CompuServe Messages

Karl, Quoting (without permission) from the "AGA Graphics Supplement": "The standard VGA horizontal scan rate is 31.5 kHz. Most, but not all, VGA-only monitors can also display the 27 kHz scan-doubled modes, DBLNTSC and DBLPAL. "If you are attempting to use a VGA monitor with the DBL or MULTISCAN modes, and it does not display those modes correctly, activating the VGAOnly monitor driver [note: it's not really a monitor driver, and nothing is said here about *how* to activate it] may help. It modifies the scan rates slightly, at the cost of some scrolling artifacts in the display. The next tables show the normal scan rate followed by the rates as modified by VGAOnly. "Monitor Driver Horizontal Scan Rates Vertical Scan Rates "============== ===================== =================== "DBLNTSC 27.66 kHz / 29.20 kHz 58 Hz / 59 Hz "DBLPAL 27.50 kHz / 29.45 kHz 48 Hz / 50 Hz "EURO72 29.32 kHz / 31.43 kHz 69 Hz / 70 Hz "MULTISCAN 29.29 kHz / 31.44 kHz 58 Hz / 60 Hz "A multiscan monitor can potentially display any of the above, plus the following: "Monitor Driver Horizontal Scan Rates Vertical Scan Rates "============== ===================== =================== "SUPER72 23.21 kHz / 24.62 kHz 71 Hz / 72 Hz" You should have six entries for DBLNTSC in your ScreenMode prefs editor: High Res (640×200 scan-doubled) High Res Laced (640×800 interlaced) High Res No Flicker (640×400 non-interlaced) Lo Res (320×200 scan-doubled) Lo Res Laced (320×800 interlaced) Lo Res No Flicker (320×400 non-interlaced) The Super-High Res modes have a horizontal sync of around 15.5 kHz; they are unaffected by VGAOnly. A VGA monitor cannot display a Super-High Res screen. I didn't drop by here yesterday (and I'm replying off-line with AutoPilot), so I apologize if any of this is redundant. -Dave (via AutoPilot)