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Using LCD monitors with old VGA cards...

Anonymous Coward

Anonymous Coward

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Aug 11, 2004
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Shandong, China
I've noticed that whenever I attach my Samsung 191T to one of my older ISA systems, the image tends to suffer from a lot of distortion. The image is definetly readable, but it's nowhere near as clear as the output from modern VGA cards. The distortion that I am refering too is a little blurriness, and some diagonal waves that look like there is a layer of water running overtop of the image. I was wondering if perhaps anyone on this board knows how to construct a filter, or make modifications to the graphics adapter to clean up the output a little.
 
#INCLUDE twocents.h

That's what happens when you feed a high-resolution LCD monitor a 640X480 image. The image is blurry & crappy.

If anything, you could push the auto-adjust button (either a physical button or in the monitor's UI), this usually fixes problems like this. If anything more, you could adjust the more advanced settings in the UI.

Sorry if this sounded a little too...baby-talk-ish, but it's the best info I can provide. Hopefully another member will post better info to help you out...
 
Anything outside of the LCD monitors native resolution will look funny because it interpolates the screen. Another issue might be the resolution and refresh of the card in question, some modes will be interlaced and that might affect the display (LCD is 60Hz and the refresh could be below that on the card).

Nothing beats a decent CRT for older systems.
 
Hmmm....i'll have to look into the refresh rates I've been using. I thought they were set to 60Hz, but perhaps I am mistaken. Anyway, I am well aware of the fixed resolution of LCD monitors, and the problems I am experiencing are unrelated. I am running the monitor at its native resolution of 1280x1024, and even then it can be blurry. Infact, the higher resolutions seem to be the ones that suffer the most. I have no problems at 640x480.

It's really difficult for me to say if the graphics adapters were always like this at high resolutions, as in the early 90s I didn't have a good enough monitor to test them out. I currently only have one CRT available. It's a Sony IIFS 15". It seems to be on it's way out. I'd rather not invest in anymore CRTs. The basement is already full of crap as it is.

Basically, I stand by my original request. I want to know how to build a filter, or tips for tweaking the graphics adapter. I'm guessing that it probably just involves replacing a few capacitors.

...and just incase it helps, I'm using the following cards:

ELSA Winner 2000 4meg EISA/ISA
ATI Graphics Pro Turbo 2meg ISA
Hercules Dynamite Pro 2meg VLB
 
Hmm...you say that the monitor is sharp when connected to newer video cards, but fuzzy on older cards.

Perhaps a sub-standard video data cable? I know that doesn't seem to make sense, but a marginal cable can do weird stuff. I assume that you're directly connecting the monitor, not going through a switch box.

Does the monitor have an external power supply? Maybe the power supply is screwy?

Have you played with the monitor settings (video clamp, video voltage level, etc). Can't hurt to try different settings and see what happens.

Maybe you should consider clearing some space and getting a small crt monitor just for the older stuff :)

Kent
 
I'm thinking that 2Mb of VRAM ain't enough to do 1280 x 1024, even at 256 color depth, so the monitor or vid card is falling back to a lower rez, which seems blurry compared to the 'normal' rez.

--T
 
I think Vlad or Mbruttman used it to yell at me once a while back...during summer vacation...while I was barely getting enough nutrition...surviving off of Pepsi & junk food...causing mental instability...:p
 
Last edited:
atari2600a said:
#INCLUDE twocents.h
Click to expand...

But since this is not in the Standard C Library, it should look like:

#include "twocents.h"

wink.gif


Cheers,

80sFreak
 
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