qdosmsq:vectors:putp
Table of Contents
BP_LET/SB_PUTP - Vector $120
This vector allows a parameter to either a machine code procedure or function to be changed.
| Call Parameters | Return Parameters | ||
|---|---|---|---|
| D0.L | Unused | D0.L | Error code. |
| D1.L | Unused | D1.L | Corrupted. |
| D2.L | Unused | D2.L | Corrupted. |
| D3.L | Unused | D3.L | Corrupted. |
| A0.L | Unused | A0.L | Corrupted. |
| A1.L | Unused | A1.L | Corrupted. |
| A2.L | Unused | A2.L | Corrupted. |
| A3.L | Pointer to parameter | A3.L | Preserved. |
| A6.L | SuperBASIC pointer | A6.L | May be changed. |
Errors
| ERR_BP | Bad Parameter. |
Notes
- All registers not shown above are not used on entry and are preserved on exit.
- (A3,A6.L) points to the parameter's entry in the Name Table.
- The updated value of the parameter must be put onto the maths stack.
Example
The example below shows an integer parameter being halved.
move.w CA_GTINT,A2 ; CA_GTINT vector address.
jsr (a2) ; Put the parameter on the maths stack.
bne.s Error_handler ; Oops!
asr (a1,a6.l) ; Halve the parameter.
movea.w BP_LET,(a2) ; BP_LET vector address.
jsr (a2) ; Put the new value from the maths stack.
bne.s Error_handler ; Oops!
qdosmsq/vectors/putp.txt · Last modified: 2009/02/11 14:54 by george.gwilt
