Thursday, July 10, 2008
Window Beyond a Plateau, Window Into Windows
I recently had reason to use VNC, Virtual Network Computing and then while using GRML, noticed something, a mention of a VNC client, that aroused my curiosity, and made me decide to do some googling on the subject. A search of the Debian packages turned up a couple of 'console' based VNC clients that did not require X. These obviously would need some kind of graphical interface, but in the case of svncviewer and directvnc, these were SVGAlib and framebuffers respectively. Not using a framebuffer on my PC, I installed svncviewer and tried using it. At first it didn't seem to work, but studying the error messages it gave, there was some hint that the graphic modes available for it weren't in line with what the VNC server needed. I was puzzled at first, trying various parameters suggested by the svncviewer man pages, but then remembered that there was a configuration file for SVGAlib, /etc/vga/libvga.config in the case of my Debian computer. I edited this, loosening up everything I could as far as the video went to allow the maximum resolutions suggested by the comments in the file. This worked great, svncviewer began working, connecting to both Linux X desktops and Windows boxes. The act of editing this configuration file jogged my memory that when I'd originally started using SVGAlib on the computer I was using a monitor already long obsolete when I took possesion of it, and had finally gave out and had been replaced with something more reasonably up to date. In other words, updating the SVGAlib settings was long overdue. The most obvious initial problem was that the mouse seemed impossibly difficult to work with on the virtual console used by svncviewer. With adjusting the SVGAlib video settings so fresh in mind, I tinkered with the mouse settings in the config file. Part of the problem was that I'd try to move the mouse slightly and it would jump to the other side of the screen or do other crazy things, only occasionally doing what was desired. This all apparently fell under the description of 'accleration' from what I could figure out from the configuration file notes. Without going into specifics, which will undoubtedly differ from case to case, I found I could adjust the trip point and amount of 'accleration' to make the mouse move smoothly, problem solved. These settings solved problems with applications other than svncviewer, notably the links2 browser. Now the mouse was more usable with it as well, and the higher resolution put more of a web page on the screen at one time. As a test for using this in the real world, there was a MS Window machine I needed to start using, but real world phyisical deskspace is at a premium. I managed to get the machine connected, reasonably close to my personal desktop workstation, and then get a VNC server installed on it. VNC doesn't seem to do anything to link up the audio I/O, only video, keyboard and mouse/pointer, so I connected it to my workstation with some 99 Cents only audio patch cords in addition to putting on the Ethernet LAN. (Anyone know of any 'virtual patchcord' application that could replace these?) On boot up, the VNC connection seemed to start early enough to catch request for a 'Ctl-Alt-Del' entry to get to the graphical login prompt. This I had to reach over and enter from the Windows machine keyboard, but everthing else has seemed to work one way or the other from the svncviewer. Some online documents hinted at possible problems for svncviewer connecting to Windows boxes due to some palete problem, but that doesn't seem to happen with the version I have installed. Using everything involved, I've been able to use the Skype client on the Windows machine to place and recieve calls, and fire up FireFox on it, and set up/handle an account for one of my bills online. There was some mention online of a bootable Linux floppy disk with svncviewer on it, for an ultra-light X desktop, and I've conducted some experiments with setting svncviewer up on a console in /etc/inittab. (This last might require some addition to the autologin script, putting some sleep delay to prevent excessive respawning from inittab triggering a temporary lock on the virtual console if the server it's pointed at isn't immediately available, but seems like a problem that can be dealt with.) At the very worst, svncviewer provides a remote monitor, with occasional need to get the actual keyboard of the machine you connect to. So far I haven't found F8 or any other keyboard combinations to get to any menus or whatever, as was suggested for other VNC viewers, but this can be dealt with. But basicly, it works. It has me thinking about setting up an X/GUI server.