Vera and petscii

[unartic]

Hi!

If I store $41 to address $1B000 via the DATA_O ($9F23) port on the vera, I expect to see an A on the screen. I do however get the a spades-character (from playing cards).


Does anyone know why and how to fix this?

[JimmyDansbo]

PETSCII codes are not the same as VERA screen codes.

You can see a chart of the PETSCII codes here: https://www1.cx16.dk/cx16-petscii/ and a chart of the VERA screen codes here: https://www1.cx16.dk/veratext/

If you want to write directly to VRAM, you could consider making use VTUI Library which is found here: https://github.com/jimmydansbo/vtuilib
Among other things, it has functions that convert between PETSCII and screen codes.
https://github.com/jimmydansbo/vtuilib# ... me-pet2scr

[unartic]

Thanx. That was the information I was looking for. Converting myself will not be a problem

Maybe a follow up question: I want to write directly to vram because in the emulator it is much faster than chrout. I’m developing a text based program with lots of rewrites to the screen.

Can I assume the performance difference will be the same on the real hardware?

[JimmyDansbo]

Yes, the emulator performs very similar to hardware.