Re: Dapple Wishlist 0.67

[steve@dosius.zzn.com (Dosius)]

mjmahon@aol.com (Michael J. Mahon) wrote in message news:<20020906031109.02042.00002569@mb-mu.aol.com>...
> Dosius wrote:
> 
> <snip>
> >Dapple is a 16-bit emulator (!), because Turbo C++ 1.01 (
> >http://community.borland.com/museum ) is freeware and has GOOD online
> >help.  I did use tcc-specific stuff :(  I will need to find a good,
> >fast 640x200x16 plotter though, don't know if BGI is fast enough.
> 
> Steve, I don't know how you are handling the video translation, but
> a very efficient way is to drive video updates by "vertical blanking"
> interrupt.
> 
> At the end of each raster refresh, you compare the Apple II emulated
> video memory with the previous version, and do the updates for any
> changes.  This eliminates any need to consider video while the
> Apple II emulation is running, except once per video refresh time.
> 
> On a fast PC with 64-bit (or more) data paths, the 4KB or 8KB compare
> takes a trivial time, and video card updates are done only when
> differences are detected.
> 
> -michael
> 
> Check out 8-bit Apple sound that will amaze you on my
> Home page:  http://members.aol.com/MJMahon/
I just keep an onscreen and an offscreen buffer, switching them as
needed to pageflip, meaning I translate the video as it is created and
then blit it all when the page changes.  (Hard to explain. ^_^)