| 1 | Plex86/Bochs VGABios |
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| 2 | -------------------- |
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| 3 | |
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| 4 | The goal of this project is to have a LGPL'd Video Bios in plex86, |
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| 5 | Bochs and qemu. |
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| 6 | This VGA Bios is very specific to the emulated VGA card. |
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| 7 | It is NOT meant to drive a physical vga card. |
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| 8 | |
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| 9 | |
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| 10 | Cirrus SVGA extension |
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| 11 | --------------------- |
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| 12 | |
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| 13 | The Cirrus SVGA extension is designed for the Cirrus emulation in Bochs and |
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| 14 | qemu. The initial patch for the Cirrus extension has been written by Makoto |
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| 15 | Suzuki (suzu). |
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| 16 | |
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| 17 | |
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| 18 | Install |
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| 19 | ------- |
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| 20 | To compile the VGA Bios you will need : |
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| 21 | - gcc |
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| 22 | - bcc |
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| 23 | - as86 |
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| 24 | - ld86 |
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| 25 | |
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| 26 | Untar the archive, and type make. You should get a "VGABIOS-lgpl-latest.bin" |
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| 27 | file. Alternatively, you can use the binary file "VGABIOS-lgpl-latest.bin", |
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| 28 | i have compiled for you. |
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| 29 | |
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| 30 | Edit your plex86/bochs conf file, and modify the load-rom command in the |
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| 31 | VGA BIOS section, to point to the new vgabios image file. |
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| 32 | |
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| 33 | |
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| 34 | Debugging |
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| 35 | --------- |
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| 36 | You can get a very basic debugging system: messages printed by the vgabios. |
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| 37 | You have to register the "unmapped" device driver in plex86 or bochs, and make |
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| 38 | sure it grabs port 0xfff0. |
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| 39 | |
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| 40 | Comment the #undef DEBUG at the beginning of vgabios.c. |
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| 41 | You can then use the "printf" function in the bios. |
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| 42 | |
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| 43 | |
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| 44 | Testing |
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| 45 | ------- |
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| 46 | Look at the "testvga.c" file in the archive. This is a minimal Turbo C 2.0 |
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| 47 | source file that calls a few int10 functions. Feel free to modify it to suit |
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| 48 | your needs. |
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| 49 | |
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| 50 | |
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| 51 | Copyright and License |
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| 52 | --------------------- |
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| 53 | This program has been written by Christophe Bothamy |
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| 54 | It is protected by the GNU Lesser Public License, which you should |
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| 55 | have received a copy of along with this package. |
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| 56 | |
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| 57 | |
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| 58 | Reverse Engineering |
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| 59 | ------------------- |
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| 60 | The VGA Bios has been written without reverse-engineering any existing Bios. |
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| 61 | |
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| 62 | |
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| 63 | Acknowledgment |
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| 64 | -------------- |
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| 65 | The source code contains code ripped from rombios.c of plex86, written |
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| 66 | by Kevin Lawton <kevin2001@yahoo.com> |
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| 67 | |
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| 68 | The source code contains fonts from fntcol16.zip (c) by Joseph Gil avalable at : |
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| 69 | ftp://ftp.simtel.net/pub/simtelnet/msdos/screen/fntcol16.zip |
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| 70 | These fonts are public domain |
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| 71 | |
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| 72 | The source code is based on information taken from : |
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| 73 | - Kevin Lawton's vga card emulation for bochs/plex86 |
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| 74 | - Ralf Brown's interrupts list avalaible at |
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| 75 | http://www.cs.cmu.edu/afs/cs/user/ralf/pub/WWW/files.html |
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| 76 | - Finn Thogersons' VGADOC4b available at http://home.worldonline.dk/~finth/ |
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| 77 | - Michael Abrash's Graphics Programming Black Book |
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| 78 | - Francois Gervais' book "programmation des cartes graphiques cga-ega-vga" |
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| 79 | edited by sybex |
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| 80 | - DOSEMU 1.0.1 source code for several tables values and formulas |
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| 81 | |
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| 82 | |
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| 83 | Feedback |
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| 84 | -------- |
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| 85 | Please report any bugs, comments, patches for this VGA Bios to info@vruppert.de |
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| 86 | You can find the latest release at : http://www.nongnu.org/vgabios/ |
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| 87 | For any information on bochs, visit the website http://bochs.sourceforge.net/ |
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| 88 | For any information on qemu, visit the website http://fabrice.bellard.free.fr/qemu/ |
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| 89 | |
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| 90 | |
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| 91 | History |
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| 92 | ------- |
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| 93 | vgabios-0.5b : May 24 2005 |
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| 94 | - Volker |
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| 95 | . fixed return value for the default case in the VBE section (non-debug mode) |
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| 96 | . removed unused stuff |
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| 97 | |
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| 98 | vgabios-0.5a : Mar 07 2005 |
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| 99 | - Volker |
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| 100 | . Cirrus SVGA extension (initial patches from Makoto Suzuki, improvements |
