GBS-8220 RGB TO VGA Converter

[vanpeebles]

Can you list in detail how is it wired? Does sound strange!

[flyer.gio]

Can you list in detail how is it wired? Does sound strange!

R (red) from pin 7 (QL output) to the pin 8 of P11 (GBS-8220 white plug)
G (green) from pin 6 (QL output) to the pin 7 of P11 (GBS-8220 white plug)
B (blue) from pin 8 (QL output) to the pin 6 of P11 (GBS-8220 white plug)
CSync (composite sync) from pin 4 (QL output) to the pin 5 of P11 (GBS-8220 white plug)
Gnd (ground) from pin 2 (QL output) to the pin 1-2 of P11 (GBS-8220 white plug)

I have also connected the Vsync (QL's pin 5 to board's pin 3) without success.
I made a sync separator based on a LM1881 chip to get the composite sync from the QL pal video output (QL's pin 1 or 3 to feed the board's pin 5).
Another sync separator based on LM1883 to get both vertical and horizontal syncs to feed board's pins 3 and 4.
Many other experiments without success.

Finally I did the following check : connected a commercial DVD player to the board via the YPbPr connector, it works fine only while the dvd player's output is set to NTSC.

Could you please do the same check for me ?

[Dave]

The chipset on the board fully supports PAL - your vendor is incorrect. The board is manufactured for (originally) updating the displays of old video games, which were mostly designed around the PAL system due to the increased scan lines and lower frame rate, which suited gaming.

HTH

[vanpeebles]

I wired mine up like this

RGB cable -> P11 8-pin Board Cable counted along from the left GND first.

Green to Green Video Wire 7th wire on P11
Orange to Grey H.Sync Wire 5th wire on P11
Purple to Blue Video Wire 6th wire on P11
Blue to Red Video Wire 8th wire on P11
Yellow to Yellow V.Sync Wire 3rd wire on P11
Brown to Black Ground Wire 1st GND on P11

the 2nd GND and the 4th wire HS were not fitted.

The picture is looking at the front of the rgb cable

[belg4rion67]

I've the same problem of flyer.gio, (I think because in Italy signals are worst...)
In effect I've solded in same way p11 connector's wires to rgb plug of my two QLs and both of them have a lot of problem to sync Ql's signal.

[vanpeebles]

Did you hold down the auto button to make the board scan for a signal?

[XorA]

Did anyone having issues with sync add resistors as I suggested in an earlier post?

Since adding these the sync has been 100% rock solid for me.

I took the value from here

http://www.fruitcake.plus.com/Sinclair/ ... ableQL.htm

[flyer.gio]

The chipset on the board fully supports PAL - your vendor is incorrect.

Do you have a datasheet for that chipset ?

[flyer.gio]

Did you hold down the auto button to make the board scan for a signal?

Yes, of course.
Could you please try to conect a DVD player (or similar device) to the board via the YPbPr connector?
Then try to switch from PAL to NTSC... mine works in NTSC mode only...

[vanpeebles]

Have you tried the wiring the cable up to the settings I posted?