scart on nms 8250/55/80

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Por olliraa

Champion (297)

Imagen del olliraa

10-03-2011, 10:31

Ok, here's the schematic:

http://koti.mbnet.fi/olliraa/scartvga.jpg

BEWARE: I know absolutely nothing about electronics and I hate soldering :) My projector seems to be very versatile concerning different types of analog and digital video signals. Some other "vga-compatible" displays almost certainly won't work with this adapter.

If/when someone knows how to make my adapter better, please comment :)

Por olliraa

Champion (297)

Imagen del olliraa

11-03-2011, 09:04

SUCCESS! THe problem was indeed the lousy scart connector. I built a new adapter and image quality is very impressive. Here's a photo (84" screen) Smile Text looks very good considering that it's scaled to the native resolution of the projector Smile

http://koti.mbnet.fi/olliraa/msxrgb.jpg

Por bartl68

Expert (86)

Imagen del bartl68

11-03-2011, 11:40

i did so you have done with the schematic, but my letters supposed to be white are black, strange!!

Por olliraa

Champion (297)

Imagen del olliraa

11-03-2011, 15:44

@bartl68

Did you check the numbers of the pins from the "casing" of the connector? My schematics doensn't have any "from solder side etc" kind of standard. I just look the pin numbers from the "casing" of the connector. Sounds like your colour pins may be somehow swapped.

Por jltursan

Prophet (2256)

Imagen del jltursan

11-03-2011, 19:14

Well, seems that the Sanyo projector is very "signal friendly". For a different device must be a must to ground all the signals, not only the shield; so red, green, blue and composite must be tied together.

Por Manuel

Ascended (16037)

Imagen del Manuel

11-03-2011, 22:57

RGB rules! Razor sharp picture!

Por olliraa

Champion (297)

Imagen del olliraa

12-03-2011, 07:35


Well, seems that the Sanyo projector is very "signal friendly". For a different device must be a must to ground all the signals, not only the shield; so red, green, blue and composite must be tied together.

If I get a good quality picture without the grounding of r,g,b and composite (as I do now), is there anything to gain by creating another adapter with those pins connected? I'm just curious here Smile

Por bartl68

Expert (86)

Imagen del bartl68

12-03-2011, 08:45

@jltursan , thnx for the tip, i have grounded all signals like rgb & hsync to ground 21, so i have the right picture now !!!

so the problem is almost solved, i managed also to connect a vga monitor to my nms8250+, but i miss only 4 char at the left in 80 colums mode, my monitor goes into 640x200 mode at 50hz, is there something to do about that?

Por olliraa

Champion (297)

Imagen del olliraa

12-03-2011, 11:19


i have grounded all signals like rgb & hsync to ground 21, so i have the right picture now

Now it's my turn to ask you Wink How exactly did you connect the various grounds together? Could you describe that in detail?

Por bartl68

Expert (86)

Imagen del bartl68

12-03-2011, 13:11

@olliraa

i place a wire on the scart between the following pins : 5 to 9 to 13 to 17 to 21 in a loop, and one wire at the vga from pin 5 to 6,7,8 and a drop of thin between 6 & 11, that's all i did.

@others?
when i do width 37 then the screen is good, but width 40 and higher i miss some chars at the left, cause my monitor detects 640x200 at 50hz. i guess it has to be like 544x480 at 50hz ?

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