jmarkwolf
Junior Member level 3
I'm able to generate custom fonts in the upper half of the CGRAM (character codes $80 thru $ff) of my Optrex DMF5001 just fine while in CGROM mode.
My object is to "re-claim" the font space taken up by the standard font foreign, and I understand that I have to re-write a portion of the standard font set to utilize the lower half of the character generator RAM, but I am unable to make it work properly.
My Mode_set command specifies CGRAM and EXOR modes, my Offset register set = 3, my cursor pointer is set to $1800, I've updated all the character code references in my code, and I'm reloading the entire 2Kbytes of CGRAM space with my new character font data to addr $1800 thru $1FFF. But it will not display any text at all.
As I said above, the whole process works for me if I set all my pointers and commands to use the upper half of the CGRAM space, but fails to work at all if I make what I think are the appropriate changes for utilizing the whole CGRAM space.
Can anyone advise?
My object is to "re-claim" the font space taken up by the standard font foreign, and I understand that I have to re-write a portion of the standard font set to utilize the lower half of the character generator RAM, but I am unable to make it work properly.
My Mode_set command specifies CGRAM and EXOR modes, my Offset register set = 3, my cursor pointer is set to $1800, I've updated all the character code references in my code, and I'm reloading the entire 2Kbytes of CGRAM space with my new character font data to addr $1800 thru $1FFF. But it will not display any text at all.
As I said above, the whole process works for me if I set all my pointers and commands to use the upper half of the CGRAM space, but fails to work at all if I make what I think are the appropriate changes for utilizing the whole CGRAM space.
Can anyone advise?