Another 15khz LCD Monitor

[Ami_GFX]

I've had this monitor--a Cornea CT1702T--since last spring. I just discovered it can do native 15khz Amiga modes yestderday. Normally I used a Flicker Magic internal scan doubler/flicker fixer with my A4000. I set up a direct out through a vga switch box so I can use the 31khz AGA modes and to my surprise, the monitor actually does the 15khz native Amiga modes too. There are some issues of display positioning that can be fixed with the right overscan settings. Unfortunately, this doesn't work with the boot menu or Video Toaster and the Toaster display is very off center. The interlaced modes have the usual annoying flicker but the display is otherwise very good. This has ended up being a great Amiga LCD. It can sync down to 48hz vertical and has no problem with PAL. It has composite and S-Video inputs which are nice for working with the Toaster. It is very similar to the Samsung 150MP and 170MP monitors which are also supposed to do native 15khz Amiga modes too. I have a 150MP and haven't gotten it to work at 15khz but I think it can only do this with composite sync--scart uses composite sync as well--and I have to make a special cable to test it with composite sync. The Cornea CT1702T is working at 15khz on separate horizontal and vertical sync.

These monitors are around 10 years old and Cornea is long out of business. They do show up on the used market quite a bit.

[Ami_GFX]

Now I've got the Samsung Syncmaster 150MP out again. The Cornea and Samsung monitors both have the same folding stand design, both will do PAL from the VGA port--I've got a Magnavox monitor that does PAL from the composite and s-video inputs but not the VGA port. I had no luck with 15khz Amiga modes with this monitor in spite of what the Big Book of Amiga Hardware says. There's an old post on Amiga.org that says the same thing but I found another reference that says it only works in one of it's modes which I assume is composite sync on the vga pin that normally carries horizontal sync. SCART also uses composite sync and the antenna connector on this TV/monitor is the European version which makes me think it was sold in Europe with a SCART connector.

[Ami_GFX]

There are some vertical stripes, more noticible in the pictures than when using the monitor. I have the monitor's clock frequency set as low as it can go. The lower the clock frequency, the finer the vertical lines but the screen is less stretched and more of it fits in the monitor's display area.

The Samsung 150mp defintely won't sync to 15khz on separate horizontal and vertical sync. I'm going through my Amiga stuff to see if I have something that I can make a 23 pin to 15 pin VGA cable with composite sync on the horizontal pin. Complicated because I use a sync strainer to be able to use the Toaster with monitors without composite sync and I've modded the Flicker Magic to get it's sync signal from the output of the sync strainer. The Flicker Magic has problems with interlaced video in Toaster genlock mode and the and the 15khz out on the Cornea monitor is much better but off center.