Old style screen modes on RPCEmu

Hi all sorry if this has been covered before but

Is RPCEMu (RISC OS 5) emulating old screen modes? A real Iyonix will default to a 256 colour mode equivalent but RPCEmu seems to emulate the real mode. For example MODE 1 is MODE 1 on RPCEmu not MODE 13 (as you would get if you went into MODE 1 on the Iyo).

thanks

Richard.

Surely you’ve just answered your own question?

The reason low-colour modes don’t work on the Iyonix is because the nVidia graphics cards don’t support them. Support for the modes was never removed from the OS, all that happens is that the OS realises the hardware can’t cope with it so it picks a 256 colour mode as an alternative. So for hardware which does support low colour modes (RiscPC, BeagleBoard, etc.) everything works as normal and no mode substitution is performed.

Thanks for clearing that up Jeffrey, I was aware of the Iyonix issue, but because (until recently) RISC OS 5 never ran on anything other than the Iyonix I was assuming RPCEmu with RISC OS 5 was emulating an Iyonix. Hence my reasoning that I was expecting it to emulate the mode substitution.

Incidentally, Jeffrey, O fount of all knowledge: now that we have new ARM hardware (Beagleboard, RPi etc.) is that mode substituion a thing of the past? A pain it was, trying to run BBC Basic programs and getting shades of red instead of colours….

Not all hardware supports all colour depths, so it’ll depend on what you’re using. BB supports all colour depths, RPi currently only supports 8bpp & 32bpp (16bpp is a possibility in future), Pandaboard I think supports 8bpp and above (or is it 4bpp and above?).