8-Bit Software

The BBC and Master Computer Public Domain Library

Back to 8BS Or Back to Disassembly


Page Last Altered:

AABC VPOS

Submitted by Steve Fewell

Description:

Call OSBYTE #&86 to obtain the Text cursor position. After this call, X contains the horizontal position of the cursor
(POS) and Y contains the vertical position of the cursor (VPOS).
Set A to Y (VPOS value) and jump to &AE18 to set the IWA to the 1-byte value in A and exit.


Disassembly for the VPOS routine

AABC   169 134 A9 86 LDA#&86
AABE   032 244 255 20 F4 FF JSR &FFF4 OSBYTE
AAC1   152 98 TYA
AAC2 L 076 024 174 4C 18 AE JMP &AE18 Set IWA to 8-bit value in A

 


 Back to 8BS
Or