Is M29F040B compatible with 39SF040?

[zanor]

39sf040

Trying to fix a laptop. Original BIOS chip is SST 39SF040 but I only got a ST M29F040B.
Is these chips compatible with each other? Or what make them different.

I have programmed the 29f040 chip with a eeprom/flash chip programmer but the laptop won't post. It does turn on and charge with the BIOS chip installed.

But is ST M29F040B 100% compatible with 39SF040?

 

[M!k]

chip bios 39sf040

There's no difference between the two types if you're just reading from the flash (assumed same or faster access time). But the problem is the write algorithm which the BIOS uses at startup to store some device infos. Take a look at the datasheet of the ST and SST flashs (different manufacturers!). They differ in sector size, manufacturer code, device code, algorithm etc...
If your BIOS can't handle this new type there seems to be no chance to get it running :-(


Mik

 

[zanor]

new bios 39sf040

There's no difference between the two types if you're just reading from the flash (assumed same or faster access time). But the problem is the write algorithm which the BIOS uses at startup to store some device infos. Take a look at the datasheet of the ST and SST flashs (different manufacturers!). They differ in sector size, manufacturer code, device code, algorithm etc...
If your BIOS can't handle this new type there seems to be no chance to get it running :-(


Mik

Did'nt know the BIOS was saving device info in the BIOS chip.. hmm.. I'll have to order a new chip then.. Hope that will help :roll:
Learning new thing's every day!