Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!uvm-gen!pegram
From: pegram@uvm-gen.UUCP (pegram r)
Newsgroups: comp.sys.atari.st
Subject: Re: overscan - multisync monitors
Message-ID: <1380@uvm-gen.UUCP>
Date: 15 Jan 90 16:33:16 GMT
References: <10636@stag.math.lsa.umich.edu>
Sender: nobody@uvm-gen.UUCP
Organization: EMBA Computer Facility, Univ. of Vermont, Burlington.
Lines: 70

From article <10636@stag.math.lsa.umich.edu>, by hyc@math.lsa.umich.edu (Howard Chu):
> In article <32896@iuvax.cs.indiana.edu> pwp@iuvax.cs.indiana.edu (Paul Purdom) writes:
>>Could someone say briefly what techniques the overscan software uses to do
>>overscanning?

Thanks for the (deleted) explanation. 

> No problem, 8 pixels per byte. With overscan, you need 100 bytes per line, 
> but you won't see 800 pixels on an SM124.  You could with a multisync 
> monitor, but not otherwise. So, you need to be careful, and some programs 
> don't seem to take things into account very well.]  This all seems quite 
> tedious, since programs are supposed to let GEM worry about the nitty-gritty
> details of exact screen size. Some do, and they work fine. Unix Windows is 
> a slick example of one that does. Others run into problems...

More text deleted so the #@&$*#$!@! "mailer" will accept this...
 
> -=- PrayerMail: Send 100Mbits to holyghost@father.son[127.0.0.1] >
and You Too can have a Personal Electronic Relationship with God!

This post brings up some questions that I've been wondering about for a while.

	1) Is the "overscan mod" the one I have the hardware docs for
	   (it was reposted in Nov or Dec '89) that also needs a small 
	   transistor installed, along with a debounced switch, some wire 
	   and some trace cutting?  If not, how many such mods are
	   there and  how do they rank?   I know that overscan can be
	   done in software (I've seen the Care Bears demo - impressive),
	   does that only work well if the program running knows about it?

	2) Would things be simpler and/or even higher resolution with
	   a multisync monitor? (I guess I'm asking what the hardware
	   limits are, for the ST and for the monitors to track the video).

	3) Could a "transparent" interface be written, (see posting by
	   David Beckenmeyer on multiple 80x25 windows on Moniterm while
	   running vsh) that could automate high res to overscan
	   switching?  I envision a program that can't take overscan 
	   being automatically run in a "Std" resolution window, 
	   centered on the screen, and good programs being able to 
	   immediately take over the whole screen when they run.

	4) There are several adaptors and lots of multisync monitors
	   about, how well do they work?  How weird is color on a greyscale
	   monitor?  How is High res (or overscan) on various color
	   monitors - for that matter, how is it on a greyscale
	   monitor?  If dot pitch (on color monitors) is the only criteria 
	   for "mono" res sharpness, what dot pitch is acceptable?  
	  Email me your experiences or responses, and I will post a 
	  summary to the net.  

	5) People with overscan and/or Moniterm or other large monitors,
	   send me (or post) lists of programs which work and of the ones 
	   that break with the extra pixels. I'll post a summary of
	   that too, if there is enough response.

	6) Atari folk: will the TT color monitor be significantly
	   incompatible with third party multisyncs? (I recall it took
	   quite a while before third party monitors showed up for the ST).
	   For that matter, will my old monitor(s) work with a TT?
	  (That would also answer the above question, I think).


Thanks in advance, sorry this got so big.

Bob Pegram (pegram@griffin.uvm.edu) 

 WARNING, I am not certain that above address is correct, since they've
been monkeying with our local net here and retired Uvm-gen. See your
header for a better address.