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svgalib(7)		      Svgalib User Manual		    svgalib(7)

       svgalib - a low level graphics library for linux

       0. Introduction
       1. Installation
       2. How to use svgalib
       3. Description of svgalib functions
       4. Overview of supported SVGA chipsets and modes
       5. Detailed comments on certain device drivers
       6. Goals
       7. References (location of latest version, apps etc.)
       8. Known bugs

       This  is	 a  low	 level graphics library for Linux, originally based on
       VGAlib 1.2 by Tommy Frandsen. VGAlib supported a number of standard VGA
       graphics	 modes,	 as  well  as  Tseng  ET4000 high resolution 256-color
       modes. As of now, support for many more chipsets has  been  added.  See
       section 4 Overview of supported SVGA chipsets and modes

       It  supports  transparent  virtual  console switching, that is, you can
       switch consoles to and from  text  and  graphics	 mode  consoles	 using
       alt-[function  key].  Also,  svgalib corrects most of VGAlib's textmode
       corruption behaviour by catching SIGSEGV,  SIGFPE,  SIGILL,  and	 other
       fatal  signals  and ensuring that a program is running in the currently
       visible virtual console before setting a graphics mode.

       Note right here that SIGUSR1 and SIGUSR2 are  used  to  manage  console
       switching  internally  in  svgalib.   You can not use them in your pro‐
       grams. If your program needs to use one of those signals,  svgalib  can
       be compiled to use other signals, by editing libvga.h

       This  version  includes	code to hunt for a free virtual console on its
       own in case you are not starting the program from one (but instead over
       a  network or modem login, from within screen(1) or an xterm(1)).  Pro‐
       vided there is a free console, this succeeds if you are root or if  the
       svgalib	calling	 user own the current console. This is to avoid people
       not using the console being able to fiddle with it.  On	graceful  exit
       the  program  returns to the console from which it was started.	Other‐
       wise it remains in text mode at the VC which svgalib allocated to allow
       you  to	see any error messages. In any case, any I/O the svgalib makes
       in text mode (after calling vga_init(3)) will also take place  at  this
       new console.

       Alas,  some games misuse their suid root privilege and run as full root
       process. svgalib cannot detect this and allows Joe Blow User to open  a
       new  VC	on  the console. If this annoys you, ROOT_VC_SHORTCUT in Make‐
       file.cfg allows you to disable allocating a new	VC  for	 root  (except
       when he owns the current console) when you compile svgalib. This is the

       When the library is used by a program at run-time, first the chipset is
       detected and the appropriate driver is used. This means that a graphics
       program will work on any card that is supported by svgalib, if the mode
       it  uses	 is supported by the chipset driver for that card. The library
       is upwardly compatible with VGAlib.

       The set of drawing functions provided  by  svgalib  itself  is  limited
       (unchanged  from	 VGAlib) and unoptimized; you can however use vga_set‐
       page(3) and vga_getgraphmem(3) (which points  to	 the  64K  VGA	frame‐
       buffer)	in a program or graphics library.  A fast external framebuffer
       graphics library for linear and banked 1, 2, 3 and 4  bytes  per	 pixel
       modes is included (it also indirectly supports planar VGA modes). It is
       documented in vgagl(7).

       One obvious application of the library is a picture viewer. Several are
       available,  along  with animation viewers. See the 7. References at the
       end of this document.

       I have added a simple VGA textmode font restoration  utility  (restore‐
       font(1))	 which	may help if you suffer from XFree86 textmode font cor‐
       ruption. It can also be used to change the textmode font. It comes with
       some other textmode utilities: restoretextmode(1) (which saves/restores
       textmode registers), restorepalette(1), and the script textmode(1).  If
       you  run	 the  savetextmode(1)  script  to save textmode information to
       /tmp, you'll be able to restore textmode	 by  running  the  textmode(1)

       Installation  is	 easy in general but there are many options and things
       you should keep in mind. This document however assumes that svgalib  is
       already installed.

       If  you need information on installation see 0-INSTALL which comes with
       the svgalib distribution.

       However, even after installation of the library you might need to  con‐
       figure svgalib using the file /etc/vga/libvga.config.  Checkout section
       4 Overview of supported SVGA chipsets and  modes	 and  libvga.config(5)
       for information.

       For  basic  svgalib  usage  (no	mouse,	no  raw keyboard) add #include
       <vga.h> at the beginning your program.  Use vga_init(3) as  your	 first
       svgalib call. This will give up root privileges right after initializa‐
       tion, making setuid-root binaries relatively safe.

