From: Ray Byrne <ray@in4media.co.uk>

Date: September 3, 2009 2:58:48 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: Multiple display support


Hi Mark,


I do wonder sometimes why you have a penchant for making everything complicated? I've learnt over many years to try to overcome the many complications that are inherent in astronomy by simplifying things. My set-up is this: Celestron C9.25 (known to be a good planetary performer with Bob's Knobs for collimation) EQ6 mount (relatively inexpensive EQ mount known to offer good tracking), an observatory dome (best investment yet as I can be up and running in moments and off to bed just as quickly), TIS 21AFO4 camera, Filter wheel with Astronomics LRGB filters + IR Pass filter, Apple Macbook (3 month's old) and of course Astro_IIDC. 


With this set-up I still have the complications of poor seeing, and with Jupiter in the northern hemisphere low altitude, and I still have to learn by practice and experience how to use the software in different situations and all that's involved in post processing (like assembling my LRGB components into a colour image successfully). If I burdened myself with all the issues you seem to with long cables, dual monitors, working off concrete slabs that hold heat in and radiate it all night and a host of other stuff I'd get nowhere... I'm nowhere near what I'd like to be and I think I've cut-out a lot of the crap.


What I'm trying to say mate is keep it simple. Focus on what you want to do - is it Lunar and Planetary, is it deepsky (a whole different and expensive ball game and in my mind one that is well trodden by others so what's the point). There are so many things waiting to bite you up the bum in this frustrating but fascinating hobby why add to them.


ATB


Ray



On 3 Sep 2009, at 20:11, Mark Gaffney wrote:

Hi Milton & others, 

I don`t know if it`s quite the same thing but I run 2 VGA screens from my Mac Mini G4 (& latest version of Astro IIDC) They`re only 19 " screens but I could go bigger if I could afford it. I`m doing this with a VGA splitter & a DVI-VGA connector (one of which came with the Mac Mini) & a male/female VGA cable to the splitter. It`s a Lindy model from here in Australia & there is a 4 port job. I used to run 2 DVI monitors through a DVI splitter &/ or a DVI /VGA KVM switch. (That`s another story...) I think the DVI splitter still works by itself but my original DVI Samsung monitor has "gone to sleep"- won`t start when wanted. I have another more recent Samsung 19 " monitor which is inclined to do the same if I ever need to restart the computer (which is quite frequently). I usually leave this one on permanently. My other Asus 19" monitor can be switched on & off at will. I `ve had a "gold" 15 metre VGA cable for quite a while which I was using to have one monitor at the computer & one out at the scope but since that distance has lengthened I`ve recently bought a 20 metre VGA cable (not gold this one-for about $80 Australian dollars) & am waiting on postage of an iBook G4 as well. I think the VGA splitter was about $80 -$100 worth. For multiple working areas on either screen (up to six) I use "Spaces" which came with Leopard. I almost forgot- I also have a usb hub or three & run a 2nd Apple keyboard to the 2nd monitor! 


Mark.

On 04/09/2009, at 1:31 AM, Milton Aupperle wrote:

Hi Malte;


On 3-Sep-09, at 6:21 AM, maltetewes wrote:


What I did is to turn off display-mirroring, put AstroIIDC's preview window on the beamer while keeping the control window on the laptop screen, hiding the dock, and setting the beamer to a very low resolution (... 640 x 480, thus keeping the AstroIIDC zoom at 100%). Well I still had that menubar on the beamer, but otherwise it was perfect. (actually I even used multiple desktops to switch between a moon chart and live view etc... plus you can get a black menubar by using the negative-image setting in the system prefs.

Extemely important here is the framerate : I experienced that I couldn't get a fast live view using AstroIIDC's own zoom and keeping the beamer's resolution at native value. And for such presentations, all the pleasure really comes from the faster-then-turbulence framerate...


Just so you know, the Zoom is done using Apple's "Core Graphics". It's anywhere from 30% to 100% slower than using the 25 year old "QuickDraw" copybits calls for blitting images, and the performance hit varies depending on size. I've bench marked this for both Intel and PowerPC for Panther Tiger and Leopard. Going to OpenGL (or possibly OpenCL in Snow Leopard) would improve things, but that has issue or works erratically with multiple displays depending on what Graphics Card you have (model, Ram, GPU and manufacturer all make a huge difference).


Secondly, if your using a version earlier than 4.0x of Astro IIDC with Leopard or earlier and also have Astro IIDC drawing text on the screen (i.e. sharpness numbers etc.), that triggers another major CPU hog in Core Graphics. Drawing a single letter on screen (like the letter  "A")  on screen at 30 fps was using up 40% of the CPU under Tiger or Panther. That has dropped to 8% in Leopard, however I stopped using Core Graphics for text drawing and went back to 10+ year old ATSUI text drawing method which uses about 3% cpu usage to draw any text, not just a letter. Going back to 25+ year old QuickDraw for text drawing and the CPU usage difference isn't even measurable no matter what I draw.


<RANT_TIME>

It still irks the crap out of me that multiple displays are done so poorly in OS X, where as in OS 7 to 9 back in the late 80's /  early 90's  with hardware that had 1/10 the CPU power and 1/100th of the GPU power, I could easily run 3 monitors on a single core 20 mhz 680xx Quadra when doing GIS demos at large oil conventions. Using QucikDraw3D's  (now Steve'd) retained mode, I was creating 3D models with textures and lighting, then saving them to disk and then letting people play with them in the simple QD3D viewer, which made the Silicon Graphics Guys cringe cause they were selling boxes that cost $250,000 plus and could not do this as easily.

</RANT_TIME>


Milton J. Aupperle