19 Mar
2005
19 Mar
'05
2:11 a.m.
On Fri, 18 Mar 2005 16:47:14 -0800 (PST), Eric Smith <eric at brouhaha.com>
wrote:
Tony wrote:
There were some tricks with LP displays. One was to generate "sensitive"
fields with a rather dark background which was set to black for every
second frame. The decay was shorter for very dark areas to start with, and
to make it work with a cheap pen you just halved the refresh frequency.
--
-bv
I can tell you that although the MDA card has a
light pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance).
Long persistence phospor doesn't preclude the use of a light pen, it
just introduces some limitations on the usage model. The DEC Type 30
and 340 displays as used on the PDP-1 through PDP-10 use a P7 phosphor
which has very high persistence, yet light pens were commonly used with
them.