The constant _MAXRESMODE selects the highest possible resolution for the graphics adapter and monitor currently in use. The constant _MAXCOLORMODE selects the graphics mode with the greatest number of colors. These constants work with all graphics adapters except the MDPA. These constants never select the _SRES, _XRES, or _ZRES mode to avoid possible monitor damage and to guarantee that the selected mode works. (See Table 9.3.)
Table 9.3 Constants for Maximum Resolution and Color
| Adapter/Monitor | _MAXRESMODE | _MAXCOLORMODE |
| CGA | _HRESBW | _MRES4COLOR |
| EGA color | _HRES16COLOR | _HRES16COLOR |
| EGA ecd 64K | _ERESCOLOR | _HRES16COLOR |
| EGA ecd 256K | _ERESCOLOR | _ERESCOLOR |
| EGA mono | _ERESNOCOLOR | _ERESNOCOLOR |
| HGC | _HERCMONO | _HERCMONO |
| MCGA | _VRES2COLOR | _MRES256COLOR |
| MDPA | Fails | Fails |
| OCGA | _ORESCOLOR | _MRES4COLOR |
| OEGA color | _ORESCOLOR | _ERESCOLOR |
| VGA/OVGA | _VRES16COLOR | _MRES256COLOR |
| SVGA* | _VRES256COLOR | _VRES256COLOR |
* If your SVGA adapter does not support _VRES256COLOR, _MAXCOLORMODE selects _ORES256COLOR. If _ORES256COLOR is not supported either, the VGA modes for maximum color and maximum resolution are used.