On Tue, Sep 12, 2017 at 08:25:44AM +0200, Gerd Hoffmann wrote:
Hi,
Minor note - I realized after I sent my last patch that doing:
SET_LOW(sercon_enable, (mode <= 0x07));
I don't think so. 0,1,2,3,7 are text modes, but 4,5,6 not.
It's safe to enter the C code on 4,5,6 though. Also, I don't think it was unusual to write text while in cga mode. (CGA support isn't a priority though.)
Oh. So the char write int10h calls work in cga mode too?
Yes.
On SeaVGABIOS, text writing now works in all graphic modes, though not all vgabios support that. The original bochs vgabios didn't support it in "direct" or "packed" modes, and I think it was broken for years in planar mode. So, it's rare for text writing to be seen in any mode above 7. (It's also rare for anything to go into cga mode today, but for ancient programs, it would not have been unusual to write out text in cga mode.)
-Kevin