Subject: Re: DEC - VGA video adaptor?
To: None <>
From: John Maier <>
List: port-vax
Date: 07/02/2001 13:50:09
If you have experience with low-level electronic work, this might be of help:

There are some errors in the circuit diagram of the LM1881N (Pin 1 is not a
HSYNC out but COMPOSITE -- yes I've told him) but read the spec sheet and it
will all become clear.   I submitted the NAND-AND gate circuit just below the
LM1881N diagram, to split the Hsync from the composite if your monitor cannot
handle a Composite on the HSYNC--some are rumored to be able--mine can't.  It
seems to have something to do with the expected timing of the signals,

Also I have found that some monitors with auto powersave just have problems, so
not all monitors work, so if you can either turn off the autopower save or have
a monitor that don't have it, your better off.  I've seem similar problems with
MAC VGA adaptors at resolution above 640x480 but not with not power saving
monitors <shrug>.

Don't ask me where you can get the elusive EL4583 from Elantec; every place I've
ever found them listed, say they are out of stock with no time frame for getting
any in :-(  But if you find some, let me know, I'd like to try one out!

DigiKey is a good place to get the LM1881N and other parts.

John Maier - Administrator
Midamerica Internet Services
ICQ# 38643380
/ Nothing great was ever achieved without
/ enthusiasm. --- Ralph Waldo Emerson