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Re: Hardware Maint. on Time&Materials?
Date: Wed, 24 Jan 90 15:26 PST
From: TYSON@Warbucks.AI.SRI.COM (Mabry Tyson)
Date: Wed, 24 Jan 90 13:26 EST
From: barmar@Think.COM (Barry Margolin)
Date: 24 Jan 90 10:33:50 GMT
From: email@example.com (Eric A. Raymond)
SO how does one adjust a console when the image is offset or scaled
Open it up, and on the deflection board there are a bunch of pots. On
Philips consoles they can be adjusted by hand pretty easily, as they
have plastic thumbwheels. On Moniterms you need a tiny screwdriver.
There's a sticker on the tube that says what each pot is for, e.g.
VERTICAL CENTERING adjusts the vertical offset. It's just a little more
complicated than adjusting a 60's vintage TV.
Remember you are near high voltages and can get fried if you slip. If you
want to do this by yourself and you have never done it before, find someone
who has to show you what to do. DO NOT USE METAL SCREWDRIVERS OR HEX WRENCHES.
Metal screwdrivers are OK as long as you remember this electrician's rule of
ALWAYS KEEP ONE HAND IN YOUR POCKET!!
(Ok, I admit I once tried to tweak the center core of the horiz. size
transformer with a hex wrench when I couldn't find my plastic adjustment
tool. In about 2 seconds in got too hot to handle.)
This is a big mistake. Not only does the metal hex wrench interact with the
gizmo you're adjusting, as you point out the wrench is "induction heated" by
the horizontal scan signal.
While we are on this subject, can someone from Symbolics tell me why it was
decided to have different sized (pixel-size) consoles when they all have a
wide range of adjustment to adjust a specific (say 1250x760) size to fill
the screen. There are all sorts of little things this impacts upon (like
losing a mouse-sensitive item on a particular frame until I hit Function
Refresh after booting on a machine with a different size screen).
The main reason was that even at the Philips sync frequency, the original
Philips monitors were already being run beyond their limits. Using Moniterm
(or G-80) sync on a Philips monitor is guaranteed to shorten the monitor's
life. As you point out, any of the more recent monitors can be adjusted to
fit the Philips screen.
Note that the DIP switch inside the console controls the monitor type that the
console reports to the processor at power-up (or Fep reset) time. If you're
so inclined, playing with switches 1, 2, and 3 of this DIP switch can help
your machine come up with the right sync the first time. (This only applies
to console firmware V16 and later, if I remember correctly.) Perhaps Doug
Evans will grace us with the correct settings for these switches...