How to store charset data if is char more than 8px W 16px H?

for 16-32 high chars the format is
char 0: 0,1,2,3,4.......29,31
char 1: 0,1,2,3,4.......29,31

You can not have more than 8 pixels of data per line of a char, any locations beyond the 8th will always be empty.

So, finally - is 9 and larger width by any way useful?
No matter of hard work.
'Cause using 8x32 is useless while we are talking about non-interlace mode. Using 16x32 characters could be very useful...

Miro

I'm sure tokra could speak more definitively on whether 9 pixel characters with full control over the 9th pixel is possible. For a 16 pixel wide 256-character font, you could disable horizontal intercharacter spacing and define your character set such that the left half of a character is in the first 256 slots in character definition RAM, and the right half in the second 256 slots. Then when you write to screen RAM, write the same byte twice. For example, for character 0, write two 0s. But in attribute RAM, clear bit 7 for the left character, and set bit 7 for the right character to select the second half of character definition RAM.

Even widths in between 8 and 16 should be possible too if you don't mind wasting some bits in your character definitions. So for instance, if you want 14 pixel wide characters, I think you'd put 7 in R22 3-0, and 6 in R22 7-4. I might be wrong on the exact numbers but it should work something like that.

One thing to keep in mind with intercharacter spacing off, you'll have to build spacing into your character definitions if you want it. So a 16 pixel wide font would really only be 15 useable pixels.

It's not. Semi-graphics mode is as close as you get to any control over the intercharacter gap. You can set a total width of up to and including 16 pixels if you want, but you can only ever define the first 8.
Yes you could do that and you would effectively have a 40column display with 16pixel wide chars with full control of the definitions. This is essentially what is done in the vertical scroller at the end of RFO VDC.
If you only needed 128 chars, you could use a single font and with the top $80 chars for the other half. Because you can reverse with attributes on the VDC, you could still do a full CBM font with reverse that way.
No, a total width of less than 8 pixels is invalid and you just get black. i.e. you are restricted to multiples of 8 pixels.
Yes. It might look a little tight and you might want to 'waste' 2 pixels to get a more readable font, a bit like a 2x2 multicolour font on the VIC.