DB15 to HD15 adapters and dip switches

[Opardalis]

Can someone shed some light on these adapters? The one I have has 6 DIP switches (comp sync 1, comp sync 2, sync on V, sync on H, sep sync, sync on green).

Amazingly, on the non-setting mode (all switches set to off), it worked for my IIfx (SuperMac Series IV video) with a modern 25" LCD display (most likely auto-sync).

However, I've been trying to get it to work on some LC II like systems with onboard video, and nothing works... Sometimes I get "No Signal", other times I get out of range.

Too many combinations to try them all, but it would help if I knew where to start. For example, on the LC 475 onboard video, what mode should I try, sync on green? I have a smaller 15" LCD I can try as well.

-John

 

[olePigeon]

There used to be a thread somewhere with a bunch of the VGA adapter manuals scanned in.  The switches can do different things depending on the brand.

The issue here may be with the LCD and not with the adapter.  Many LCDs can only do 60Hz.  Getting them to sync at 62Hz, 68Hz, 70Hz, 72Hz, 75Hz, etc. will not work unless you have an LCD that supports the different refresh rates.

It'd be worth trying the 15" LCD, it may be old enough that it is designed to sync like a CRT and support different refresh rates.  Might have better luck getting that 512x384 (640x480 if you have the VRAM upgrade.)

 

[joethezombie]

Here's a few of the old threads.  Maybe one day the pictures will get fixed and we can have nice things again.

https://68kmla.org/forums/index.php?/topic/25051-dip-switch-settings-for-mac-to-vga-adapter/

https://68kmla.org/forums/index.php?/topic/15929-video-adapter-docs-scan-dump/#p159651