29 Jul
2010
29 Jul
'10
1:42 p.m.
There was/is a definitive schema for in which order
vectors
should be assigned, but it is more or less not used since
all the OSes that atleast I have tried actually probe what
vector each card uses, and use that vector instead of having
some fixed scheme.
All that is required is that no two devices use the same
vector, because that would be bad.
This is coming from 25 year old memories, but I seem
to recall there being some that didn't. Back in college
we had an 11/34 that we ran RSTS, RT-11 and 6th edition
UNIX on. IIRC we had to follow the scheme exactly for
all three to work. For one system, I seem to remember
telling it the addresses and it found the vectors. On
another, we told it the vectors and it found the addresses.
On the third, we told it both. We found this out when
we didn't follow the scheme for a 3rd party serial card,
and any deviation would break one or the other.
BLS