       The function  vga_getdefaultmode(3)  checks  the	 environment  variable
       SVGALIB_DEFAULT_MODE  for a default mode, and returns the corresponding
       mode number. The environment string can either be a mode	 number	 or  a
       mode  name as in (G640x480x2, G640x480x16, G640x480x256 , G640x480x32K,
       G640x480x64K, G640x480x16M).  As an example, to set the default	graph‐
       ics mode to 640x480, 256 colors, use:

       export SVGALIB_DEFAULT_MODE=G640x480x256

       on  the bash(1) command line. If a program needs just a linear VGA/SVGA
       resolution (as required by vgagl(7)), only modes where bytesperpixel in
       the vga_modeinfo structure returned by vga_getmodeinfo(3) is greater or
       equal to 1 should be accepted (this is 0 for tweaked  planar  256-color
       VGA modes).

       Use  vga_setmode(graphicsmode)  to  set	a  graphics mode. Use vga_set‐
       mode(TEXT) to restore textmode before program exit.

       Programs that use svgalib must #include<vga.h>; if they	also  use  the
       external	 graphics  library  vgagl(7), you must also #include<vgagl.h>.
       Linking must be done with -lvga (and -lvgagl before -lvga, if  vgagl(7)
       is  used).  You	can  save  binary space by removing the unused chipset
       drivers in Makefile.cfg if you only use specific chipsets. However this
       reduces	the  flexibility  of svgalib and has a significant effect only
       when you use the static libraries. You should  better  use  the	shared
       libraries and these will load only the really used parts anyway.

       Functions  in  the  vgagl(7)  library  have the prefix gl_.  Please see
       vgagl(7) for details.

       There are demos with sources available which will also help to get  you
       started,	 in  recomended	 order	of  interest:  vgatest(6), keytest(6),
       mousetest(6),  eventtest(6),  forktest(6),  bg_test(6),	scrolltest(6),
       speedtest(6),  fun(6),  spin(6),	 testlinear(6), lineart(6), testgl(6),
       accel(6), testaccel(6), plane(6), and wrapdemo(6).

       Debugging your programs will turn out to be rather  difficult,  because
       the svgalib application can not restore textmode when it returns to the

       Happy are the users with a serial terminal, X-station, or  another  way
       to log into the machine from network. These can use

       textmode </dev/ttyN

       on the console where the program runs and continue.

       However,	 the  vga_flip(3) function allows you to switch to textmode by
       entering a call to it blindly into  your	 debugger  when	 your  program
       stops  in  graphics  mode.   vga_flip(3) is not very robust though. You
       shall not call it when svgalib is not yet initialized or in textmode.

       Before continuing your program, you must then call vga_flip(3) again to
       return  to  graphics  mode.  If	the  program  will not make any screen
       accesses or svgalib calls before it returns to the  debugger,  you  can
       omit that, of course.

       This  will  only	 work if your program and the debugger run in the same
       virtual linux console.

       Each function has it's own section 3 manual page. For a list  of	 vgagl
       functions see vgagl(7).

	      - initialize svgalib library.
	      - makes svgalib not emit any startup messages.
	      - declare the amount of video memory used.
	      - start a parallel process to restore the console at a crash.
	      - force chipset.
	      - force chipset and optional parameters.

   Inquire hardware configuration
	      - returns the mouse type configured.
	      - returns the current SVGA chipset.
	      - returns the monitor type configured.

   Setting video modes
	      - sets a video mode.
	      - set the display start address.
	      - set the logical scanline width.
	      - switch to linear addressing mode.
	      - try to set Mode X-like memory organization .
	      - set and query several extended features.
       vga_screenoff(3), vga_screenon(3)
	      - turn generation of the video signal on or off.

   Get video mode information
       vga_getxdim(3), vga_getydim(3), vga_getcolors(3)
	      - return the current screen resolution.
	      - return the color white in the current screen resolution.
	      - returns the current video mode.
	      - returns if a video mode is supported.
	      - returns pointer to mode information structure for a mode.
	      - returns the default graphics mode number.
	      - returns the last video mode number.
	      - return a name for the given video mode.
	      - return a number for the given video mode.

