68kMLA Classic Interface
This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.
| Click here to select a new forum. | | 12" Monochrome on modern Mac | Posted by: Dandu on 2019-08-02 09:44:19
Hi,
I have a little problem. I have found a 12" monochrome monitor (High Res) and i will try to connect the display to a modern Mac. And it will not work : https://www.journaldulapin.com/2018/08/17/crt-apple/
The display is working with an old Mac LC, with a Power Mac G3 (beige), but not with a modern computer. It's a fixed definition model (640x480@66) but when i try with DA15 to DB15 adapter, i can have an image, but not the synchronisation. This page say the display use a composite sync, but even with an adapter who can use (i presume) the composite sync, it will not work.
Can you help me ? Is there a special adapter for that ?
| Posted by: Trash80toHP_Mini on 2019-08-02 10:02:52
Older Macs supported the refresh rates of legacy displays, but modern computers dropped it at some point. The link you posted appears to spec a PowerMac G3, so it works. Any newer Mac or VidCard that doesn't have a 66.7Hz output for that legacy fixed frequency displays won't work sync up. Passive adaptation is a one way street, legacy mac resolution outputs will usually work as inputs for a multisync display, but not in the opposite direction to a legacy display.
| Posted by: Dandu on 2019-08-02 10:20:02
Actually, i can force 640x480 @ 66 with SwitchresX, it's not the problem. The problem is the sync : i see the image "scrolling" when i use the correct timing.
| Posted by: Trash80toHP_Mini on 2019-08-02 10:21:41
Is sync on the green line?
| Posted by: Cory5412 on 2019-08-02 11:27:27
You might try 67Hz instead of 66 or 66.7, but I've never seen any examples of this working.
It is somewhere in the late Power Mac G4 era that support for the old fixed-sync displays stopped. (I actually should test this with my TiBook@1GHz and my QS'02 at some point.)
I don't believe SoG is the issue, to my recollection only the portrait display and maybe the 21-inch Macintosh Color Display used that sync type.
| | 1 |
|