[SOLVED] HP Pavilion ZD8000 BIOS RAM Limit?

[DeathBringer]

Make full CPU-Z TXT Reports with and without moving range.

[LoneCrusader]

Make full CPU-Z TXT Reports with and without moving range.

Attached.
Note some programs under Windows 9x (including this older CPU-Z and DXDIAG) do not report more than 2048MB of total memory if it is present. CPU-Z gets the total count wrong but however does see later in the report that there are two 2048MB DIMM's.

[DeathBringer]

Analysing result of these files: your friend just replace one byte in Host Bridge's registers to change TOLUD (Top of Low Usable DRAM).
I've found an interesting code in BIOSCOD2.ROM

Code:

5D1     mov     al, es:[esi+9Ch]  ; 0x9C is offset of TOLUD
5D9     cmp     al, 0A0h
5DB     jbe     short 5E7h
5DD     mov     al, 0A0h          ; set TOLUD to 0xA0000000
5DF     mov     es:[esi+9Ch], al
5E7     ...

Official BIOS has two files: 3082F34.M22 & 3082F34.M24. I don't know which of them you laptop uses.
Make BIOS backup by Universal BIOS Backup ToolKit 2.0.

[LoneCrusader]

Analysing result of these files: your friend just replace one byte in Host Bridge's registers to change TOLUD (Top of Low Usable DRAM).
I've found an interesting code in BIOSCOD2.ROM

Code:

5D1 mov al, es:[esi+9Ch] ; 0x9C is offset of TOLUD
5D9 cmp al, 0A0h
5DB jbe short 5E7h
5DD mov al, 0A0h ; set TOLUD to 0xA0000000
5DF mov es:[esi+9Ch], al
5E7 ...

Official BIOS has two files: 3082F34.M22 & 3082F34.M24. I don't know which of them you laptop uses.
Make BIOS backup by Universal BIOS Backup ToolKit 2.0.

Interesting. BIOS backup file here. I'm pretty sure that the choice of which file to use depends on the onboard video (there are M22 and M24 references in the ATI INF file in the HP display driver package for this laptop) so in reality both probably need to be patched.

Which actually leads to another issue; can the module for the onboard video be updated/replaced? Dell apparently issued an update for this particular onboard video that no one else seems to have covered. And, I wondered if another video BIOS module might help the onboard video be more compatible with the last official 9x ATI driver which supports other X600 devices but not this exact model? This is of course a less important issue and I'll worry about it later once the memory issue is fixed.

[DeathBringer]

Your laptop uses M24 (ATI Mobility Radeon X600). Version of current VBIOS is 008.019M.044.003, date - 02/21/2005. So Dell BIOS (008.017M.192.060) isn't compatible.
Try to flash my mod.

[LoneCrusader]

Try to flash my mod.

Unfortunately it doesn't work. After flashing it tries to power up and gives two quick beeps then a pause and then one longer beep. No display is output and it repeatedly tries to access the DVDROM drive for whatever reason. I tried ejecting the tray and leaving it out for the heck of it but it doesn't help. After a few seconds of this it will power down and start over again in a continuous loop.

I thought I had bricked it... but removing 1 of the 2GB DIMMs will allow the system to boot again.

So, the system can use the RAM once it is booted as already proven, but it can't POST with it all present and enabled.
I would hazard a guess that something else needs to be patched as well as the points you already found?

What did you use to be able to extract the ROM's? I tried the Phoenix BIOS Editor and it will list them but I can't do anything with them or extract them.

Your laptop uses M24 (ATI Mobility Radeon X600). Version of current VBIOS is 008.019M.044.003, date - 02/21/2005. So Dell BIOS (008.017M.192.060) isn't compatible.

So the second VBIOS version field is what matters for compatibility?
I have tried to find another VBIOS update for this particular graphics chip but no luck besides the Dell one. Any chance one from a standard PCI-E version of an X600 card would work?

[DeathBringer]

I need new screenshots of Device Manager with my mod & one DIMM.
P.S. I think your BIOS has the latest compatible vBIOS.

[LoneCrusader]

I need new screenshots of Device Manager with my mod & one DIMM.

P.S. I think your BIOS has the latest compatible vBIOS.

A user on another forum reported being able to use the last official 9x driver from ATI with a Dell laptop that has a Mobility X600 chip but I haven't been able to reproduce this. This is the only reason I would be interested in changing it at all. The last 9x package supports X600 devices generally but not this specific model. I have a couple of other ideas to try but trying to change the VBIOS is a last resort.

[DeathBringer]

Well, try to flash my new mod and test with one & two DIMMs.
P.S. Only third screenshot with expanded node Memory is useful.

[LoneCrusader]

Well, try to flash my new mod and test with one & two DIMMs.
P.S. Only third screenshot with expanded node Memory is useful.

This one works with both DIMM's. A step in the right direction at least!
Apparently something depends on the RAM being limited during POST.




You didn't say what you were using to be able to extract the ROM's.
Could you attach the uncompressed BIOSCOD2.ROM?