   Drawing primitives
	      - clear the screen.
	      - set the current color.
	      - set the current color.
	      - set the current color.
	      - draw a pixel on the screen.
	      - draw a horizontal line of pixels.
	      - draw a horizontal line of pixels.
	      - draw a line on the screen.
	      - get a pixels value from the screen.
	      - get a list of consecutive pixel values.
	      - wait for vertical retrace.

   Basic (non raw) keyboard I/O
	      - wait for a key.
	      - read a character from the keyboard without waiting.
	      - wait for various I/O events.

   Direct VGA memory access
	      - set the 64K SVGA page number.
	      - set the 64K SVGA page number.
	      - set the 64K SVGA page number.
	      - returns the address of the VGA memory.
	      - copy linear pixmap into Mode X video memory.
	      - copy linear pixmap into VGA 16 color mode video memory.
	      -	 copy  linear pixmap to some planes of VGA 16 color mode video

   Manage color lookup tables
	      - set a color in the color lookup table.
	      - get a color in the color lookup table.
	      - sets colors in the color lookup table.
	      - gets colors from the color lookup table.

   Mouse handling
	      - enable mouse support.
       mouse_init(3), mouse_init_return_fd(3)
	      - specifically initialize a mouse.
	      - explicitly close a mouse.
	      - updates the mouse state.
	      - wait for an mouse update.
	      - sets a mouse scale factor.
	      - set what happens at the mouse boundaries.
       mouse_setxrange(3), mouse_setyrange(3)
	      - define the boundaries for the mouse cursor.
       mouse_getx(3), mouse_gety(3), mouse_getbutton(3)
	      - query the mouse state.
	      - set the current mouse position.
       mouse_getposition_6d(3), mouse_setposition_6d(3), mouse_setrange_6d(3)
	      - provide an interface to 3d mice.
       mouse_seteventhandler(3), mouse_setdefaulteventhandler(3)
	      - set a mouse event handler.

   Raw keyboard handling
       keyboard_init(3), keyboard_init_return_fd(3)
	      - initialize the keyboard to raw mode.
	      - return the keyboard to normal operation from raw mode.
       keyboard_update(3), keyboard_waitforupdate(3)
	      - process raw keyboard events.
	      - modify scancode mappings in raw keyboard mode.
	      - check if a key is pressed when in raw keyboard mode.
	      - get a pointer to a buffer holding the state of all keys in raw
	      keyboard mode.
	      - reset the state of all keys when in raw keyboard mode.
       keyboard_seteventhandler(3), keyboard_setdefaulteventhandler(3)
	      - define an event handler for keyboard events in raw mode.

   Joystick handling
	      - initialize and calibrate joysticks.
	      - close a joystick device.
	      - query and process joystick state changes.
       joystick_sethandler(3), joystick_setdefaulthandler(3)
	      - define own joystick even handler.
       joystick_getnumaxes(3), joystick_getnumbuttons(3)
	      - query the capabilities of a joystick.
       joystick_getaxis(3), joystick_getbutton(3)
	      - query the state of a joystick.
       joystick_button1|2|3|4(3),  joystick_getb1|2|3|4(3), joystick_x|y|z(3),
	      - convenience macros to query the joystick position.

   Accelerator interface (new style)
	      - calls the graphics accelerator.

   Accelerator interface (old style)
	      - copy pixmap on screen using an accelerator.
	      - fill rectangular area in video memory with a single color.
	      - draw horizontal scan lines.
	      - copy a rectangular pixmap from system memory to video memory.
	      - wait for any accelerator operation to finish.

   Controlling VC switches
	      - disables virtual console switching for safety.
	      - re-enables virtual console switching.
	      - indicates whether the program has direct access to the SVGA.
	      - enable running of the program while there is no VGA access.
	      - returns the version of the current background support.

   Debugging aids
	      - dump the contents of the SVGA registers.
       vga_gettextfont(3), vga_puttextfont(3)
	      - get/set the font used in text mode.
       vga_gettextmoderegs(3), vga_settextmoderegs(3)
	      - get/set the vga state used in text mode.
	      - toggle between text and graphics mode.
	      - set the character causing a vga_flip().

   VGA and compatibles
       320x200x256, and the series of 16-color	and  non-standard  planar  256
       color modes supported by VGAlib, as well as 720x348x2.

       Supports 640x480x256, 800x600x256, 1024x768x256 SVGA modes

   AT3D (AT25)
       Also  known  as Promotion at25. Popular as the 2D part of a voodoo rush
       card. As of this writing there are  a  few  known  problems  with  this
       driver. Read below.

