carlos12
Experienced Member
Hi there!
I'm now messing with the CGA registers. My goal is to achieve horizontal hardware scrolling on CGA 4 color mode without flickering. I achieved to reduce the horizontal displayed on the CGA (emulated, I have no real CGA to play with):
But this has no effect on EGA or VGA. According to the documentation, that register number has another function on the EGA/VGA.
So my question is: is there an EGA register that sets the horizontal displayed? I looked on the documentation and on Wilton's book and I found vertical displayed but had no luck with the horizontal ones. My idea is to use a detection code to tell if we are using a CGA or an EGA/VGA, so setting the adequate ports for reducing the visible width on each adapter, as I want my code work on as many adapters as possible, not only pure CGAs.
Thank you so much!
I'm now messing with the CGA registers. My goal is to achieve horizontal hardware scrolling on CGA 4 color mode without flickering. I achieved to reduce the horizontal displayed on the CGA (emulated, I have no real CGA to play with):
Code:
outp (0x3D4,1);
outp (0x3D5,39);
But this has no effect on EGA or VGA. According to the documentation, that register number has another function on the EGA/VGA.
So my question is: is there an EGA register that sets the horizontal displayed? I looked on the documentation and on Wilton's book and I found vertical displayed but had no luck with the horizontal ones. My idea is to use a detection code to tell if we are using a CGA or an EGA/VGA, so setting the adequate ports for reducing the visible width on each adapter, as I want my code work on as many adapters as possible, not only pure CGAs.
Thank you so much!