Questions regarding FBlit and workbench

[Bloodwych]

I've discovered how to get Fblit working with Scalos so I can add it to the ClassicWB setups where appropriate. In the past people complained they couldn't get Fblit to work with Scalos, and since they wanted big flashy high colour workbenches they decided to run without it (and the ClassicWB).

For those who don't know, Fblit hands blitter functions to the CPU which can allow important things such as saving CHIPRAM by forcing Newicons and certain graphical functions to use FAST. It can also speed things up (depending on your CPU).

Before adding Fblit to the ClassicWB, I need to know a few things:

1. Anyone have any compatibility issues with running Fblit? I've avoided adding any patches to the classicwb base install that cause any kind of compatibility issues in comparison to a default workbench. If compatibility issues are present, I may add it as an option during install along with a warning.

2. Does Fblit suffer any performance loss with a standard A1200 020 in comparison to using the standard blitter? Or do you really need an 030 and higher before off-loading blitter functions?

[ppill]

FBlit is a fine piece of software. It was one of those programs I simply had to have in my startup-sequence when I worked on my a1200 setup(AGA+68040/40) next to MCP. Speed, Chip memory conservation... you name it. It came with an array of parameters that could be used to make sure it didn't clash with other patches. When set up correctly there are no issues whatsoever. Patching is like a form of art . If any problems crop up just tell us what they are.
There are also other patches worth considering for inclusion:
Syspatch
FText
PatchControl

just to name a few.

[ppill]

Originally Posted by Bloodwych

2. Does Fblit suffer any performance loss with a standard A1200 020 in comparison to using the standard blitter? Or do you really need an 030 and higher before off-loading blitter functions?

I guess that with a stock a1200(020+CHIP+AGA) installing FBlit wouldn't make any sense assuming it would work(I think it needs FAST). But when some Fast ram is available the whole system picks up in speed even with the built-in CPU.

[Bloodwych]

Thanks, some useful info there.

I've noticed the memory saving function of Fblit seems to only work with newicon image data and not the regular icon data in Scalos. Do you know if that's the same on normal workbench systems?

For instance, on a 64 colour newicon system it offloads quite a bit to fastram.

However, on a 16 colour normal icon (WB 3.0-3.1) system nothing is offloaded to fastram.

[ppill]

I'm not an expert when it comes to system functions FBlit patches (or other for that matter )but I guess that NewIcons use a special technique(when the rtg option is used) to process the gfx data outside of Chip ram and only use it when they appear on the screen. Something the pre 3.5 workbench icon.library doesn't offer. But it's just a speculation.

Here's a quote from FBlit's guide:

Being able to use rastport/bitmaps outside Chip memory is not really of
any great benefit in itself, since usually a rastport's bitmap will
simply be the screen's bitmap on which the rastport appears, and
therefore must be in Chip memory. It became necessary as a result of the
next part of FBlit. When all bitmaps are allocated with planes in Fast
RAM, temporary bitmaps allocated for overlapped window regions will also
go in Fast RAM, so parts of rastports can end up outside Chip memory
under certain circumstances.

Having the OS able to use Fast RAM for non-displayable bitmaps is all
very nice, and maybe useful for programmers who know about it and want
to take advantage of it, but it makes no difference to existing
software.

[Bloodwych]

Thanks for your help. I'll have a play around and see what's worth using in my ClassicWB packages.