claunia/86Box
1
0
Fork 0
Code Issues Pull Requests Actions 3 Packages Projects Releases Wiki Activity

updated comment in monitor detection (vid_svga .c)

Browse Source
This commit is contained in:
Akamaki
2025-02-15 11:29:44 +09:00
parent dc7e6c2d7f
commit a850821ecb
1 changed files with 6 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/video/vid_svga.c
View File

@@ -511,10 +511,12 @@ svga_in(uint16_t addr, void *priv)
}
else
{
// The Display Adapter has own Monitor Type Detection bit in the different I/O port (I/O 3E0h, 3E1h).
// When the monitor cable is connected to the Display Adapter, this port returns the value as no cable connection.
// The Power-on Self Test of PS/55 tries detecting the monitor on the planar VGA.
// If it fails, then the POST reads the NVRAM set by the reference diskette, and sets the BIOS Data Area (Mem 487h, 489h).
/*
The IBM PS/55 Display Adapter has own Monitor Type Detection bit in the different I/O port (I/O 3E0h, 3E1h).
When the monitor cable is connected to the Display Adapter, this port returns the value as 'no cable connection'.
The POST of PS/55 has an extra code that tries detecting the monitor on the planar VGA.
If it fails, then the POST reads the NVRAM set by the reference diskette, and updates the BIOS Data Area (Mem 487h, 489h).
*/
if (svga->vgapal[0].r >= 10 || svga->vgapal[0].g >= 10 || svga->vgapal[0].b >= 10)
ret = 0;
else