This information is not clear to me, can you explain it further?
I found 2 locations in the“CPOSDATA.BIN” file for different versions (v3.05, v3.06 and v3.061000) and altered these versions but the updater refused to update the OS.
Where the numbers in hex or plain-text?
There might be a number of other places to change too. Maybe there is also a checksum that should be recalculated.
The version is most probably both hardcoded into the updater executable and checked by the on-calc updater as well.
I thought that the HW of CP300Plus and CP330 are identical. Is there any difference?
We don't really know. No one tried to compare them.
I know that it is possible to change the OS version for the fx9860G and fx9860GII. Maybe we can do the same for ClassPad? I’m trying to but with no success.
Unfortunately unlike fx and Prizm, little work is done on discovering ClassPad secrets. I remember one or two topics about that here a very long time ago (2003 or so). I, like you, have no information about it.
However, I remind you of the dangers of this and strongly recommend everyone not to try downgrading or anything. By trying this you can fully destroy your poor ClassPad (which previously only had touch screen problems).
As we know, the OS 3.0 update makes substantial changes to the ClassPad's bootloader (which I don't know whether it lives on the bios or the flash, or wherever else) This might be the case with any OS version so partially changing some part in the OS Update and flashing it can make harmful changes to the ClassPad...
Enough lecture...
Gonna hex-edit the files and look what's in them though; looks interesting.