   ARK Logic ARK1000PV/2000PV
       Full  support,  limited RAMDAC support. Only ARK1000PV tested. Supports
       Clocks and Ramdac lines in config file.

   ATI SVGA (VGA Wonder and friends)
       This is no real driver. I do not support any  new  modes.   However  it
       saves  additional card setup and thus allows use of the plain VGA modes
       even when you are using non standard text  modes.  It  is  possible  to
       enforce use of this driver even on ATI Mach32 but not very useful.

   ATI Mach32
       The  driver  by	Michael Weller supports all ATI BIOS-defined modes and
       more... It hits the best out of your card.  Some	 modes	may  not  have
       nice  default timings but it uses the ATI's EEPROM for custom config or
       allows to specify modes in libvga.config(5).  Some problems  may	 occur
       with  quite some third party cards (usually on board) Mach32 based con‐
       trollers as they do not completely conform to the Mach32	 data  sheets.
       Check out svgalib.mach32(7) (and libvga.config(5)).

   ATI Mach64 (rage)
       A driver for ATi Mach64 based cards with internal DAC.

   Chips  and  Technologies  chipsets  65525,  65535, 65546, 65548, 65550, and
       65554 (usually in laptops).
       This server was written using the SVGALIB patch from Sergio and	Angelo
       Masci as a starting point. This version of the code resembled the XFree
       server code that was used up to XFree 3.1.2. As such it	was  incapable
       of  programming	the  clocks,  using linear addressing, Hi-Color, True-
       Color modes or the hardware acceleration. All of	 these	features  have
       since  been  added  to  the code.  The 64200 and 64300 chips are unsup‐
       ported, however these chips are very similar to the 6554x  chips	 which
       are supported.

   Cirrus Logic GD542x/3x
       All  the	 modes, including 256 color, 32K/64K color, 16M color (3 bytes
       per pixel) and 32-bit pixel 16M color modes (5434). Some	 bitblt	 func‐
       tions are supported.  The driver doesn't work with mode dumps, but uses
       a SVGA abstraction with mode timings like the X drivers.

   Genoa(?) GVGA6400 cards.

   Hercules Stingray 64/Video
       Is supported as an ARK2000PV

   NV3 driver for the Riva128.
       This driver was written by Matan Ziv-Av and is derived from the XFree86
       driver by David J. Mckay. It lacks 24bit modes (can the card do them at
       all?), acceleration support and pageflipping in threeDKit is broken.

   Oak Technologies OTI-037/67/77/87
       Driver by Christopher Wiles; includes 32K color modes for OTI-087.

       The driver is not complete, but should work on a number	of  cards/RAM‐
       DACs, and 640x480x256 should work on most card. The best support is for
       a 801/805 with AT&T20C490-compatible RAMDAC, and S3-864	+  SDAC.   All
       256/32K/64K/16M	works  for  them  (within the bounds of video memory &
       ramdac restrictions).

       The supported cards include S3 Virge and S3 Trio64 cards.

       None of the acceleration function is supported yet.

       The chip level code should work with the 964/868/968, but  most	likely
       the card they come on would use an unsupported ramdac/clock chip.  Sup‐
       port for these chips is slowly being added.

       Clocks and Ramdac lines in libvga.config(5) supported.

       The maximum pixel clock (in MHz) of the ramdac can be set using a  Dac‐
       speed  line  in the config file. A reasonable default is assumed if the
       Dacspeed line is omitted.  Clocks should be the	same  as  in  XFree86.
       Supported  ramdac  IDs:	Sierra32K,  SC15025,  SDAC, GenDAC, ATT20C490,
       ATT20C498, IBMRGB52x.

       Clocks 25.175 28.3 40 70 50 75 36 44.9 0 118 77 31.5 110 65 72 93.5
       Ramdac att20c490
       DacSpeed 85

       Also supported, at least in combination with the SC15025/26A ramdac, is
       the  ICD 2061A clock chip.  Since it cannot be autodetected you need to
       define it in the config file using a Clockchip line. As there is no way
       to  read	 the  current settings out of the 2061, you have the option to
       specify the frequency used when switching back to text mode  as	second
       argument in the Clockchip line.

       This  is	 especially  required if your text mode is an 132 column mode,
       since these modes use a clock from the  clock  chip,  while  80	column
       modes use a fixed clock of 25 MHz.  The text mode frequency defaults to
       40 MHz, if omitted.

