Oppolzer - Informatik / Blog

No problem at all.

My point was, that the RC = 2 to me seems not important any more, because, as I
read it, the fact that the nonzero function byte was found when processing the
last byte can be derived from the fact that the remaining length in R1 +1 is 1 -
if I understand the PoOp correctly.

As far as I understand: the "interface" for TRT, regarding the first operand,
was the same as for MVC, that is, base and offset in the instruction, and length
in the instruction, limited to 256. While the interface to TRTE is much like
MVCL, that is, a register pair with address and length. And much like MVCL, the
processing may be interrupted, and the register pair is updated (but different
from MVCL, the interruption is signalled to the program by means of CC = 3).

So because the remaining length is easily accessible after TRTE, there is no
real need for CC = 2, and that's the reason, why it has been eliminated - at
least that's my guess.

Kind regards

Bernd



Am 21.10.2013 00:13, schrieb J.G.:
> "Bernd' somehow became "Bernhard' in my last post.  Anothert senior
> moment.  My apologies to Bernd.
>
> J.G.
>