18 Oct
2011
18 Oct
'11
12:09 p.m.
From: "Chuck Guzis" <cclist at sydex.com>
The "red book"? I've still got the one
I bought in the 1960s.
I can send you the links to current doc.
I didn't say that S/360 didn't have
unnormalized FP operations; it
certainly did, at least according to my "green card" that I still have.
Oh I know you didn't. And I am sure you know a lot more about it than I do,
this is not my area.
I can't find anything about FP rounding
normalization bits. I thought
your reference might be to a bit in the PSW that I hadn't noticed before,
but a quick check shows otherwise.
AFAIK there are sets of instructions for use with normalized or unnormalized
operands, but I seem to recall there is also a control bit somewhere. I
don't remember what it is used for.
AFAIK IEEE floating point didn't enter into the
picture until S/390.
I thought it was earlier, maybe with XA, but I really don't know. I
remember they snuck it in there without telling me and when I found it in
the POPs I was shocked.