27 Dec
2012
27 Dec
'12
3:25 p.m.
From: Fred Cisin <cisin at xenosoft.com>
Chuck pointed out that FREQUENCY was more
significant,
and could DESTROY a 5151, and that voltage [if it WERE
a problem] needed but a resistor network.
On Wed, 26 Dec 2012, Chris Tofu wrote:
C: Note though that I never did say "IBM
5151" which was notoriously
sensitive.
That is true.? You said "an Eagle 5151 clone"
Some people interpret "clone" to mean the "exact same thing
from another manufacturer".
Did you mean
"somewthing vaguely similar, with same specs,
but without the known design weaknesses"?
C: I didn't manufacture nor own a detailed description of it's innards. There are
other 5151 workalikes out there I'm sure.
??? I would have thought you know what the Eagle PC is. It's the monitor that sits on
top.
I still could be wrong, but whereas Chuck states that
30 khz
is what we're shooting for, I would bet the farm that the AT & T's
horizontal scan rate is actually much lover (23-25 khz). I still could
be wrong, but then again we're not talking about a fixed frequency vga
monitor in reality.
I don't know anything about such things.
C: So why you bugging me?
I'm just trying to clarify what is being argued about.
It would help ENORMOUSLY to get it straight whether you,
or Chuck, have actually DONE what either of you suggest,
or are merely speculating about possibilities.
"you can", "you could", "would be" do NOT answer that!
C: I'm sure you're old enough to remember horizontal and vertical controls on your
tv. Remember when it used to roll? You'd reach around back and twist a trimpot (or
capacitor, don't know nor care) to make it stop. Well in effect what you were doing
was altering the vertical scanning frequency, more then likely due to drift (cold set?).
Every monitor has that control, and also one to alter the hsync frequency (if it was off,
you'd see a "taring" or stretching of the picture from side to side. No I
haven't tried it, but being that a 5151 (clone) is as close if not closer to the
frequencies the 6300 was putting out, it seemed a natural choice.