(Please read the DISCLAIMER at the bottom of this document before proceeding) BTW, if you use a fixed-frequency monitor, there is a trick that seems to be almost unknown that will allow you to use lower resolutions - this is great for full-screen DOS boxes or Direct X games. Maybe you'd like to include this on your page. The trick is to increase the front porch and back porch times, reducing the signal times thereby - this will leave the original frequencies, so the monitor stays in sync. For instance, if you want to use the SGI monitor above in a 640x480 mode: We want to use 640 pixels instead of 1280 horizontally, so set the first number to 640. This drops 640 pixels, divide that by 2, giving 320. Subtract this 320 from the 2nd and 3rd value, giving 992 and 1096, respectively. Vertically, we want to use 480. Set the first number to this, and then subtract (1024-480)/2=272 from the 2nd and 3rd value: The resulting ModeLine is: ModeLine "640x480" 128 640 992 1096 1664 480 755 758 1064 +hsync -vsync To do the same in Windows with a Matrox, edit the mga.mon file - it's even easier with this. Pick an entry that works - for the above example, one would look like this (the comments are added by me and should NOT occur in the mga.mon file): [User-Defined.SGI] 1280x1024 = NI, *User-Defined_SGI_,(1280x1024) [*User-Defined_SGI_,(1280x1024)] PIXEL_CLK=128 H_DISP = 1280 H_FPORCH = 32 # =1312-1280 H_SYNC = 104 # =1416-1312 H_BPORCH = 248 # =1664-1416 H_SYNC_POL = 1 # +hsync V_DISP = 1024 V_FPORCH = 3 # =1027-1024 V_SYNC = 3 # =1030-1027 V_BPORCH = 34 # =1064-1030 V_SYNC_POL = 0 # -vsync Now, create a similar entry in the [User-Defined.SGI] section, and a new section for the 640x480 resolution: [User-Defined.SGI] 640x480 = NI, *User-Defined_SGI_,(640x480) [*User-Defined_SGI_,(640x480)] PIXEL_CLK=128 H_DISP = 640 H_FPORCH = 352 # =1312-1280+(1280-640)/2 = 992-640 H_SYNC = 104 # =1416-1312 = 1096-992 H_BPORCH = 568 # =1664-1416+(1280-640)/2 = 1664-1096 H_SYNC_POL = 1 # +hsync V_DISP = 480 V_FPORCH = 275 # =1027-1024+(1024-480)/2 = 755-480 V_SYNC = 3 # =1030-1027 = 758-755 V_BPORCH = 306 # =1064-1030+(1024-480)/2 = 1064-758 V_SYNC_POL = 0 # -vsync The only thing that's important is that the sum of H_DISP+H_FPORCH+H_SYNC+H_BPORCH is the same as the original, as well as the sum of V_DISP+V_FPORCH+V_SYNC+V_BPORCH. In the first try, i wouldn't change H_SYNC or V_SYNC. With that, you should get a reduced-size, centered image - the FPORCH and BPORCH values give thick black margins. To center the image, you might want to change FPORCH and BPORCH - subtract from BPORCH what you add to FPORCH and vice versa, and be aware that FPORCH is the size of the lower/right margin and BPORCH the size of the upper/left margin. If you want to increase the image's size, it could help to reduce the PORCH values and increase SYNC - but do this SLOWLY! (To do this on a windows system, i'd use the Matrox Display Utility after creating an initial entry. For Linux, you might want to use xvidtune, although i personally prefer starting xdm, logging in through the net, then changing my XF86Config file over the net and pressing alt-ctrl-BS on the server until it works fine). DISCLAIMER: We (Mike Frisch and the source of the information, Guntram Blohm) will not be held responsible for damage caused by misuse of the following information. Use at own risk! If your monitor blows up because of this, you were warned! Source: Guntram Blohm