VBXE Fonts

[+Stephen]

I'm using TBXL and SDX as my environment.  I have loaded S_VBXE.SYS (far as I know it is the newest version).  I have loaded a 2kB font at location $8000 which is on a 2kB boundary.  According to the documentation, poking $2F4 with $80 shows the font (128 characters and the rest in inverse).   Poking with $81 shows all 256 characters.  So far, so good.  However, poking with $82 in order to prevent the ATASCII - ASCII translation does not work.  The font I am loading is from https://int10h.org/oldschool-pc-fonts/fontlist/font?ibm_cga

 

The font should have $00 as blank, $01 as smiley face, etc.

 

The attached video shows that it does not.  CHR$(00) prints ASCII 64 (the @), CHR$(01) prints ASCII 65 (the A).  The video also shows what happens when poking values to register $2F4.  I start at $80, then show $81, $82, $83, $84, $85.

 

Am I doing something wrong, or is there a bug in the S_VBXE.SYS driver / documentation regarding 2kB fonts?

 

Thanks for any help.

[Rybags]

I've not really played with 80-col on VBXE much.

 

But if your characters displayed are not as expected, it could be to do with the relative mapping of screen codes to ATASCII.

Also - the S: driver - is it's character base being copied from $2F4 assumed to be an absolute Atari Ram address or an address within VBXE's VRAM?  As usually those two are different.

[drac030]

10 hours ago, Stephen said:

So far, so good.  However, poking with $82 in order to prevent the ATASCII - ASCII translation does not work.

Indeed, that function was busted. Try this:

 

svbxe109.arc

 

There is yet some bad interaction between this driver and the CON.SYS driver regarding the local color. The symptom is that after POKE $2F4,$81 (or $83) any new characters are not visible. I am currently not sure how to solve that, but there is a workaround: after POKE'ing as above, just do CLS or, if clearing the screen is not desirable, do POKE 711,PEEK(709) (i.e. copy the global foreground color to the local foreground color).

[+Stephen]

Thanks for the quick update.  Attached is a screenshot of using $83 ($82 produces similar output, but with the bottom half displayed in inverse).  Only characters 0 through $20 are being displayed, then they mirror.

[drac030]

Oups, a too-quick update apparently. What about now?

 

 

svbxe109b.arc

[+Stephen]

1 hour ago, drac030 said:

Oups, a too-quick update apparently. What about now?

 

Perfect!  Thanks so much for the quick fix.