sm124 screen size help req
keith michel
prefer,if there were no borders at all.
I have had the back off and located the h-size variable inductor and the
v-size pot and adjusted both to max size but my screen size is still far
too small for me. are there any hardware fixes or components that I
could change because it looks like a common problem between the vsize
and hsize maybe the gain, but without a drawing im donald ducked.
--
keith michel
Gerry O'Rourke
<ke...@trevis.demon.co.uk> wrote:
A file on this very subject was posted by :-
Frank Vuotto (fvu...@laplaza.taos.nm.us)
TO: Newsgroups: comp.sys.atari.st
Subject: Enlarge the SM124 Screen
Date: 20 Sep 1995 13:55:07 -0600
I have the file, but cannot post it & my external E-mail is down.
Hopefully, this will jog somebody else's memory.
Or, try contacting the poster.
--
Gerry O'Rourke
Materials Engineering
Northern Telecom (Ireland) Ltd
E-mail gig...@nt.com
Jean Marie Bussat
The is some software way to reduce screen border (overscan). It would
be better than trying to made some modification on your SM124.
The horizontal section of a monitor also drive the very high
voltage power supply. So any modification without any information
of some peripheral components (voltage rating on high voltage
capacitors or voltage rating of the CRT) would be _very_ risky.
So you'd better to try overscan.
I haven't got a lot of things about this subject but I'm sure
that there is enough people here which are able to give you more.
Hope this help.
Jean-Marie
+---------------------------------------------------------------+
| Jean-Marie Bussat - Laboratoire d'Annecy-le-vieux de Physique |
| des Particules - BP 110 - 74941 ANNECY-LE-VIEUX - FRANCE |
| Email: bus...@lapp.in2p3.fr |
| Tel: (33) 50 09 17 47 Fax: (33) 50 09 89 13 |
+---------------------------------------------------------------+
It's worth trying to use a misunderstood thing and it
problably wont bring anything good.
keith michel
<bus...@lapp.in2p3.fr> writes
Thanks for your advice jean-marie, but I forgot to mention that it is an
STE that I have and I dont think that overscan works on an STE. However
I could be wrong.
--
keith michel
John Blackwell
K> From: keith michel <ke...@trevis.demon.co.uk>
K> How can I reduce the size of the borders in my sm124. Ideally I would
K> prefer,if there were no borders at all.
K> I have had the back off and located the h-size variable inductor and the
K> v-size pot and adjusted both to max size but my screen size is still far
K> too small for me. are there any hardware fixes or components that I
K> could change because it looks like a common problem between the vsize
K> and hsize maybe the gain, but without a drawing im donald ducked.
K>
Slightly odd that twiddling them hasn't made it big enough, but I
gather that there's a danger scanning it bigger will put even more
stress on a certain coupling capacitor (an under-rated electrolytic)
in the line output circuit.
Said capacitor infamously goes pop, even without overscanning the
picture.
I posted here a bunch of info, kindly passed on to me by various
people, regarding the SM124, and the specific capacitor that it's
advisable to replace. I also have an almost legible .IMG of the
circuit diagram of the beast.
P'raps the best thing would be if I organised these files together,
zipped 'em, and posted them up to 42BBS and Chamelion, in fact, I
will!
If they don't appear there pretty soon, feel free to prod me via
e-mail!
john.bl...@aspects.com
---
* Kivi 1.41a *
Katherine L Ellis
variable resistors in the screen, your screen will die a lot quicker.
That' why atari didn't produce the sm124 with this set up.
If you want a bigger screen, get the 14" or try to modify the screen itself
I know that it's possible. But not just turn the resistors, you'll need extra
Hardware.
I hope someone, did it and reply " No it is not true"
On Thu, 4 Apr 1996, keith michel wrote:
> Date: Thu, 4 APR 1996 13:35:39 +0100
> From: keith michel <ke...@trevis.demon.co.uk>
> Newgroups: comp.sys.atari.st.tech
> Subject: sm124 screen size help req
>
> How can I reduce the size of the borders in my sm124. Ideally I would
> prefer,if there were no borders at all.
> I have had the back off and located the h-size variable inductor and the
> v-size pot and adjusted both to max size but my screen size is still far
> too small for me. are there any hardware fixes or components that I
> could change because it looks like a common problem between the vsize
> and hsize maybe the gain, but without a drawing im donald ducked.
>
>
> --
> keith michel
>
>
Robert Wills
> On Thu, 4 Apr 1996, keith michel wrote:
>
>> How can I reduce the size of the borders in my sm124. Ideally I would
>> prefer,if there were no borders at all.
>> I have had the back off and located the h-size variable inductor and the
>> v-size pot and adjusted both to max size but my screen size is still far
>> too small for me. are there any hardware fixes or components that I
>> could change because it looks like a common problem between the vsize
>> and hsize maybe the gain, but without a drawing im donald ducked.
There are five or six adjustments you can do inside an SM124. You CAN
eliminate the black border, but you run a risk of overstressing some
resistors, and besides, it doesn't look very good that way! The outer
edges will be "around the corner", and the focus, which is always a
compromise between centre sharp and edge sharp, will be that much more
difficult to compromise! I keep my monitor(s) tweaked just a bit tall
(things look better to me that way), but when I do desktop publishing, I
have to remember to stretch picture files extra tall, to have them look
right on printout.
--
Songshop Musical Productions / "This country used to run
Box 266, Shawville, Quebec / on horsepower and steam.
J0X 2Y0 (819) 647-6022 / Now it runs on bullshit and hot air."
