Colour Digital Logo on DECwindows Login

-----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk- bounces at classiccmp.org] On Behalf Of Dave McGuire Sent: 28 July 2010 00:06 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Colour Digital Logo on DECwindows Login On 7/27/10 6:09 PM, Rob Jarratt wrote: stuff I'm sorry for how terrible this will sound, but I don't know how else to say it...Where X is concerned, I know my stuff as well, and it really doesn't sound like your friend does. I mean no disrespect either to you or to him by that statement. I have an X11 window directly to the right of the window I'm typing this message in, it's showing colors, and it's being displayed here from another system on the network. I run like this all day, every day. I'm not running Exceed, but a different (current technology) X server, but the concepts and protocol are the same.

Nope. SHM (more properly "MIT-SHM") is only used for images. (XImage objects in particular, and sometimes pixmaps) Background colors or drawn objects don't use SHM. It's used where image transfer speed is important, like video and animations. Nope. I've run color X terminals (which is essentially what you're doing with Exceed) from DEC X implementations, and they work fine. This is where it call came from, after all: DEC was a member of MIT's Project Athena, where X originated. I've never seen anything DEC specific there with the exception of DDX (device-dependent) code and their window manager. The former is almost by definition vendor-specific, and the latter is too, but perhaps less so depending on your point of view. Some background: An X client program (which includes your login window, it's an X client too) initiates a connection to the X server and does a few things, including optionally making a call to XGetVisualInfo() to get the list of "visuals" that the server supports. A "visual" is basically a target display type that specifies the color depth of the display, and might be something like "monochrome", "8-bit greyscale", "8-bit pseudocolor", "true color", etc. Most X servers support many different visuals simultaneously. The X client then selects the visual it wants to use. (a note for the pedantic: yes, I've skipped many Xlib calls and details here for brevity) It's possible that Exceed does not have any color visuals that the login window X client supports or wants to select. Note that I typed "OPTIONALLY makes a call to XGetVisualInfo()" above. It's possible for an X client to just use the "default" visual, and that is server-specific, and usually configurable. On most X servers, the default visual (actually visual "class") is set on the command line when the server is started. I have no idea of how to set the default visual for Exceed. We can drill down a bit further if you'll log into the machine via Exceed, and run "xdpyinfo" and look at the output. Pay attention to the visual names and IDs that it reports as being available. Are there any color visuals present? Also, look at the default visual ID for the first "screen" entry. See if that visual ID is that of a color visual. If it isn't, but if there are in fact color visuals present, it's possible that the login window X client was written to only use the default visual, which may not be a color visual under Exceed, but might be a color visual on the workstation. It's also possible that the login window X client is configurable via its app-defaults file. We can check on that if you strike out with the visuals described above. -Dave -- Dave McGuire Port Charlotte, FL