Differences

This shows you the differences between two versions of the page.

--- av:dreamcastav [2010/04/28 04:39] – gregory
+++ av:dreamcastav [2019/08/27 20:45] (current) – external edit 127.0.0.1
@@ Line 21: / Line 21: @@
 <box round warning 40% |15kHz/31kHz RGB Note:> Most Dreamcast games are compatible with both 15kHz and 31kHz RGB modes (SCART and VGA) However a small percentage are not compatible and will show either a warning message on the Dreamcast's menu, or a blank screen. </box>
-If a certain game will not boot in either RGB mode it can sometimes be 'forced' into RGB by fitting a break-before-make switch between ground and one, or both, mode select pins. Once this is done power up the Dreamcast with the switch in the 'standard mode' (Neither pin grounded) and flick the switch after the game disk has already started to be read (When loading original GD-ROM's you will hear a 'beep' sound from the drive at this point) this can often trick incompatible games into the desired mode. You can find more info on some [[http://cvresumewritingservices.org/professional-resume.php|professional resumes]] sites.
+If a certain game will not boot in either RGB mode it can sometimes be 'forced' into RGB by fitting a break-before-make switch between ground and one, or both, mode select pins. Once this is done power up the Dreamcast with the switch in the 'standard mode' (Neither pin grounded) and flick the switch after the game disk has already started to be read (When loading original GD-ROM's you will hear a 'beep' sound from the drive at this point) this can often trick incompatible games into the desired mode.
 ==== Mode Selection Signals Chart ====
 When the mode select pins are used certain signal outputs are enabled or disabled:-
-^Pin^Description^Standard Mode^15kHz RGB (SCART)^31kHz RGB (VGA)^
+^Pin^Description^Standard 'TV' Mode^15kHz RGB (SCART)^31kHz RGB (VGA)^
 |  1  | Ground  | Ground | Ground | Ground |
 |  2  | Right Audio  | Right Audio  | Right Audio  | Right Audio  |
@@ Line 34: / Line 34: @@
 |  6  | Mode Select 1  | Unused | Unused | Grounded |
 |  7  | Mode Select 2  | Unused | Grounded | Grounded |
-|  8  | Vertical Sync  | ? | ? | V-Sync |
+|  8  | Vertical Sync  | VSYNC? | VSYNC | VSYNC |
-|  9  | Horizontal Sync  | ? | ? | H-Sync |
+|  9  | Horizontal Sync  | HSYNC? | HSYNC | HSYNC |
-| 10  | Composite Sync| ? | C-Sync | ? |
+| 10  | Composite Sync| ? | CSYNC | Disabled |
 | 11  | S-Video Chroma (C)| S-Video Chroma | ? | Disabled |
 | 12  | S-Video Luma (Y)| S-Video Luma | ? | Disabled |
@@ Line 43: / Line 43: @@
 | 15  | Green  | Disabled | Green | Green |
 | 16  | Red  | Disabled | Red | Red |
+Note:- According to the [[schematics:console_related_schematics#dreamcast|schematics]] the HSYNC and VSYNC signals come directly from the 'HOLLY' GPU and are sent to both the DAC/Encoder and the AV port, which means they are likely active in all modes (Even standard 'TV' mode, when no RGB signals are present) However CSYNC is generated by the DAC/Encoder, so is unfortunately only active in specific modes.
 ==== Other ====