       ClockChip icd2061a 40.0

   Trident TVGA 8900C/9000 (and possibly also 8800CS/8900A/B)  and  also  TVGA
       Derived	from  tvgalib  by  Toomas  Losin.  TVGA	 9440  support	by ARK

       Supports 640x480x256, 800x600x256, 1024x768x256	(interlaced  and  non-
       interlaced)  Might  be useful to add 16-color modes (for those equipped
       with a 512K TVGA9000) for the 8900 and 9000 cards.

       320x200x{32K, 64K, 16M}, 640x480x{256, 32K,  64K,  16M},	 800x600x{256,
       32K,  64K,  16M}, 1024x768x{16, 256}, 800x600x{16, 256, 32K, 64K} modes
       are supported for the TVGA 9440.

       Autodetection can be forced with a:

	      chipset TVGA memory flags

       line in the config file.

       memory is the amount of VGA memory in KB, flags is  composed  of	 three

	      bit2 = false, bit1 = false
		     force 8900.

	      bit2 = false, bit1 = true
		     force 9440.

	      bit2 = true, bit1 = false
		     force 9680.

	      bit0 = true
		     force noninterlaced.

	      bit0 = false
		     force  interlaced	which  only  matters on 8900's with at
		     least 1M since there is no 512K interlaced	 mode  on  the
		     8900 or any of the other cards.

   Tseng ET4000/ET4000W32(i/p)
       Derived	from  VGAlib;  not  the same register values.  ET4000 register
       values are not compatible; see svgalib.et4000(7).

       Make sure the colors are right in hicolor  mode;	 the  vgatest  program
       should draw the same color bars for 256 and hicolor modes (the DAC type
       is defined at compilation  in  et4000.regs  or  the  dynamic  registers
       file).	ET4000/W32  based cards usually have an AT&T or Sierra 15025/6
       DAC. With recent W32p based cards, you might have some  luck  with  the
       AT&T  DAC  type.	  If the high resolution modes don't work, you can try
       dumping the registers in DOS using the program in the et4000/ directory
       and putting them in a file (/etc/vga/libvga.et4000 is parsed at runtime
       if  DYNAMIC  is	defined	 in  Makefile.cfg  at  compilation  (this   is

       Supported    modes    are   640x480x256,	  800x600x256,	 1024x768x256,
       640x480x32K, 800x600x32K, 640x480x16M, etc.

       Reports of ET4000/W32i/p functionality are welcome.

       There may be a problem with the way the hicolor DAC  register  is  han‐
       dled;  dumped  registers	 may  use  one of two timing methods, with the
       value written to the register for a particular DAC for a	 hicolor  mode
       (in  vgahico.c)	being  correct for just one of the these methods. As a
       consequence some dumped resolutions may work while others don't.

   Tseng ET6000
       Most modes of which the card is capable are supported.  The 8 15 16  24
       and 32 bit modes are supported.

       The  ET6000 has a built in DAC and there is no problem coming from that
       area. The ET6000 is capable  of	acceleration,  but  this  as  well  as
       sprites are not yet implemented in the driver.

       The  driver now uses modelines in libvga.config for user defined modes.
       It is sometimes useful to add a modeline for a  resolution  which  does
       not display well.  For example, the G400x600 is too far to the right of
       the screen using standard modes.	 This is  corrected  by	 including  in
       libvga.config the line

       Modeline "400x600@72"  25.000 400  440  488  520	  600  639  644	 666

       More examples are given below.

       This driver was provided by Don Secrest.

       Please  read  README.vesa  and  README.lrmi  in doc subdirectory of the
       standard distribution.

       Go figure! I turned off autodetection in the release, as a broken  bios
       will  be	 called	 too, maybe crashing the machine. Enforce VESA mode by
       putting a chipset VESA in the end of your libvga.config(5).

       Note that it will leave protected mode and call the cards bios  opening
       the door to many hazards.

       This  section  contains	detailed information by the authors on certain

   AT3D (AT25)
       Also known as Promotion at25. Popular as the 2D part of a  voodoo  rush

       I  have written a driver for this chipset, based on the XF86 driver for
       this chipset.

       The programs that work with this driver include all the programs in the
       demos directory, zgv and dvisvga (tmview).

       I believe it should be easy to make it work on AT24, AT6422.

   ATI Mach32
       Please see svgalib.mach32(7).

