Interesting. Very interesting indeed. HGC graphics and specially text were WAY MUCH better than crappy CGA imho. Why the greenish tinge though?

Was there a correct colour scheme?
Call it nostalgia, but my days lack monochrome "green"
(easy enough to program any other mono scheme, such as amber or grey)
Mixing 4 colours looks quite impressive too.

Resolution - 720X350 pixels and a beautiful 9x14 font set.
(I think VGA default textmode is 640x400 with 8x16 fonts)

(Still working on fonts..)

Default vga is 720x400 with 9x16 fonts.

Current CVS already has some support for hercules graphics mode though and you can further help detection of it with setting the machine variable in the config file

Thanks Harekiet,

Have the second graphics page up, not able to CVS so here is the
change you need to make to vga_misc.cpp:

-/* Hack around like it looks we are in 0xb000 segment */
- vga.gfx.miscellaneous=(vga.gfx.miscellaneous & ~0x0c)|0x0a;

+/* Hack so it it looks like we are in 0xb000 or 0xb800 segment */
+ if (val>>7) vga.gfx.miscellaneous=(vga.gfx.miscellaneous)|0x0c;
+ else vga.gfx.miscellaneous=(vga.gfx.miscellaneous & ~0x0c)|0x0a;

Now you can run any other hercules apps that dont make use of bios calls
(still finishing those).

Did it slightly different now so you don't have the black lines over the screen. Always thought the hercules had only 2 8kb pages in the 0xb000-0xb7fff range. I should read the documentation better 😜

Yes that banding looks terrible and why both example images has colour. Shouldn't they be b/w only (1bpp)?. 😀

i think you are free to choose your own pallete (at least if you're coding it)

Thanks Harekiet, that re-write looks much better than my efforts.
AND pictures look much better without the scan lines!

Now there still seems to be one last bug,
(looses visiblity (ie wrong page) shortly after your screenshot);
I'll try comparing sources, I think the 'hercules mask' is sticking ...

**Edit:
vga_misc.cpp: Line 225

}
}
if (vga.herc.enable_bits & 0x2) {
mask|=0x80;
-- VGA_SetupHandlers();

}
vga.herc.mode_control=(vga.herc.mode_control & ~mask) | (val&mask);
++ VGA_SetupHandlers();
break;

hehe yeh it sets up the new handlers before updating the value, i'll give it another write and lose the mask thingie a bit.

--edit

Hope it works correctly now 😀

Bit of a challenge this one provided, hopefully its now stable:
This code Fixes INT10-function 3 (Video Scroller support):

add the following to INT10_CHAR.CPP
(Somewhere just below the #includes ..)

static INLINE void CGA2_CopyRow(Bit8u cleft,Bit8u cright,Bit8u rold,Bit8u rnew,PhysPt base) {
Bit8u cheight = real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
PhysPt dest=base+((CurMode->twidth*rnew)*(cheight/2)+cleft);
PhysPt src=base+((CurMode->twidth*rold)*(cheight/2)+cleft);
Bitu copy=(cright-cleft);
Bitu nextline=CurMode->twidth;
for (Bitu i=0;i<cheight;i++) {
MEM_BlockCopy(dest,src,copy);
MEM_BlockCopy(dest+8*1024,src+8*1024,copy);
dest+=nextline;src+=nextline;
}
}

static INLINE void CGA2_FillRow(Bit8u cleft,Bit8u cright,Bit8u row,PhysPt base,Bit8u attr) {
Bit8u cheight = real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
PhysPt dest=base+((CurMode->twidth*row)*(cheight/2)+cleft);
Bitu copy=(cright-cleft);
Bitu nextline=CurMode->twidth;
attr=(attr & 0x3) | ((attr & 0x3) << 2) | ((attr & 0x3) << 4) | ((attr & 0x3) << 6);
for (Bitu i=0;i<cheight;i++) {
for (Bitu x=0;x<copy;x++) {
mem_writeb(dest+x,attr);
mem_writeb(dest+8*1024+x,attr);
}
dest+=nextline;
}
}

............ Then replace the following ...........

case M_TEXT16:
TEXT_CopyRow(cul,clr,start,start+nlines,base);break;
--// case M_CGA2:
++ case M_CGA2:
++ CGA2_CopyRow(cul,clr,start,start+nlines,base);break;
case M_CGA4:

... AND ...

case M_TEXT16:
TEXT_FillRow(cul,clr,start,base,attr);break;
--// case M_CGA2:
++ case M_CGA2:
CGA2_FillRow(cul,clr,start,base,attr);break;
case M_CGA4:
CGA4_FillRow(cul,clr,start,base,attr);break;

Now you can play King's Valley (CGA/Tandy)!
King's Valley