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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 sup-
       ported 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 graph-
       ics  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 programs. 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 pro-
       gram from one (but instead over a network or modem login, from within  screen(1)  or  an  xterm(1)).   Provided
       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.  Otherwise 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  Makefile.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 default.

       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_setpage(3) and vga_getgraphmem(3) (which points to the 64K VGA framebuffer) 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 view-
       ers. See the 7. References at the end of this document.

       I have added a simple VGA textmode font restoration utility (restorefont(1)) which may help if you suffer  from
       XFree86  textmode  font  corruption.  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) script.

       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  configure  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  initialization,  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 graphics 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_setmode(TEXT) to restore textmode before  program

       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

       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  inter-
       est:  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 debugger.

       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

       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 memory.

   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), joystick_getx|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

       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 spec-
       ify modes in libvga.config(5).  Some problems may occur with quite some third party cards  (usually  on  board)
       Mach32  based  controllers  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 pro-
       gramming 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 unsupported, 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 functions 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/RAMDACs, 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 unsup-
       ported ramdac/clock chip.  Support 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 Dacspeed line in the config file.  A  reason-
       able  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

       ClockChip icd2061a 40.0

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

       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 bits:

              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

       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 default)).

       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 handled; 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

   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 accelera-
       tion, 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  mode-
       line  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 chipsets.

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

       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

       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 fre-
       quency  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 now.

       Linear  graphics  is  working  on  this card, both with and without BACKGROUND enabled, and vga_runinbackground

       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 handling.  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 DOUBLESCAN
       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 <>):

       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  sup-
       port  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 questions. If you are a  knowl-
       edgable  OTI-087  user  and experience problems you are welcome to provide fixes.  No user of a OTI-087 is cur-
       rently 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

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

       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 incorporates a completely different set of
       extended registers, I found it necessary 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.

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

       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 modes.

       I have included a 1280x1024x16 mode, but I haven't  tested  it.   My  monitor  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 anyway, 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 buffer 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 frequencies, 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 virtual   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 desirable it is to have this changed; direct
       port access can hardly be done without. Root privileges can now be  given  up  right  after  initialization.  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 permissions when opened, the device being readable by programs in
       group vga.

       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 loadable kernel modules shouldn't  hurt  per-
       formance with linear framebuffer/vgagl type applications) is encouraged.

       Also,  if  anyone feels really strongly about a low-resource and truecolor supporting graphical window environ-
       ment with cut-and-paste, I believe it would be surprisingly little work to come up with a simple but very  use-
       ful  client-server  system  with  shmem, the most useful applications 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 helpful.

       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. Con-
       tact Hartmut Schirmer (, subject prefix "HARTMUT:"). A more up-to-date port by  Daniel
       Jackson ( is on

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

       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, especially when switching between two  graph-
       ics 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 fun.

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


       svgalib.et4000(7),   svgalib.chips(7),   svgalib.mach32(7),   vgagl(7),   libvga.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),   testlinear(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 <> though.

Svgalib 1.4.1                  16 December 1999                     svgalib(7)