   ATI Mach64
       The  rage.c  driver works only on mach64 based cards with internal DAC.
       The driver might misdetect the base frequency the card uses, so if when
       setting	any svgalib modes the screen blanks, or complains about out of
       bound freqencies, or the display	 is  unsynced,	then  try  adding  the
       option RageDoubleClock to the config file.

   Chips  and  Technologies  chipsets  65525,  65535, 65546, 65548, 65550, and
       65554 (usually in laptops).
       Please see svgalib.chips(7).

   Tseng ET4000/ET4000W32(i/p)
       Please see svgalib.et4000(7).

   Tseng ET6000
       I have only 2 Mbytes of memory on my ET6000 card, so I am not  able  to
       get  all	 possible modes running. I haven't even tried to do all of the
       modes which I am capable of doing, but I am confident that I can manage
       more  modes  when  I have time. I have enough modes working to make the
       card useful, so I felt it was worth while to add the driver to  svgalib

       Linear  graphics	 is  working on this card, both with and without BACK‐
       GROUND enabled, and vga_runinbackground works.

       I decided it was best to quit working on more  modes  and  try  to  get
       acceleration and sprites working.

       My  et6000  card is on a PCI bus.  The card will run on a vesa bus, but
       since I don't have one on my machine I couldn't develop vesa  bus  han‐
       dling.  I quit if the bus is a vesa bus.

       I  check for an et6000 card, which can be unequivocally identified. The
       et4000 driver does not properly identify et4000 cards.  It  thinks  the
       et6000 card is an et4000, but can only run it in vga modes.

       I have found the following four modelines to be useful in libvga.config
       or in ~/.svgalibrc for proper display of some modes.

       Modeline "512x384@79" 25.175 512 560 592 640  384 428 436 494
       Modeline "400x300@72" 25.000 400 456 472 520  300 319 332 350  DOUBLES‐
       Modeline "512x480@71" 25.175 512 584 600 656  480 500 510 550
       Modeline "400x600@72" 25.000 400 440 488 520  600 639 644 666

       Don Secrest <> Aug 21, 1999

   Oak Technologies OTI-037/67/77/87
       First  a	 few  comments	of  me	(Michael  Weller <eowmob@exp-math.uni->):

       As of this writing (1.2.8) fixes were made to the oak driver  by	 Frodo
       Looijaard  <>  to  reenable OTI-067 support. It is unknown
       right now if they might have broken OTI-087 support. The author of  the
       '87  support  Christopher  Wiles	 <> owns no longer an
       OTI-087 card and can thus  no  longer  give  optimal  support  to  this
       driver.	Thus  you might be better off contacting me or Frodo for ques‐
       tions. If you are a knowledgable OTI-087 user and  experience  problems
       you  are	 welcome  to provide fixes.  No user of a OTI-087 is currently
       known to me, so if you are able to fix problems with the driver	please
       do so (and contact me) as noone else can.


       Now back to the original Oak information:

       The original OTI driver, which supported the OTI-067/77 at 640x480x256,
       has been augmented with the following features:

       1)     Supported resolutions/colors have been expanded to  640x480x32K,
	      800x600x256/32K, 1024x768x256, and 1280x1024x16.

       2)     The  OTI-087  (all  variants) is now supported.  Video memory is
	      correctly recognized.

       The driver as it exists now is somewhat schizoid.  As the '87  incorpo‐
       rates a completely different set of extended registers, I found it nec‐
       essary to split its routines from the others.  Further, I did not  have
       access  to  either  a '67 or a '77 for testing the new resolutions.  If
       using them causes your monitor/video card to fry, your dog to bite you,
       and so forth, I warned you.  The driver works on my '87, and that's all
       I guarantee.  Period.

       Heh.  Now, if someone wants to try them out ... let  me	know  if  they

       New from last release:

       32K  modes  now	work for 640x480 and 800x600.  I found that the Sierra
       DAC information in VGADOC3.ZIP is, well, wrong.	But, then  again,  the
       information for the '87 was wrong also.

       64K  modes  do  not  work.   I can't even get Oak's BIOS to enter those

       I have included a 1280x1024x16 mode, but I haven't tested it.  My moni‐
       tor can't handle that resolution.  According to the documentation, with
       2 megs the '87 should be able to do  an	interlaced  1280x1024x256  ...
       again,  I  couldn't get the BIOS to do the mode.	 I haven't 2 megs any‐
       way, so there it sits.

