3 ms·

Can't remember too much modex assembly, but ... Does the CGA have a vsync non-display blanking interval that could prevent tearing?

• bryanlarsen 13y ago
  In the video when he talks about future possible enhancements he mentions that the system timer could be set to provide an interrupt to use for page flips. So it sounds like the answer is technically no, but practically yes.
  • ballard 13y ago
    It looks like he's using text mode. IIRC text on VGA (not this) has 4 pages and supports blanking interval stuff by virtue of VGA. 80x25 is 80x9 x 25x16 = 720x400. The character maps are actually 8x16 with the right pixel duplicated into the 9th. And in VGA there are two character planes (512 chars total), which explains Norton weird cursor that could go anywhere later copied by FreeBSD and others. It maybe possible to change the character planes to be optimized for drawing. That would be cool.