Trouble pointing to copy of character set on 130XE

[Tyrop]

I am dabbling with learning machine language on a 130XE. I'm booting with Spartados 3.2g. I wrote a program to copy the character set from ROM starting at $E000, to RAM starting at $2600 (just an arbitrary location). I copied all 1024 bytes. But when I put $26 into CHBAS (decimal 756) or poke 756,38 (decimal for $26), I get an unexpected result: all upper case disappears and all lower case appears as upper case. I was expecting there to be no change because I was poking 756 with the location of the start of the character set. It should be exaclty the same as if I left 756 pointing to $E000, shouldn't it? I even manually compared the entire 1K block starting at $2600 with the 1k block starting at $E000. My copy program worked, i.e., the blocks were identical. What am I doing wrong?

[kenfused]

I am dabbling with learning machine language on a 130XE. I'm booting with Spartados 3.2g. I wrote a program to copy the character set from ROM starting at $E000, to RAM starting at $2600 (just an arbitrary location). I copied all 1024 bytes. But when I put $26 into CHBAS (decimal 756) or poke 756,38 (decimal for $26), I get an unexpected result: all upper case disappears and all lower case appears as upper case. I was expecting there to be no change because I was poking 756 with the location of the start of the character set. It should be exaclty the same as if I left 756 pointing to $E000, shouldn't it? I even manually compared the entire 1K block starting at $2600 with the 1k block starting at $E000. My copy program worked, i.e., the blocks were identical. What am I doing wrong?

The character set has to be at an address on a 1K boundary IIRC (except graphics 1&2 which I think it can be 512 byyte boundary).

So going to $2400 or $2800 should work.

 

 

--ken

[Tyrop]

The character set has to be at an address on a 1K boundary IIRC (except graphics 1&2 which I think it can be 512 byyte boundary).

So going to $2400 or $2800 should work.

 

 

--ken

 

Wow that did it, thanks! I knew it was something simple, and now that you mention it, I remember reading that it had to be on a 1k boundary.