I know you're an expert here ... ;-0 I have the new version of my IRC client that does split screen console IO, and it is fast, but it is snowy too.
I think I need to be monitoring 3DA bit 1 to see when the coast is clear. Bit one indicated if vertical or horizontal retrace is happening.
- I think that vertical retrace time is 1.25ms. A rough calculation says that I have about 10000 cycles in that time to do my memory moves to avoid snow. How long is the safe time for horizontal retrace?
I'm assuming that my memcpy routine used something reasonable, like a REP MOV. What else might a library have done for an efficient memcpy? (I need to try to predict what they did so that I know how much memory to move during the retrace times.)
Thx,
Mike
I think I need to be monitoring 3DA bit 1 to see when the coast is clear. Bit one indicated if vertical or horizontal retrace is happening.
- I think that vertical retrace time is 1.25ms. A rough calculation says that I have about 10000 cycles in that time to do my memory moves to avoid snow. How long is the safe time for horizontal retrace?
I'm assuming that my memcpy routine used something reasonable, like a REP MOV. What else might a library have done for an efficient memcpy? (I need to try to predict what they did so that I know how much memory to move during the retrace times.)
Thx,
Mike