Atari ST series - Page 188

Setexec
Read/Change Exception Vector
Setexec() Opcode = 5
T his fu nction allo w s y o u to rea d or c h a n ge on e o f th e 6 80 00 ex ce p tio n v e c
to rs.
C macro format
in t v e cn u m ;
lo ng v e ca d d r, old ad d r;
old a d d r = S ete x e c(v e cn u m , v eca d d r);
Machine language format
m o v e.l
m o v e .w
m o v e .w
tra p
ad d q .l
Inputs
v ec ad d r
v ecn u m
Results
DO o ld ad d r
v e ca d d r, - (sp )
v e cn u m , - (sp )
# 5 , - (sp )
# 1 3
# 8 ,s p
lo n g
w o rd
T h e ad d re ss o f th e n ew e xce p tio n h an d le r
ro u tin e to u se for th is v e cto r. A va lu e o f
- 1 in dica tes th a t y ou ju st w ish to rea d
th e c u rre n t v e cto r a d d re ss.
T h e n u m b er of th e v ec to r to rea d o r
ch an g e. S ince each v e c to r is fou r b y tes
lo n g , th e ad d re ss = 4 * v ec to r n u m b er
lo n g T h e ad d re s s sto re d in th e v ec to r before th e call w a s
m a d e. T his a d d res s sh o u ld b e sa v ed , so y o u r p ro 
g ram can re sto re it b efore te rm in atin g.
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