Entry | |
---|---|
R0 | Plot command code, |
R1 | X co-ordinate |
R2 | Y co-ordinate |
Exit | |
---|---|
R0 | Corrupted |
R1 | Corrupted |
R2 | Corrupted |
The purpose of this call is to perform a direct VDU call.
# | Description | Sequence of moves |
---|---|---|
0 | Solid line including both end points | To plot a line move to one endpoint, then plot line to other endpoint |
8 | Solid line excluding the final end point | To plot a line move to one endpoint, then plot line to other endpoint |
16 | Dotted line including both end points (pattern restarted) | To plot a line move to one endpoint, then plot line to other endpoint |
24 | Dotted line excluding the final end point (pattern restarted) | To plot a line move to one endpoint, then plot line to other endpoint |
32 | Solid line excluding 1^st^ point | To plot a line move to one endpoint, then plot line to other endpoint |
40 | Solid line excluding both end points | To plot a line move to one endpoint, then plot line to other endpoint |
48 | Dotted line excluding 1^st^ point (pattern continued) | To plot a line move to one endpoint, then plot line to other endpoint |
56 | Dotted line excluding both end points (pattern continued) | To plot a line move to one endpoint, then plot line to other endpoint |
The plot commands use the top 5 bits. The bottom 3 bits are used to specify the ‘modifier’. Most plot command codes use the standard modifier codes, however, a special set of modifiers are available for block copy/move commands.
# | Standard modifier type |
---|---|
0 | Move relative |
1 | Plot relative, foreground |
2 | Plot relative, inverse |
3 | Plot relative, background |
4 | Move absolute |
5 | Plot absolute, foreground |
6 | Plot absolute, inverse |
7 | Plot absolute, background |
# | Block copy/move modifier type |
---|---|
0 | Move relative |
1 | Relative rectangle move |
2 | Relative rectangle copy |
3 | Relative rectangle |
4 | Move absolute |
5 | Absolute rectangle move |
6 | Absolute rectangle copy |
7 | Absolute rectangle copy |
The action performed depends on the reason code value in R0.