Jim DeClercq
: > On Thu, 4 Apr 1996, keith michel wrote:
: >
: >> How can I reduce the size of the borders in my sm124. Ideally I would
: >> prefer,if there were no borders at all.
I had (new TT, Atari warehouse clearance) my ST monitor stretched as far
as it could go, which was not all the way to the edges, and never did get
screen linearity exactly right, and have it stay that way. I do not know
if it can be done. Circles came out egg-shaped.
I have spent a lot of time inside those things. Personally, I am not
concerned about overstressing anything. Nothing runs warmer, to my
touch, with the screen stretched. If you are not used to working on
monitors, use somebody else's fingers for this. The flyback resonating
capacitor fails not due to stress, but due to being positioned next to
the heat sink for the horizontal output transistor, which gets hot and
bakes it. I moved it.
That capacitor position is horribly bad design practice, particulary for
a monitor that started out in life as an NCR bank machine monitor. Atari
was not the first to use this monitor. Thus, if the tube quits, it can
be re-gunned with a gun for an NCR bank machine, which did not get all
used up before NCR switched to color monitors. NCR knows nothing about
this. CRT rebuilders know about this.
---------------------------------------------------_--------------------------
jimd1 __ __ ____ ___ ___ ____
ji...@primenet.com /__)/__) / / / / /_ /\ / /_ /
/ / \ / / / / /__ / \/ /___ /
mike kinzie
>
> > On Thu, 4 Apr 1996, keith michel wrote:
> >
> >> How can I reduce the size of the borders in my sm124. Ideally I would
> >> prefer,if there were no borders at all.
> >> v-size pot and adjusted both to max size but my screen size is still far
> >> too small for me. are there any hardware fixes or components that I
> >> could change because it looks like a common problem between the vsize
> >> and hsize maybe the gain, but without a drawing im donald ducked.
>
> There are five or six adjustments you can do inside an SM124. You CAN
> eliminate the black border, but you run a risk of overstressing some
> resistors, and besides, it doesn't look very good that way! The outer
> edges will be "around the corner", and the focus, which is always a
> compromise between centre sharp and edge sharp, will be that much more
> difficult to compromise! I keep my monitor(s) tweaked just a bit tall
> (things look better to me that way), but when I do desktop publishing, I
> have to remember to stretch picture files extra tall, to have them look
> right on printout.
>
> --
> Songshop Musical Productions / "This country used to run
> Box 266, Shawville, Quebec / on horsepower and steam.
> J0X 2Y0 (819) 647-6022 / Now it runs on bullshit and hot air.
hello, maybe you can help me. I have a 1040 st and my Sm125 monitor just
gave up. I found a pcm 124 Atari Monitor used but it has a different
connector on it ( 9 pin PC type) rather than my round one. There are not
too many people here in Vancouver who know much about Atari anymore. Can
you tell me if this one will work with my st.
Thanx
Mike Kinzie
FLORIAN WILCKE
KELLIS wrote:
> Hi, I would like to do that , but I heard a lot , that after touching the
> variable resistors in the screen, your screen will die a lot quicker.
[...]
> I know that it's possible. But not just turn the resistors, you'll need extra
> Hardware.
> I hope someone, did it and reply " No it is not true"
Sure, here's one ...
I did it shortly after I bought my ST (turning the H/V pots /
inductors). I think, it was back in '88. I have almost a full size
picture. About 1cm to each "H"-border and 1.5 cm in the V-axis.
The only thing I discovered was, that the pixels on the outer area
are a litlle more "defocussed", especially in the edges.
Why, do you think, it's "going to die" faster ?
Florian
-------
Florian Wilcke EMAIL: fl...@stingbox.sb.sub.de
13507 Berlin (Tegel) Fax: +49 30 3031 5369
Michael Schwingen
Florian Wilcke (fl...@stingbox.sb.sub.de) wrote:
FW>Why, do you think, it's "going to die" faster ?
I have seen multiple dead SM124's (of the new series with switching PSU)
where the owner used the 'B+' pot to increase the horiz. screen size - they
usually die after 10 min.s to 1 hour with that adjustment, depending on how
much they turned up the voltage.
If you do it the right way, there is a little more stress on some
components than before, but this does not usually lead to rapid failures.
cu
Michael
--
Michael Schwingen - Ahornstraße 36 - 52074 Aachen - Germany
Home: rinc...@discworld.oche.de Maus: Michael Schwingen@AC3 IRC: Rincewind
Univ.: mich...@pool.informatik.rwth-aachen.de <--- use this for mails >100K
Rich Tietjens
76702...@CompuServe.COM barked in U.COMP.SYS.ATARI.ST.TECH on 27 Apr
1996:
> As for damaging the monitor, I think that part is a myth. I've known
> lots of people who changed the size of the picture and never had
problems,
> and at the same time, lots of people who left theirs alone and had their
> monitors die. I modified my SM124 in 1986 to fill almost the entire
> visible area on the screen, and it's been running great since then.
No, that's true, Bob. When you increase the screen size, you increase both
the voltage that must be handled by the one capacitor that's least able to
handle it (the one that eventually leaks black goo) and the bandwidth that
the video ciruitry must handle. Bandwidth is directly related to power
consumption, and power to heat. And we are all aware that heat reduces the
life of eletronic components. For semiconductors (i.e., transistors,
diode, and so forth), it's not very important whether they last 300 years
or only 250, but capacitors and resistors have a shorter lifespan to begin,
and the "weak" electrolytic that Goldstar used in the SM124 is already
exceeding its "normal" lifespan by now, if you have an early Goldstar circa
1984-85.
--