Vert Res. Horiz Freq H Sync Vert Freq V Sync
Polarity Polarity
350 lines 31.5 kHz pos 70.07 Hz neg
400 lines 31.5 kHz neg 70.07 Hz pos
480 lines 31.5 kHz neg 59.95 Hz neg
600 lines 35.2 kHz pos 56.24 Hz pos
Your problem is probably one of the following; 1. You are trying a mode your monitor won't support. 2. Your monitor is out of adjustment. 3. Your monitor is faulty. Possibly, the card or monitor is not "playing the rules", eg monitor expects one set of sync rates according to the sync polarities, and the card is sending out another (unlikely but...)
VGA monitor ID signals
Mike Diack asked about VGA monitors.Mike, I don't know if this is related to your problem or not, but IBM monitors have 3 pins dedicated to a "monitor ID" code, which is available to the VGA (or 8514/A or XGA) card, and also to the software. OS/2 uses it, for example, to automatically install the correct display support. The code:
PIN 4 PIN 11 PIN 12 Meaning
n/c n/c n/c No monitor attached
n/c n/c GND Mono monitor with no support for 1024x768
n/c GND n/c Color monitor with no support for 1024x768
GND GND n/c Color monitor with support for 1024x768
Maybe your projector is not providing the code to tell the VGA that it is there. If so, you can try modifying the plug. DISCLAIMER: I know this works for some Sony monitors, which support 1024x768 but don't provide the proper code to the PS/2, so they come up in 640x480. By changing the plug, the system sees the monitor as high-res-capable, and configures itself for 1024x768. Whether grounding pins in your plug will your projector, however, I can't say (although I doubt it).
VGA feature connector
Does anyone know how the VGA video feature connector operates? I would like to know which of the pins are inputs, which are outputs, and which are bidirectional (if any - and how the direction is selected).I have found a pinout for the connector:
Video Feature Connector Pinouts.
Pin Name Function
1 PD0 Dac Pixel data bit 0
2 PD1 bit 1
3 PD2 bit 2
4 PD3 3
5 PD4 4
6 PD5 5
7 PD6 6
8 PD7 7
9 - Dac Clock
10 - Dac Blanking
11 - Horizontal Sync
12 - Vertical Sync
13 - Ground
14 - Ground
15 - Ground
16 - Ground
17 - Select Internal Video
18 - Select Internal Sync
19 - Select Internal Dot Clock
20 - Not Used
21 - Ground
22 - Ground
23 - Ground
24 - Ground
25 - Not Used
26 - Not Used
And I assume that pins 1 - 12 are outputs, and 17 - 19 are inputs. Is this correct? The reason is this - I have a Rombo Media Pro+ video digitising card. It chroma keys its output into the vga monitor signal. However, although it is supposed to work with an ET-4000 with Hi-colour RAMDAC, the colours on screen behave as if the top 2 bits of colour information are missing, and red, green, blue signals are swapped around. Rombo has suggested that this may be due to insufficient buffering on the feature connector outputs, and is happy to sell me a buffer device for 50 pounds. I would rather save about 45 pounds, and build my own. I assume it would require (for example) a 74F244 buffer IC (or two).
Can anyone help? Any information on the feature connector would be highly appreciated!
Please could you reply by email :
ee90dhg@brunel.ac.uk
VGA feature connector
component side
pin function
1 PD0 (DAC pixel data bit 0)
2 PD1 (DAC pixel data bit 1)
3 PD2 (DAC pixel data bit 2)
4 PD3 (DAC pixel data bit 3)
5 PD4 (DAC pixel data bit 4)
6 PD5 (DAC pixel data bit 5)
7 PD6 (DAC pixel data bit 6)
8 PD7 (DAC pixel data bit 7)
9 DAC clock
10 DAC blanking
11 Ext. horizontal sync
12 Ext. vertical sync
13 Ground
back side
pin function
1 Ground
2 Ground
3 Ground
4 Select Internal Video
5 Select Internal Syncs
6 Select Internal DAC
8..11 Ground
VESA DPMS monitor power management
VESA DPMS is a monitor power managament standard designed for green PC concept. VESA DPMS defines method how a screen saver program can put monitor to power save state when it blanks the screen. The signalling to monitor is handled using normal monitor sync signals: screen saver can turn one of sync signals (or both) off and the monitor knows from this that it must turn to power save mode.
VESA DPMS power states:
NORMAL STANDBY SUSPENDED OFF
H-sync On Off On Off
V-sync On On Off Off
Power level 100% 80% <30w> NUTEK monitor power management
NUTEK is a Swedish standard for monitor power management so that screen saver program can turn monitor to power save mode when computer is not used for a while. NUTEK works using the following pronciple: when the picture signa coming to the monitor has been totally black for lomg enough, the monitor turns to power save mode. When there is other than just black coming to monitor, then the monitor turns back to normal operation.
VESA modes
This list is not complete list of SuperVGA modes standardized by VESA. For complete documentation check VESA VBE standard.
--------V-104F02-----------------------------
INT 10 - VESA SuperVGA BIOS - SET SuperVGA VIDEO MODE
AX = 4F02h
BX = mode
bit 15 set means don't clear video memory
Return: AL = 4Fh function supported
AH = status
00h successful
01h failed
SeeAlso: AX=4F01h,AX=4F03h
Values for VESA video mode:
00h-FFh OEM video modes (see AH=00h)
100h 640x400x256
101h 640x480x256
102h 800x600x16
103h 800x600x256
104h 1024x768x16
105h 1024x768x256
106h 1280x1024x16
107h 1280x1024x256
108h 80x60 text
109h 132x25 text
10Ah 132x43 text
10Bh 132x50 text
10Ch 132x60 text
---VBE v1.2---
10Dh 320x200x32K
10Eh 320x200x64K
10Fh 320x200x16M
110h 640x480x32K
111h 640x480x64K
112h 640x480x16M
113h 800x600x32K
114h 800x600x64K
115h 800x600x16M
116h 1024x768x32K
117h 1024x768x64K
118h 1024x768x16M
119h 1280x1024x32K
11Ah 1280x1024x64K
11Bh 1280x1024x16M
Index: video modes
Values for S3 OEM video mode:
201h 640x480x256
202h 800x600x16
203h 800x600x256
204h 1024x768x16
205h 1024x768x256
206h 1280x960x16
208h 1280x1024x16
211h 640x480x64K (Diamond Stealth 24X)
212h 640x480x16M (Diamond Stealth 24X)
301h 640x480x32K
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