SpritesMind.Net

Hi,


I just wanted to know if it was possible to use the 32x VDP without going (or having) the crappy genesis re-mapping...

PowerOn 32X > INIT/VDP > Shutdown 32x (but keep VDP output) > Run genesis game.

I think they did re-mapping to avoid interrupts timing problems on 68K if the SH is reading the cartridge... Any inputs?

I'm asking that because (if it is possible), we could load a display engine in 32x RAM, run it... Then run standard genesis genesis game keeping the 32x active.
Who never dreamt about a faster Herzorg Zwei with 256c backgrounds?


Thx.

I think that if 32X is disabled, you just can't access his parts :-/

So, even if the sh2 started to run code, if i disable 32x, sh2 will stop?
So bad ...

Not tested on real hardware but i think it will operate like this.
I can actually test rom on real hardware if you need it

The 68000 mapping relies on ADEN. Reset, you've got the usual mapping, set, you've got the alternate mapping.
I don't know if, once set, it can be reset without problem ...

YEah, ADEN is the key... but it would be great if setting ADEN to 0 (after intializing SH2 and letting them running from their ram) don't stop them...

There is a small chance... I can't wait to see a confimation/disconfirmation of this.

You know, I have in mind a project that would run original genesis game code (aden = 0) with a little hack to set some display process to the 32x (in total transparency).

I have in mind a great game named Z*** T****** that wouldn't suffer from a bigger screen display
Or a easier one : H****** Z*** that wouldn't suffer from a 256 colors background

If you get what i mean... :'(

The Hardware Manual states that, once it (ADEN bit) has been set, further "change (is) not allowed".

The ADEN means ADaptator ENable bit. If set to 1, the 32X is enabled and you can use it. If you set it to 0 (and if it's allowed to do it), i'm afraid you just can't use anymore the 32X hardware...