       I have included routines for entering and leaving  linear  mode.	  They
       should work, but they don't.  It looks like a pointer to the frame buf‐
       fer is not being passed to SVGALIB.  I've been fighting with  this  one
       for  a month.  If anyone wants to play with this, let me know if it can
       be make to work.	 I've got exams that I need to pass.

       Tidbit: I pulled the extended register info  out	 of  the  video	 BIOS.
       When  the  information  thus  obtained  failed  to work, I procured the
       OTI-087 data book.  It appears that Oak's video BIOS sets various modes
       incorrectly  (e.g.  setting  8-bit color as 4, wrong dot clock frequen‐
       cies, etc.).  Sort of makes me wonder ...

       Christopher M. Wiles (
       12 September 1994

       I think the ability to use a VGA/SVGA graphics resolution in  one  vir‐
       tual   console,	and  being able to switch to any other virtual console
       and back makes a fairly useful implementation of graphics modes in  the
       Linux console.

       Programs	 that use svgalib must be setuid root. I don't know how desir‐
       able it is to have this changed; direct port access can hardly be  done
       without.	 Root  privileges  can now be given up right after initializa‐
       tion. I noticed some unimplemented stuff in  the	 kernel	 header	 files
       that  may  be  useful,  although	 doing all register I/O via the kernel
       would incur a significant context-switching  overhead.  An  alternative
       might be to have a pseudo /dev/vga device that yields the required per‐
       missions when opened, the device being readable by  programs  in	 group

       It  is important that textmode is restored properly and reliably; it is
       fairly reliable at the moment, but  fast	 console  switching  back  and
       forth  between  two  consoles running graphics can give problems.  Wild
       virtual console switching also sometimes corrupts the contents  of  the
       textmode screen buffer (not the textmode registers or font).  Also if a
       program crashes it may write into the area  where  the  saved  textmode
       registers  are  stored,	causing textmode not be restored correctly. It
       would be a good idea to somehow store this information in a 'safe' area
       (say  a	kernel buffer). Note that the vga_safety_fork(3) thing has the
       same idea.

       Currently, programs that are in graphics mode are suspended  while  not
       in the current virtual console. Would it be a good idea to let them run
       in the background, virtualizing framebuffer actions (this should not be
       too  hard for linear banked SVGA modes)? It would be nice to have, say,
       a raytracer with a real-time display run in  the	 background  (although
       just using a separate real-time viewing program is much more elegant).

       Anyone wanting to rewrite it all in a cleaner way (something with load‐
       able kernel modules  shouldn't  hurt  performance  with	linear	frame‐
       buffer/vgagl type applications) is encouraged.

       Also,  if  anyone  feels really strongly about a low-resource and true‐
       color supporting graphical window  environment  with  cut-and-paste,  I
       believe	it  would be surprisingly little work to come up with a simple
       but very useful client-server system with shmem, the most useful appli‐
       cations	being  fairly  trivial	to  write (e.g. shell window,	bitmap
       viewer).	    And many X apps would port trivially.

       This is old information, please be sure to read svgalib.faq(7)  if  you
       are interested in further goals.

       The  latest  version  of	 svgalib  can  be  found on in
       /pub/Linux/libs/graphics or  in  /pub/linux/sources/libs
       as  svgalib-X.X.X.tar.gz.   As  of  this	 writing the latest version is
       svgalib-1.4.1.tar.gz.  There are countless mirrors of these ftp servers
       in the world. Certainly a server close to you will carry it.

       The	 original	VGAlib	     is	      on,
       pub/linux/sources/libs/vgalib12.tar.Z.	tvgalib-1.0.tar.Z  is  in  the
       same directory.

       SLS  has	 long  been  distributing an old version of VGAlib.  Slackware
       keeps a fairly up-to-date version of svgalib, but it may	 be  installed
       in  different directories from what svgalib likes to do by default. The
       current svgalib install tries to remove most of this. It	 also  removes
       /usr/bin/setmclk	 and  /usr/bin/convfont,  which	 is a security risk if
       setuid-root. Actually the recent makefiles try to do a really good  job
       to cleanup the mess which some distributions make.

       If  you	want  to recompile the a.out shared library, you will need the
       DLL 'tools' package (found on, GCC  dir).	  To  make  it
       work with recent ELF compiler's you actually need to hand patch it. You
       should probably not try to compile it. Compiling	 the  ELF  library  is
       deadly simple.

       And  here  is  a	 list  of other references which is horribly outdated.
       There are many more svgalib applications as  well  as  the  directories
       might  have  changed.   However,	 these will give you a start point and
       names to hunt for on CD's or in ftp archives.

