On 07-02-2013, at 4:30 AM, "Juan Vuletich (mail lists)" <juanlists at jvuletich.org> wrote:
> The Windows VM supports both big endian and little endian Display. This was done by Andreas and is supported in Cuis, see #setDisplayDepth. This essentially came from Squeak, so it's likely that Squeak can do the same.

Yeah, that's pretty much what I remember. IIRC it sorta worked on RISC OS but something important didn't do the right thing… maybe display update areas were wrong? I'll have to try it out again sometime. To make life that *extra* bit fun, the RISC OS pixel format is quite different to that used by Windows, even when endian-ness is corrected for. So even when using 32bpp in Squeak and on screen I still have to swap bits around.

> 
> On the Windows machines I tried, I could not see relevant performance improvements, and I guess this is because of Intel's instruction set and Andreas' performance tricks. But supporting this could be useful for RISC OS, right?

The good news for the future - such as it might be for RISC OS, hardly a major player these days - is that the PI has some honkin' great big GPU stuff hidden in there. And the OS source is open so potentially the assorted screen driving code could be mangled to accept Squeak-format pixels and tweak them in the GPU magic sauce.

> 
> I remember in the old days of OS/2 Squeak, I added inline asssembly to use the fast intel asm op for byte reversing a 32 bit word…

Always fun to do devious stuff like that, isn't it :-)


tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Useful Latin Phrases:- Canis meus id comedit = My dog ate it.