<s>
Green	B-Error_Name
lightning	I-Error_Name
originally	O
referred	O
to	O
random	O
flashing	O
streaks	O
across	O
the	O
screen	O
of	O
IBM	B-Operating_System
3278-9	I-Operating_System
computer	B-General_Concept
terminals	I-General_Concept
,	O
which	O
were	O
produced	O
by	O
a	O
hardware	B-Error_Name
bug	I-Error_Name
when	O
a	O
new	O
symbol	O
set	O
was	O
being	O
downloaded	B-Application
.	O
</s>
<s>
Instead	O
of	O
fixing	O
the	O
fault	O
,	O
IBM	O
suggested	O
that	O
it	O
was	O
useful	O
because	O
it	O
let	O
the	O
user	O
know	O
during	O
the	O
download	B-Application
that	O
something	O
was	O
in	O
progress	O
.	O
</s>
<s>
Later	O
IBM	O
colour	O
graphics	O
terminals	O
were	O
microprocessor	B-Architecture
driven	O
and	O
would	O
not	O
have	O
produced	O
flashing	O
streaks	O
.	O
</s>
<s>
IBM	O
decided	O
to	O
program	O
them	O
to	O
re-create	O
the	O
"	O
green	B-Error_Name
lightning	I-Error_Name
"	O
,	O
since	O
the	O
bug	O
had	O
become	O
a	O
feature	O
-	O
a	O
phenomenon	O
known	O
as	O
a	O
misbug	O
.	O
</s>
