Some RGB Cable Help

[Killjoyy27]

Hello All,

 

I am hoping to get some help to figure this out.

I have a Commodore 1084s D1 DB9 RGB connector

The RGB cable I have states that is is for d2 only and with that cable I cannot get vertical sync on my Amiga 1200

The monitor checks out with all other inputs so I don't believe its the monitor.

Is there a difference between the DB9 cables and could someone suggest where to get the proper cable or make another recommendation.

 

Thanks for your time

Edited February 24, 2022 by Killjoyy27

[oracle_jedi]

Are you getting a scrambled image on the 1084, or a rolling picture?

 

I had a rolling image problem with my 1084, and in the end had to modify the cable to use C-Sync and not H-Sync/V-Sync.  

[Killjoyy27]

Its a rolling issue. I will do some probing in the cable to see how its wired. 

[Daedalus2097]

There are many different variants of the 1084 family of monitors, and they vary in the sync requirement. Some require H-sync and V-sync, others require composite sync. The two systems aren't compatible - if your monitor requires composite sync, using just H-sync or V-sync will result in a rolling or flickering image, likewise if the monitor requires H-sync and V-sync and you only provide composite sync.

 

Ideally a cable would connect all three sync signals so it would work with any variant, but sadly that's not the case. Old ones crop up from time to time in Amiga groups and on eBay, and a few of the Amiga resellers sell cables, but it would be good to figure out what exactly your monitor needs. If you're checking out your cable, pin 7 is composite sync, pins 8 and 9 are the H- and V-syncs. According to the 1084S-D1 service manual, composite sync only is needed for RGB operation, so if your cable connects the other two instead, it won't work.