h6. [[Programmer's Reference Manuals]] h6(. » VDU Variables h2. VDU Variables |_<^{width:3em}. #|_<^{width:3em}. Hex #|_<^{width:10em}. Name|_<^. Meaning|_<^{width:8em}. Co-ordinates [4]| |<^. 0-127|<^. &0-&7F|<^. |<^. See [[Mode Variable Numbers]]|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 128|<^. &80|<^. GWLCol|<^. Graphics Window - Lefthand Column|<^. (ic)| |<^. 129|<^. &81|<^. GWBRow|<^. Graphics Window - Bottom Row|<^. (ic)| |<^. 130|<^. &82|<^. GWRCol|<^. Graphics Window - Righthand Column|<^. (ic)| |<^. 131|<^. &83|<^. GWTRow|<^. Graphics Window - Top Row|<^. (ic)| |<^. |<^. |<^. |<^. |<^. | |<^. 132|<^. &84|<^. TWLCol|<^. Text Window - Lefthand Column|<^. | |<^. 133|<^. &85|<^. TWBRow|<^. Text Window - Bottom Row|<^. | |<^. 134|<^. &86|<^. TWRCol|<^. Text Window - Righthand Column|<^. | |<^. 135|<^. &87|<^. TWTRow|<^. Text Window - Top Row|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 136|<^. &88|<^. OrgX|<^. X coord of graphics Origin|<^. (ec)| |<^. 137|<^. &89|<^. OrgY|<^. Y coord of graphics Origin|<^. (ec)| |<^. |<^. |<^. |<^. |<^. | |<^. 138|<^. &8A|<^. GCsX|<^. Graphics Cursor X coord|<^. (ec)| |<^. 139|<^. &8B|<^. GCsY|<^. Graphics Cursor Y coord|<^. (ec)| |<^. 140|<^. &8C|<^. OlderCsX|<^. Oldest gr. Cursor X coord|<^. (ic)| |<^. 141|<^. &8D|<^. OlderCsY|<^. Oldest gr. Cursor Y coord|<^. (ic)| |<^. 142|<^. &8E|<^. OldCsX|<^. Previous gr. Cursor X coord|<^. (ic)| |<^. 143|<^. &8F|<^. OldCsY|<^. Previous gr. Cursor Y coord|<^. (ic)| |<^. 144|<^. &90|<^. GCsIX|<^. Graphics Cursor X coord|<^. (ic)| |<^. 145|<^. &91|<^. GCsIY|<^. Graphics Cursor Y coord|<^. (ic)| |<^. 146|<^. &92|<^. NewPtX|<^. New point X coord|<^. (ic)| |<^. 147|<^. &93|<^. NewPtY|<^. New point Y coord|<^. (ic)| |<^. |<^. |<^. |<^. |<^. | |<^. 148|<^. &94|<^. ScreenStart|<^. As used by VDU drivers|<^. | |<^. 149|<^. &95|<^. DisplayStart|<^. As used by display hardware|<^. | |<^. 150|<^. &96|<^. TotalScreenSize|<^. Memory allocated to screen|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 151|<^. &97|<^. GPLFMD|<^. GCOL action for foreground col|<^. | |<^. 152|<^. &98|<^. GPLBMD|<^. GCOL action for background col|<^. | |<^. 153|<^. &99|<^. GFCOL|<^. Graphics foreground col|<^. | |<^. 154|<^. &9A|<^. GBCOL|<^. Graphics background col|<^. | |<^. 155|<^. &9B|<^. TForeCol|<^. Text foreground col|<^. | |<^. 156|<^. &9C|<^. TBackCol|<^. Text background col|<^. | |<^. 157|<^. &9D|<^. GFTint|<^. Graphics foreground tint|<^. | |<^. 158|<^. &9E|<^. GBTint|<^. Graphics background tint|<^. | |<^. 159|<^. &9F|<^. TFTint|<^. Text foreground tint|<^. | |<^. 160|<^. &A0|<^. TBTint|<^. Text background tint|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 161|<^. &A1|<^. MaxMode|<^. Highest [[Screen Modes|built-in numbered mode known to kernel]]|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 162|<^. &A2|<^. GCharSizeX|<^. X size of VDU5 chars (pixels)|<^. | |<^. 163|<^. &A3|<^. GCharSizeY|<^. Y size of VDU5 chars (pixels)|<^. | |<^. 164|<^. &A4|<^. GCharSpaceX|<^. X spacing of VDU5 chars (pixels)|<^. | |<^. 165|<^. &A5|<^. GCharSpaceY|<^. Y spacing of VDU5 chars (pixels)|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 166|<^. &A6|<^. HLineAddr|<^. Address of [[Fast Horizontal Line Draw Routine|horizontal line-draw routine]]|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 167|<^. &A7|<^. TCharSizeX|<^. X size of VDU4 chars (pixels)|<^. | |<^. 168|<^. &A8|<^. TCharSizeY|<^. Y size of VDU4 chars (pixels)|<^. | |<^. 169|<^. &A9|<^. TCharSpaceX|<^. X spacing of VDU4 chars (pixels)|<^. | |<^. 170|<^. &AA|<^. TCharSpaceY|<^. Y spacing of VDU4 chars (pixels)|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 171|<^. &AB|<^. GcolOraEorAddr|<^. Addr of [[GCOL OR and EOR Address|colour blocks]] for current GCOLs|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 172|<^. &AC|<^. VIDCClockSpeed|<^. VIDC clock speed in kHz[3] |<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 174|<^. &AE|<^. |<^. Left border size[1]|<^. | |<^. 175|<^. &AF|<^. |<^. Bottom border size[1]|<^. | |<^. 176|<^. &B0|<^. |<^. Right border size[1]|<^. | |<^. 177|<^. &B1|<^. |<^. Top border size[1]|<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 192|<^. &C0|<^. |<^. Current [[GraphicsV]] driver number[2] |<^. | |<^. |<^. |<^. |<^. |<^. | |<^. 256|<^. &100|<^. WindowWidth|<^. Width of text window in chars|<^. | |<^. 257|<^. &101|<^. WindowHeight|<^. Height of text window in chars|<^. | h4. Notes Unlike the [[Mode Variable Numbers|Mode Variables]], many of the VDU variables represent changeable properties of the video system. fn1. Available from RISC OS 5.07 onwards fn2. Available from RISC OS 5.21 onwards. Also available in RISC OS Select, for the current VideoV driver number. fn3. Introduced in RISC OS 3, removed in RISC OS 5 fn4. _(ic)_ indicates values which are stored in _internal coordinates_: 0,0 is the top-left pixel of the screen, with positive X pointing right and positive Y pointing down. _(ec)_ indicates values which are stored in _external coordinates_, i.e. OS units. Positive X points right, and positive Y points up. Most external coordinates are relative to the graphics origin, except the graphics origin itself (variables 136 and 137), which is a coordinate relative to the bottom-left pixel of the screen. The XEig and YEig [[Mode Variable Numbers|mode variables]] can be used to apply the scale conversion between OS units and pixels. h4. See also * [[GCOL OR and EOR Address]] * [[Fast Horizontal Line Draw Routine]] * [[Mode Variable Numbers]] * [[OS_ReadVduVariables]]