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- The modes provided with TWEAK range from the obscure to the useful.
- This file has some hints and some vital information.
-
- First of all, a small warning:
-
- All mode files with an 's' at the and of the name (for example
- 800x600s.16) use special dot clocks available on my Chips &
- Technologies 80c451 SVGA card. Feel free to try them on your card, but
- don't expect them to work on a vanilla VGA.
-
- Modes with a 'c' at the end of the name are chained modes, to
- distinguish them from unchained modes of the same resolution.
-
- Then, some info about modes of particular interest:
-
- 256x256c.256 - The chained Mode Q:
- o 256x256 in 256 colors
- o exactly 1 page, uses every single byte of the video segment
- o 1-to-1 linear pixel-to-address mapping, like mode 13h
- o keep (x,y) coordinates in a single word, and use that word as
- an offset. (Both x and y fit in a byte!) No more MULs!
- o I named it 'Mode Q' for 256-cubed (256x256x256 = 256^3).
-
- 256x256.256 - The unchained Mode Q:
- o 256x256 in 256 colors
- o exactly 4 pages
- o 4-to-1 planar mapping, like Mode X
-
- The 256-column modes have been provided in several other vertical
- resolutions: 224 and 240 lines
-
- 400x600.256 - new, more stable version
- o 400x600 in 256 colors (unchained)
- o 1 page + 22144 bytes (55.36 lines)
- o 4-to-1 planar mapping
- o good multisync monitor is still required
-
- 400x300.256 - New square aspect ratio mode
- o 400x300 in 256 colors (unchained)
- o That means a square aspect ratio if stretched to fill the screen!
- o 2 pages + 22144 bytes (55.36 lines)
- o 4-to-1 planar mapping
- o NOT based on the above 400x600 mode! Uses the lowest vertical
- frequency, and should thus prove much more stable than the
- 600-line mode.
-
- 360x360.256
- o Interesting mode, which should work on most VGAs.
-
- 360x270.256
- o New square aspect ratio mode
-
-
- Known problems:
- ---------------
- o The 400x-modes won't work on LCDs and similar equipment
-
- o They also fail (won't synchronize) on cheap, basic VGA monitors
- like the Samsung I used to have. I think your monitor must
- support SVGA resolutions of 800x600x16 and up for the 400x-modes
- to work. Your card can probably be plain, vanilla VGA though!
-
- o Don't expect the modes to line up perfectly with your monitor
- screen's edges! You might have to adjust the size and position of
- the image with your monitor's control knobs.
-
- I have yet to see a VGA setup which doesn't support Mode Q. Let me
- know if you have trouble.
-
-
- Disclaimer:
- -----------
- I can't guarantee that any of the above modes will be compatible with
- your VGA card. I will accept no responsibility for damages arising
- from the use or abuse of the files included in this archive.
-
- If any of the above modes don't work on your configuration, send me
- an email stating the name/chipset of your (S)VGA card, and monitor
- type. I'm especially interested in any changes you could make to get
- them to work! Also mail me comments and suggestions to the TWEAK
- archive. I will probably release a new version by the end of the
- summer. Current ideas include:
-
- o A tutorial on tweaking in general, with focus on unchained, 256
- color modes. I ought to explain the significance of all timing
- registers, and their relevance for the resulting resolution.
- o A program which takes as input a description of a screen mode
- (i.e. resolution, colors) and outputs a list of suggested
- registers settings.
- o A method of linking TWEAKed 256-color modes to Themie Gouthas' XLIB.
- o Context sensitive help on most registers and their individual bits
- within the TWEAK utility.
- o Support for assembler and Pascal output.
-
-
- Regards from
- Robert Schmidt of Ztiff Zox Softwear, Norway
-
- e-mail: robert@stud.unit.no
-