VDU Variables (changes)
Showing changes from revision #7 to #8:
Added | Removed | Changed
Programmer's Reference Manuals
» VDU Variables
VDU Variables
| # | Hex # | Name | Meaning | Co-ordinates4 |
|---|---|---|---|---|
| 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 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 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 colour blocks for current GCOLs | |
| 172 | &AC | VIDCClockSpeed | VIDC clock speed in kHz3 | |
| 174 | &AE | Left border size1 | ||
| 175 | &AF | Bottom border size1 | ||
| 176 | &B0 | Right border size1 | ||
| 177 | &B1 | Top border size1 | ||
| 192 | &C0 | Current GraphicsV driver number2 | ||
| 256 | &100 | WindowWidth | Width of text window in chars | |
| 257 | &101 | WindowHeight | Height of text window in chars |
Notes
Unlike the Mode Variables, many of the VDU variables represent changeable properties of the video system.
1 Available from RISC OS 5.07 onwards
2 Available from RISC OS 5.21 onwards. Also available in RISC OS Select, for the current VideoV driver number.
3 Introduced in RISC OS 3, removed in RISC OS 5
4 (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 variables can be used to apply the scale conversion between OS units and pixels.
See also
Social
and
ROOL Store
Buy RISC OS Open merchandise here, including SD cards for Raspberry Pi and more.