VOGONS


How do I flash VBIOS on an S3 card?

Topic actions

Reply 20 of 20, by RichB93

User metadata
Rank Member
Rank
Member
Nemo1985 wrote on 2020-09-08, 09:52:

Unlucky, according to my archive the 1.01.03 has the brightness bug (it means that the black color become grey and it's noticeable on lcds).
Also can you please explain to me how did you find the right values for the clock of memory and cores and translated them in hxd?
Thanks

Yeah, I didn't notice it until I did more exploration and used the 2.01.07 BIOS linked in another thread after transposing my values from the 1.01.03 BIOS I edited.

Thankfully the process was quite straightfoward I found.

To confirm that the clock locations were indeed at 0xC2 in the BIOS, I ran MCLK on my system prior to any modifications - this gave me the m/n/k values.
I then converted these to hex using the MCLKCONV program in this thread.
I searched these values in a dump of my BIOS and confirmed they were at the right location.
I used PowerStrip to easily set the value and test.
I then shut down to dos and used MCLK to retrieve the m/n/k values that PowerStrip had set.
Again I used MCLKCONV to get the hexadecimal values.
I modified the BIOS with the values from above.
I then repaired the checksum by creating a checksum in HxD of the BIOS (minus the last byte). This value was then subtracted from 100(h) (you can convert both values to decimal if you find it easier, and convert them back), and then this final value is the checksum.
Finally flashed the BIOS to my card using my TL866 programmer and confirmed it worked okay.