> Hmm, have you considered rendering the screen from a text copy of the
> screen instead of scrolling? I'm not familiar enough with the G364 but
> here are a couple of reasons it may be faster:
> o The read access time to the v-ram can be long enough to
> ruin the performance completely. Optimizing copy loops
> in the driver is just waste of time.
> o Writes to the board might be pipelined so it can sustain
> a greater bandwith than reads.
> o Cached reads clobber the cache even if it's increases the
> read speed some.
> o Uncached reads is a pain if you have to do a lot.....
> o By rendering chars scanlinewise writes to the vram can be
> minimized. And of course optimizing scanline length depending
> on how long the lines are..
> o And many more reasons..
> It might be easier to get rerendering working than some kind of hardware
> scrolling. Also hardware scroll looses if you want to implement scroll
> regions as in VT emulation.
> Also, you don't have to consider vram configurations so much.
> You could measure the character rendering speed by filling the screen
> with N characters without scrolling N times and time it.
> Just a thought....
I think there are two differents things:
- Redrawing a new screen
- Scrolling one or X lines.
I don't know well VT Emulation, but for Linux/68K there are two fonctions
(scrollup,scrolldown) which use the graphic for doing a graph scrolling.
not a text scolling. I thought that 'vi' or 'more' or ... use the scroll of
VT emulation which use some graph scrolling...
But it was only a test. I think text scrolling imply a lot of memory moving .
PS: I like playing with graphics board