? Either way, the way to test an unknown module is to first try to boot with only the new module in slot 0. Only if that works, try combinations with other modules.

OK. Thanks. I bought the wrong ram(3.3V).
I'll go back to ebay.com and seek for real "5V EDO 72-pin SO-DIMM".
- Where do these CISCO RAMs come from ? Ebay is sometimes full of them. What is the source of CISCO RAMs ?

user33331 wrote:

OK. Thanks. I bought the wrong ram(3.3V).
I'll go back to ebay.com and seek for real "5V EDO 72-pin SO-DIMM".
- Where do these CISCO RAMs come from ? Ebay is sometimes full of them. What is the source of CISCO RAMs ?

FRU for Cisco devices, probably (old) routers or switches. Googling "cisco edo 3.3v 72p" gives results for old CPU cards for Catalyst 6400 switches. Not sure if that's 100% correct, but that's the sort of ball park.

Regular PCs with EDO have been EOL for years now, but core network hardware has much longer life cycles. Probably these Cisco beasts just went EOS/EOL, so there are still significant stocks of these SO-DIMMs that are now being dumped all over the place.

Hello ( 4 slots )
Do I need all 4pcs of memory combs to be exactly identical ?
- Can a 2(pair) be from one manufacturer and 2(pair) from other manufacturer ?
Or must I buy all Hyundai 5V (16mb+16mb)+(16mb+16mb) to get 64mb ?

Manufacturer is not particularly relevant, but total size and chip structure should be the same per pair. Put simply: the SIMMs must be the same size and have the same number of chips. The two pairs do not need to be the same.