nfg.forums

What I'm trying to do is connect a PS1 to a Commodore 1084S monitor using RGB. I've wired up the SCART adaptor as best I can, and I set up an LM1881 sync chip to convert composite video into composite sync. However, when I turn on the PS1 I get a rolling picture with scrambled colors.

   I've followed the diagrams for plugging in the LM1881 as closely as possible, but it doesn't seem to do any good. I get a rolling scrambled mess no matter what I do; leaving the sync chip out gives the same results, and I've double-checked the wiring. In fact, disconnecting the sync line entirely gives the same results, even though there's no problem with the wire itself. I'm powering the chip off the SCART switching voltage- is it possible that I'm missing something? Do I need to do something 1084-specific to the sync line?

   The monitor is in perfect shape, BTW. I just tested it with an Amiga. Does anyone know what's going on here?

That's got to be a sync problem from your description. I'd check check and RECHECK that LM1881, but as it seems you've done that would you suppose the chip could be bad? Got another one to try? What about a console that sends sync instead of video? Testing either would tell you something.

Times like these make you really appreciate the monitors that can take video, when you get ahold of them. (Sony PVM series, Mitsubishi Megaviews, etc. etc.)

my 1084 can take composite video as sync, and my 1084s doesnt even have scart, it's d-sub. but theyre both pal.

anyway. have you got ground connected properly? you can get whached colour and bad sync if you forget that, or connect it wrong.

Back when my 1084 and CM8833 (near identical monitor) were still healthy, I had my PS1 hooked up to them without any problems?

You dont need to use a LM1881.

I would also suggest checking your cable/connections.

It's been ages but i'll try dig up the cable i used.

   Trying it without the LM1881 gave identical results. I've checked the ground wires and can't find anything wrong.

   I've gone through two sync chips so far, tried another playstation, and checked the continuity with a multimeter. No dice. Is it easy to burn these chips out during soldering? What temperature setting do I need to use if that's the case?

Computolio,
Why don't you buy a cheap, third party playstation to SCART lead? If you're determined to build your own then follow this diagram. In the case of a 1084 monitor, connections to pins 16 and 8 can be omitted. I've got no idea why you think a sync stripper circuit is required...

   Thing is, that's what I'm using.

   OK

   Now it works perfectly. After trying again I realised what the problem was. I (get ready for this) got the 1084 pinout BACKWARDS.

   Yeah.

Hmm. is it composite sync on PSX or composite video ?

Composite video.

If you have a standard 1084 monitor you should have a male DB-9 plug in the back and the following pinouts:

1-Ground
2-Ground
3-Red
4-Green
5-Blue

6-NC
7-Composite Sync
8-NC
9-NC

However, on the 1084S and DS models there is a FEMALE DB-9 plug and the pinouts are REVERSED like the following:

1-Blue
2-Green
3-Red
4-Ground
5-Ground

6-NC
7-NC
8-Composite Sync
9-NC

Yet another reason why Commodore is no longer around.....

The PAL Philips based 1084 and 1084S monitors will accept composite video as sync.  These are pretty much the only 1084 monitors found around here.  The later model with the power switch on the back have a 9 pin D connector, the earlier ones with the power switch on the front have either a SCART connector or a 6 pin DIN connector.  

The Toshiba based 1084 monitors that seem to be more common elsewhere will not accept composite video as sync and require the LM1881 or similar sync seperator circuit.  

This has caused much confusion in the past when I have told people how to wire up cables.  

yeah, no such thing as a 'standard' commodore 1084 monitor.

My 1084S-D1 is with D-sub9 and it can't accept composite video for RGB. Hopefully i bought 3x LM1881 and soon solve my problem. B)