29 Mar
2005
29 Mar
'05
2:26 p.m.
Well, since I don't see any more qualified replies:
On Tue, 2005-03-29 at 00:52, river wrote:
Hi,
I have a small issue with printing out the ASCII char set, from $20 to $7E inclusive.
(snip)
xri $7f ;gone too far?
jz ktest ;yes, start at SPACE again
jmp kt1 ;no, print it
Shouldn't this be jmp kt2? But
even so I don't think this would give
you all-spaces as output, maybe $20 $5f $1f ... or something.
Also, I have some SC/MP listings about and one of them
has "LD @0(P2)" instruction.
I am sure that @0(Px) is wrong, it should be @1(Px). Looking in my (not
very) trusty Osborne book, it has @0(Px), I wouldn't trust it. I have
some nice old EA article here, they use @1(Px). Maybe there is some
reason to use @0(Px) in place of 0(Px)?
From what I know, and this maybe totally wrong,
the "@" is an auto-increment/auto-
decrement bit and you must specify the
displacement for the inc/dec. If this is the case,
then what does the "0" that immediately follows the "@" do? I would
expect to see a
value other than "0" to ensure the P2 register is inc/dec by the appropriate
amount. Please, old SC/MP dudes, any help would be greatly
appreciated.
Not sure if this counts as help... gets walking stick and shuffles
off...
--
Lawrence Wilkinson lawrence at ljw.me.uk
The IBM 360/30 page http://www.ljw.me.uk/ibm360