onboard memory, turn it off and still no joy

[drwho]

i installed 2X128 PC100 and been reading on the forum about how the second slot will only show half the amount of the ram because the onboard uses the second slot. so, after reading i decided to turn the onboard memory off and hopefully it will allow the full amount of ram to show up. well, i believe i turned it off correctly using editor and changing the default from 80 to 81 @ 2B

i hope this is the correct location

00 1 2 3 4 5 6 7 8 9 a b c d e f
10
20 80
30


sorry if my pic is not up to specs...just want to make sure.

so, where the 80 is located...changing it to 81 will turn onboard memory off. my memory still showed up will the onboard memory off but still half the amount of ram only.

did i do it wrong or it just does not work for me.

IBM 600 300mhz , sorry don't have the serial #, i have the latest bios updated.

any thoughts on why, thanks

[pkiff]

WARNING: This post contains information about modifying your CMOS/BIOS. Incorrect modifications of your CMOS can result in permanent damage to your Thinkpad. I cannot guarantee the validity of the information in this post. Use this information at your own risk!

This is starting to get dangerous. Modifying your CMOS is something that should be done with great care as it is possible to permanently damage your machine if it is done incorrectly. You should never change a byte in your CMOS where you "hope this is the correct location".

The byte you have identified in your diagram does not contain any bits that disable/enable onboard memory as far as I know. The byte you have identified is byte 20. Byte 20 is the one you can change to disable the L2 cache. This does not disable your onboard memory, it only disables the cache on that memory. I don't know what will happen if you change that byte to "80" as you have done. Normally, the value of this byte is either "00" or "02", depending on unknown factors. I would recommend changing this byte back to whatever your original value was. The only reason to start modifying this byte is if you have installed a PIII CPU and you want to disable the L2 cache so that you no longer get Error 127 during boot-up. I don't think that your plain vanilla Thinkpad 600 can accept a PIII module, so there should be no reason for you to change this byte in CMOS.

For reference purposes, and for future readers of this thread, Byte 20 is located here (marked by **):

Code: Select all

    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F 
00 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
10 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
20 ** XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX 
30 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
40 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
50 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
60 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
70 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX

I am not sure which byte in the CMOS controls onboard memory, however, according to some sources, it is a bit within Byte 2B. See, for example, the "Mod" section of Katch's "Mod the Pad" site.

I cannot recommend disabling your memory this way as I personally have never done it, and I am not about to play with my CMOS to test it. However, IF you are adventurous and confident about editing your CMOS, then byte 2B is not located where you have identified. It is located here (marked by **):

Code: Select all

    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F 
00 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
10 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
20 XX XX XX XX XX XX XX XX XX XX XX ** XX XX XX XX 
30 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
40 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
50 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
60 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
70 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX

According to Katch (and others), the value of Byte 2B should be "80" by default. If you change this from "80" to "81" then this is supposed to disable your onboard memory.

If you attempt this modification, please let us know if it is successful or not, and please also include your full model number.

Good luck! and Be Careful!! CMOS edits should not be undertaken lightly!

Phil.

[drwho]

sorry, i placed the " 80 " in the wrong place ....its located in the second diagram of yours. i changed the 2B to disable the onboard memory hoping it would allow me to use the full ram amount, instead of half.

i changed it, still would not read full amount of 128mb, only half, i read that because its a pc100 it will only show half...that's why someone suggested on a post to disable the onboard lose 32 instead of 64 from my 128 chip.

[pkiff]

Oh, I see. Yes, when you post in the forum it will remove all extra spaces, so your diagram wouldn't include the spacing you indicated -- that's why I put mine inside

Code: Select all

 brackets.

Can you confirm that your onboard memory was indeed disabled when you did this (even though it didn't help solve your problem with your 128MB PC100 sticks)?

[drwho]

ok, it might sound stupid...to confirm, i assume you change it to " 81 " at 2B and see if it boots reading the correct amount only like 1 stick of 128 with the onboard disable would read 128. if that's what you mean, then yes....but i had the other 128 stick in the second slot and it only gave me 192

any thoughts then...i might be doing something wrong... i don't think so.

i changed it to 81 and " refreshed " it and saved and reboot.

[warwound]

Have you tried swapping the two memory modules to see if there's any difference?

warwound.

[drwho]

hi, yes....i tried changing the ram and still the same