I've found the insteresting code in
0B_8 module:
Code:
74CB pushad
74CD mov eax, 1
74D3 cpuid
74D5 and ax, 0FFFh
74D8 cmp ax, 0F30h
74DB jb 7517h
74DD cmp ax, 0F60h
74E0 jb 74F1h
74E2 mov dx, 88Ch
74E5 in eax, dx
74E7 test eax, 80000000h
74ED jz 7509h
74EF jmp 7517h
74F1 mov ecx, 1A1h
74F7 rdmsr
74F9 test eax, 40000h
74FF jz 7517h
7501 test eax, 20000h
7507 jnz 7517h
7509 push 1000h
750C push 6DAFh ; offset of "Alert! Incompatible processor detected."
750F call far ptr 0F000h:52DCh ; printing alert string.
7514 jmp 4DF7h ; go to halt
7517 popad
7519 retf
I've made one byte patch:
Try to flash
my mod.
After flashing install new CPU, then try enter in BIOS and do
Load Defaults.
Then boot in Windows, make & post a screenshot of
regedit with expanded key
HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0
Amazing! You're a miracle worker DeathBringer, it's working now. Seems to me like Dell had BIOS support for Cedar Mill all along but for whatever reason prevented those processors from booting. Here's the screenshot you asked for:
http://imgur.com/a/kcc6G
One more thing, do you know of any way to manipulate the memory's CAS latency via BIOS modding? I can adjust every memory timing except CL using a tool called Memset but thought it would be nice to get the most out of my RAM. I'd be shooting for CL3 at DDR2-533 which I'm 100% sure my RAM supports, as I've tested it in another PC.
Thanks again for the quick and painless mod!
Nice news!
Add "[Solved]" to this topic's header by editing first post.
And please post new topic in
Confirmed CPU Support Upgrades with attached BIOS mod.
Your BIOS hasn't microcode for this CPU, but Windows loads microcode itself.
P.S. CL manipulating isn't supported by this BIOS.
Will do. Shame about the CAS latency but that's Dell for you.
Hey fellow hackers and good afternoon. I need a little favor so to save research time, etc...
Trying to put a P4 550 HT in title topic motherboard but Dell has artificial block saying the processor is incompatible, at boot. It is 3.4 GHz and same exact chip as the one it came with other than that one being 2.8 GHz.
So, can you mod this for me to rid this limitation? Any other mods like FSB settings etc... would be cool too, but really need the limitation removed.
Thank you!
https://www.dell.com/support/home/us/en/...00/drivers
Direct link to the bios update I need modded:
https://downloads.dell.com/bios/DV051A04.EXE
Thank you so much Deathbringer, both for your original work and for deleting my original thread. (I am almost always better than that hah hah!)
When I have access to the machine in question later on, I will give it a try with lots of confidence and post back about results. Rock on \m/.
Very surprised. I flashed twice, both times saying successful. Tried clearing cmos after, holding in power with it unplugged for 30 seconds, all sorts of things like that. Error message of incompatible processor still remains with faster chip. Even set defaults in bios, no dice. No big deal!
Make current BIOS backup by
Universal BIOS Backup ToolKit 2.0
Tell
sSpec of your
P4 550 HT.
Can you make TXT-report of
CPU-Z on other system with this CPU?