   Viewers (in /pub/Linux/apps/graphics/viewers on
       spic   Picture viewer; JPG/PPM/GIF; truecolor; scrolling.
       zgv    Full-featured viewer with nice file selector.
	      Shows picture as it is being built up.
	      svgalib port of the Berkeley MPEG decoder (mpeg_play);  it  also
	      includes an X binary.
       flip   FLI/FLC player (supports SVGA-resolution).

   Games (in /pub/Linux/games on
       bdash  B*lderdash clone with sound.
	      Very smooth arcade asteroids game.
       yatzy  Neat mouse controlled dice game.
	      Collection of graphical card games.
	      Connect4, othello and mines.
       wt     Free state-of-the-art Doom-like engine.
	      A very nice asteroids style game port from Mac.
       Koules A game. (I've no idea what it looks like)

       In the vga directory of the SIMTEL MSDOS collection, there is a package
       called vgadoc3 which is a collection of VGA/SVGA register information.

       The XFree86 driver sources distributed with the link-kit may  be	 help‐

       There's	an  alternative RAW-mode keyboard library by Russell Marks for
       use with svgalib on

       LIBGRX, the extensive framebuffer library by  Csaba  Biegl  distributed
       with  DJGPP,  has  been	ported	to  Linux.  Contact  Hartmut  Schirmer
       (, subject prefix "HARTMUT:"). A  more	up-to-
       date  port  by  Daniel  Jackson	(  is on sun‐

       The vgalib ghostscript device driver  sources  can  be  found  on  sun‐,   /pub/Linux/apps/graphics.    Ghostscript	 patches  from
       Slackware:, /pub/linux/misc.  gnuplot patches are on sun‐

       Mitch  D'Souza  has  written font functions that work in 16 color modes
       and can use VGA textmode (codepage format) fonts; these can be found in
       his  g3fax  package  in	 These functions may go into a
       later version of svgalib.

       This section is most probably outdated, none of these problems  are  no
       longer reported.

       Using a 132 column textmode may cause graphics modes to fail. Try using
       something like 80x28.

       The console switching doesn't preserve some registers that may be  used
       to draw in planar VGA modes.

       Wild console switching can cause the text screen to be corrupted, espe‐
       cially when switching between two graphics consoles.

       On ET4000, having run XFree86 may cause high resolution modes  to  fail
       (this is more XFree86's fault).

       The  Trident  probing  routine in the XFree86 server may cause standard
       VGA modes to fail after exiting X on a Cirrus. Try putting a  'Chipset'
       line in your Xconfig to avoid the Trident probe, or use the link kit to
       build a server without the Trident driver.  Saving  and	restoring  the
       textmode	 registers with savetextmode/textmode (restoretextmode) should
       also work. [Note: svgalib now resets the particular extended  register,
       but  only  if the Cirrus driver is used (i.e. the chipset is not forced
       to VGA)] [This is fixed in XFree86 v2.1]

       Some Paradise VGA cards may not work even in standard  VGA  modes.  Can
       anyone confirm this?

       Piping  data into a graphics program has problems. I am not sure why. A
       pity, since zcatting a 5Mb FLC file into flip on a 4Mb machine would be

       The  tseng3.exe	DOS program include as source in the svgalib distribu‐
       tion doesn't recognize any modes on some	 ET4000	 cards.	  Also	ET4000
       cards  with  a  Acumos/Cirrus  DAC may only work correctly in 64K color


       svgalib.et4000(7), svgalib.chips(7), svgalib.mach32(7), vgagl(7),  lib‐
       vga.config(5),  3d(6), accel(6), bg_test(6), eventtest(6), forktest(6),
       fun(6), keytest(6), lineart(5), mousetest(6), joytest(6),  mjoytest(6),
       scrolltest(6), speedtest(6), spin(6), testaccel(6), testgl(6), testlin‐
       ear(6), vgatest(6),  plane(6),  wrapdemo(6),  convfont(1),  dumpreg(1),
       fix132x43(1),  restorefont(1),  restorepalette(1),  restoretextmode(1),
       runx(1), savetextmode(1), setmclk(1), textmode(1), mach32info(1).

       There are many authors of svgalib. This	page  was  edited  by  Michael
       Weller  <>.	The original documentation and
       most of svgalib was done by Harm Hanemaayer <>

Svgalib 1.4.1		       16 December 1999			    svgalib(7)

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