OS_ReadPalette (changes)
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Programmer's OS Reference SWI Manuals Calls
» OS_ReadPalettePart 15 – SWI Calls
» OS
» OS_ReadPalette
OS_ReadPalette
(SWI &2F)
| Entry | |
|---|---|
| R0 | Logical colour |
| R1 | Type of colour |
| Exit | |
|---|---|
| R0 | Preserved |
| R1 | Preserved |
| R2 | Setting of colour (or first flashing colour if R2!=R3 on exit) |
| R3 | Setting of second flashing colour |
Use
The purpose of this call is to read the palette setting of a particular colour that is sent to the hardware. R1
selects whether the normal colour, border colour or pointer colour is read as follows:
| # | Type |
|---|---|
| 16 | Normal colour |
| 24 | Border colour |
| 25 | Pointer colour |
Notes
If R2=R3 on exit the colour requested is a non-flashing colour. The values are to interpret as follows:
| Bits | Meaning |
|---|---|
| 0-6 | Value showing how colour was programmed |
| 7 | Supremacy bit |
| 8-15 | Amount of red |
| 16-23 | Amount of green |
| 24-31 | Amount of blue |
The bottom byte returns the second parameter to the VDU 19 command. For example:
| Value | Meaning |
|---|---|
| 0-15 | Actual colour (BBC compatible) |
| 16 | Defined by giving amounts of R, G and B |
| 17-18 | Flashing colour defined by giving amounts of red, green and blue |
See also
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