From: wells_s@kosmos.wcc.govt.nz (Steve Wells)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: SM 124 Size adjustment
Date: 27 Jan 1993 21:04:24 GMT
Organization: Wellington City Council (Public Access), Wgtn, Nz
Distribution: world
Reply-To: wells_s@kosmos.wcc.govt.nz
NNTP-Posting-Host: kosmos.wcc.govt.nz

This message is rather largish, but explains in detail how to adjust
your Atari mono' monitor.  I tried it, and it worked fine for over 5
months, before I eventually sold if (I have had little use for it
lately...)


                         HOW TO ENLARGE YOUR
                                SM124
                         MONOCHROME MONITOR'S
                             SCREEN SIZE

                                  by
                            Jack P. Durre'


    If you've used the Atari ST computers with the SM124
monochrome monitor, chances are quite good that you have come to
accept the wide (black or white) border surrounding the usable
area of the screen.  You may have asked "why?", but probably only
grumbled about it, and went back to work.  If you've got the time
(about 15 minutes, on average), the tools (3 or 4, and available
from most Radio Shack stores), and the nerve (very little
required!), this article will explain how you can actually have a
LARGER, usable screen (as compared to the Mac)!

    First, credit where credit is due...The original information
for this modification came from the April, 1986 issue of "ST
APPLICATIONS" magazine, in an article written by Albert Lew.  I am
merely explaining my own methods, following the original steps as
outlined in Mr. Lew's article.

    That said, let's get the caveats out of the way:  While I may
personally consider the following modifications to be simple and
straightforward, I can't write a "Hello World" program in
BASIC!!!  In other words, what may be "simple" for me, may be
quite difficult for you.  If you feel that you are NOT qualified
to make these modifications, DON'T!  Find an able (and willing!)
friend or service technician to do it for you, or forget the whole
idea, and live with what you've got!  If your monitor is in
warranty, opening the case will, obviously, void that, and the
possibility also exists that even if you wind up paying for
repairs, the technician MAY refuse to work on your machine!
(Chances are, however, that he's more likely to want to know more
about making the mods himself!)  Further, the electrical current
coming from the wall plug is enough to knock you silly, or worse,
and inside of the monitor case, it gets even stronger, so be aware
that touching the wrong thing may well put you into an "endless
loop" of your own!  In other words, YOU CAN GET KILLED!  Now, if
you've decided that you'd "kill to have a larger screen", then
follow me!

    Tools:  These are really few in number, and quite simple to
come by.  Mr. Lew suggested some non-TV type of tools, but I'm
going to stick to my guns here, and insist that you use the right
tools for the job!  You'll need a Phillips screwdriver, preferably
a #1 size.  (If you don't know the difference between a Phillips,
and a slotted-head screwdriver, let me stop you right here, and
suggest that you return to your programming!)  You'll also need
two TV "tuning tools"; a hex-tool, 3/32" ("across the flats", as
they say) and a flat-bladed tool, 1/8" or so in blade width.  Both
of these tools should be made of non-conductive (plastic)
material, and longer is better!  A make-up mirror is also quite
handy, particularly a free-standing one.  I might also suggest a
thick towel or other material to protect the face of your monitor
and the top of your desk, during the time that you are moving it
around.  Finally, the toughest item of all...some CLEAR SPACE!
You'll need to move the monitor around a little, and of course, it
will need to be connected to your CPU (and I DON'T recommend
trying to balance it in your lap!), so plan accordingly.

    Next, let's try to orient ourselves, so that you aren't
amputating the screen, while I am talking about the power cord!
The "front" of the monitor is the viewing screen, the "rear" is
where the power cord, and CPU/Monitor connector cable exit the
case.  Since we're going to turn the entire thing around, so that
the screen is facing AWAY from us, "right" will now be the side
where the speaker is located, and "left" obviously (it IS, isn't
it?) will be opposite that, where the control knobs are.  "Top"
will still be in its usual location, and if you haven't already
figured out where the bottom is, it's time for another cup of
coffee!!!

    Ready?  Here we go!

    Boot your system, using either the desktop, with one or more
windows opened, or call up a text file.  The ideal situation is to
have text reaching all four corners of the screen, so that you
will be able to compare from one area to another.

    Now, unplug the monitor's power cord from the socket in the
cabinet, and turn the monitor around, so that the rear of the case
is facing you.  Place the towel or padding on the desktop in front
of the monitor, and tip the entire unit up onto the glass face
(carefully!).  Now, using the Phillips screwdriver, remove the 5
screws holding the cabinet together.  (Two on the bottom, one on
each side, about 3/4s of the way up, and one just above the power
cable socket.)  Once these have been removed, put them somewhere
safely out of the way, and don't worry about mixing them up,
they're all the same size.  Now, gently lift straight upwards on
the rear sides of the case, and it should begin to lift
away...CAREFUL!  You have yet to disconnect the speaker wires, and
there's not too much extra wire here.  See it?  Carefully reach
down to the connector where it joins with the mother board, and
pull it straight away from the board, disconnecting it.  Don't be
too concerned about the orientation of the plug, as it will work
in either direction.  Once you've done this, continue to lift the
rear section of the cabinet away, feeding the CPU/Monitor cable
through the opening as necessary.