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| 101 | from Fabrice Bellard) |
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| 102 | . vgabios image size is now exactly 32k with a checksum |
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| 103 | . a lot of vgabios and vbe functions rewritten in assembler |
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| 104 | . dynamicly generated VBE mode info list |
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| 105 | . write character function for CGA and LINEAR8 modes |
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| 106 | . read/write graphics pixel for some graphics modes |
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| 107 | . text scroll feature for some graphics modes |
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| 108 | . VBE 8-bit DAC support |
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| 109 | |
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| 110 | vgabios-0.4c : Nov 06 2003 |
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| 111 | - Christophe |
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| 112 | . fix font problem on initial screen of NT4 Loader |
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| 113 | |
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| 114 | vgabios-0.4b : Nov 04 2003 |
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| 115 | - Volker |
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| 116 | . fix offset of character tables |
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| 117 | . optimizations of CRT controller accesses |
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| 118 | . VBE i/o registers changed to 0x01CE/CF |
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| 119 | (suggestion from Daniel Gimpelevich) |
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| 120 | . "noclear" flag stored in BIOS area |
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| 121 | . fix character height returned by get_font_info function |
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| 122 | |
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| 123 | vgabios-0.4a : Aug 17 2003 |
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| 124 | - Volker |
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| 125 | . VBE mode search rewritten (VBE modes with LFB bit removed) |
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| 126 | . many bugfixes and optimizations |
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| 127 | . write character function implemented for graphics modes |
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| 128 | . support for 15bpp, 16bpp, 24bpp and 32bpp VBE modes added |
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| 129 | . SVGA mode 0x6A added |
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| 130 | . VBE modes 0x102, 0x117, 0x118 and 0x142 (Bochs specific) |
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| 131 | |
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| 132 | vgabios-0.3b : Nov 23 2002 |
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| 133 | - Christophe |
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| 134 | . added lfb-mode numbers (patch from mathis) |
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| 135 | . updated the Makefile |
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| 136 | . removed display of copyrights. |
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| 137 | . changed the Copyright string to "LGPL VGABios developers" |
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| 138 | - Volker |
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| 139 | . set the cursor shape depending on the current font height |
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| 140 | . clear BL before calling int 0x10 function 0x1103 in vgabios_init_func |
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| 141 | . added some text font functions |
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| 142 | - Jeroen |
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| 143 | . Forced to new DISPI (0xb0c1) interface (requires latest bochs vbe code) |
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| 144 | . Added multibuffering support |
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| 145 | . Added new DISPI interface for: virt width, height, x offset, y offset |
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| 146 | . Added LFB modes (to be used with the vbe-lfb patch in bochs) |
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| 147 | see VBE_HAVE_LFB in vbe.c (currently default enabled) |
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| 148 | . updated TODO & docs for changes after bochs 1.4 |
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| 149 | |
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| 150 | vgabios-0.3a : Mar 10 2002 |
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| 151 | - Christophe |
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| 152 | . Fixed bug in function ah=13 |
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| 153 | - Jeroen |
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| 154 | . updated vbebios implementation to new api |
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| 155 | . added vbe_display_api documentation |
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| 156 | . added 640x400x8, 640x480x8, 800x600x8, 1024x768 |
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| 157 | (>640x480 needs a special bochs patch atm) |
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| 158 | . added 320x200x8 vbe support (uses the standard 320x200x8 vga mode to |
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| 159 | display, this allows for testing & having something on screen as well, |
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| 160 | at least until bochs host side display is up & running) |
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| 161 | . adding lfbprof (vbe) testprogram (+some small fixes to it) |
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| 162 | . merging with vbebios 0.2 |
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| 163 | |
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| 164 | vgabios-0.2b : Nov 19 2001 |
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| 165 | - Christophe |
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| 166 | . Fixed bug in function ah=13 |
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| 167 | |
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| 168 | vgabios-0.2a : Nov 09 2001 |
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| 169 | - Christophe |
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| 170 | . Included bugfix from techt@pikeonline.net about grayscale summing |
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| 171 | . Added the "IBM" string at org 0x1e as Bart Oldeman suggested |
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| 172 | . Fixed DS and ES that where inverted in the int10 parameters list! |
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| 173 | . The following have been implemented : |
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| 174 | - function ax=1a00, ax=1a01, ah=1b |
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| 175 | - function ax=1130 |
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| 176 | . Added debug messages for unimplemented/unknown functions |
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| 177 | Must be compiled with DEBUG defined. The output is trapped |
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| 178 | by the unknown-ioport driver of plex/bochs (port 0xfff0 is used) |
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| 179 | |
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| 180 | vgabios-0.1a : May 8 2001 |
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| 181 | - Christophe |
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| 182 | . First release. The work has been focused only on text mode. |
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| 183 | . The following have been implemented : |
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| 184 | - inits |
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| 185 | - int 10 handler |
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| 186 | - functions ah=00, ah=01, ah=02, ah=03, ah=05, ah=06, ah=07, ah=08 |
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| 187 | ah=09, ah=0a, ah=0e, ah=0f, ax=1000, ax=1001, ax=1002, ax=1003 |
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| 188 | ax=1007, ax=1008, ax=1009, ax=1010, ax=1012, ax=1013, ax=1015 |
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| 189 | ax=1017, ax=1018, ax=1019, ax=101a, ax=101b, ah=12 bl=10, |
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| 190 | ah=12 bl=30, ah=12 bl=31, ah=12 bl=32, ah=12 bl=33, ah=12 bl=34 |
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| 191 | ah=13 |
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