    Set the cabinet out of the way (And don't STEP ON IT!), and
proceed with the REAL modifications!  Tip the monitor back down to
its bottom, and arrange the mirror so that you can see the screen
while working at the rear of the unit.  Re-connect the power cord,
and turn on the monitor, being careful to NOT stick your fingers
inside the wrong areas!

    Grab your plastic flat-blade tool, and start looking along the
right side of the mother board (remember now, we're looking from
the rear of the set!).  Near the front of the board, neatly tucked
between the picture tube, or CRT, and a vertical metal
heatsink/power board, is a row of 3 white adjustable controls, or
potentiometers, about 1/2" in diameter, labelled "VLINE", "VSIZE",
and "VHOLD".  We're interested in "VSIZE", which is the middle
control "pot".  (NOW you know why I suggested a long tuning
tool!)  Gently slip the tool into the slotted head of the pot, and
while watching the screen in the mirror (you DID boot up the
system, didn't you?), begin to turn the tool slightly (try not to
apply much pressure to the pot, as that CAN effect the setting).
The top and bottom of the screen will begin to move, together or
apart!  Expand the screen to within approximately 1/2" - 3/4" of
the top and bottom of the "bezel", or plastic frame on the front
of the monitor.  (Too close to the bezel, and you'll find that you
have to be EXACTLY in front of the screen, or miss some of the
information!)

    See?  Feeling more confident already, aren't we?

    Moving right along, we will now swap our tuning tools, opting
for the hex-shaped one.  Looking near the left rear corner of the
mother board, close to the point where the power cord socket is
located, you will find a plastic shaft with a slot in it, sticking
straight up from the board, and just slightly ahead of that, a
strange-looking device, composed of a small-diameter tube, with
what appears to be a couple of "bobbins" of wire on it.  Inside of
that small tube, there is a small, somewhat-fragile core of
graphite, which WILL break, if mistreated, so act accordingly!
Gently lower your hex-tool into this tube, and you will feel it
slide home into the core.  (Again, don't press down on the core.)
By turning this core in a clockwise direction, and watching the
mirror, you will see the screen shrink slightly first, and then
grow WIDER!!!  (Now we're really starting to cook!)  Remember to
leave about 1/2" - 3/4" border, to avoid having the edges hidden
by the bezel.

    What's that you say?  Your picture got larger, but it looks
off-center?  Well, cheer up, bunkie, 'cause we're gonna fix THAT
right now!

    See that big chunk of glass up front?  Well, it has a "neck"
on it, and the back end is pointing directly at us, with some
strange looking electronic stuff along the way.  At the very back
of the tube are some electrical connections, but we're not worried
about them...what we're after are the two magnets that look sorta
like "Q"s around the neck, about 1-2 inches forward of the
connections.  See 'em?  They're dark grey or black, probably, and
have a little "ear" sticking up away from the tube, so that you
can gently push them around until you get the picture centered
on the face of the CRT.  Don't worry about touching THEM...just
try to keep from resting your hands on any "hot" contacts!  This
may take a little time to screw up your courage, but once you get
the hang of it, you'll find it quite easy!  Once you've got the
picture fairly well centered, you may need to go back and
re-adjust the VSIZE or Horizontal size, as all of these things are
interrelated.

    Next, we're gonna make the picture sharp again, in case you're
worried that you've just lost that beautiful screen that you love
so much!

    Remember the slotted plastic shaft at the left rear of the
mother board?  Well, THAT's the "FOCUS" control, and if you'll
again resort to the flat-bladed tuning tool, you can use that
control to find the best compromise for YOUR taste!  Atari chose
to go for a tack-sharp center screen, and let the corners be a
little softer in focus.  You can do the same, or go for sharp
corners and let the center go a little soft, or shoot for some
compromise.  (Hey!  Life's a compromise!)  Once you've done this
step, you can actually turn the set around, and admire your
handiwork!

    If you see some other minor fine-tuning that you want to go
back and do, feel free.  This is now a CUSTOM-TUNED monitor of the
first rank, and you will have even more pride in your ST than
before!

    To reassemble the cabinet, turn off the power, slide the
CPU/Monitor cable through the rear cabinet section, and with your
third hand...yep, gotta remember to reconnect the speaker leads!
There IS a sort of indicator as to which way the plug was
originally connected...One side has two slots, and the other side
has only one, but the speaker WILL work even if this connector is
reversed.  Incidentally, if you want to go one step further, Mr.
Lew suggests the addition of an Audio-OUT connector from this
lead.  Your choice.

    Finally, having reassembled the cabinet, re-connect the
monitor to the CPU, boot the system up, and check out the BIG
PICTURE!!!  If you have any problems, check first, to see that
power is reaching the set, and that the green LED indicator is on.
If not, you may not have reconnected the power cord securely, or
possibly a fuse has blown or been broken (fuses are located on the
vertical power board at the side, near the VSIZE pot, and easily
replaced from Radio Shack).

    Enjoy your "new" monitor, and if you have any questions on
this modification, you can reach me here, on CompuServe, at PPN
75046,476.

    Seeya!  [Jack]



Note:  Only use the proper tools for this job, otherwise you can stuff
the monitor, or turn yourself into Kentucky Fried Atari-user!


  Contrary to popular belief, money IS everything!       |||        
  To cause a catastrophic disaster, you need a computer! ||| TARI   
  If several things can go wrong, the one that will     / | \       
  cause the most damage, happens first!          At least it goes!  
WELLS_S@KOSMOS.WCC.GOVT.NZ