Shamu!

[ia...@admin.drake.edu]

(Sorry if this is a duplicate, Google seems to be having problems)

Shamu begins with a coarse scan of core, if something is found it is
assumed to be startup code. It backs up to the beginning of the code
and begins examining a-fields (A) (you could also examine b-fields).
If 100 < A < 7900 it lays down a spl-carpet wherever A is pointing. The
100-7900 bracket is used to keep Shamu from garbling the startup code
itself. After examining 100 locations, or if nothing was found in the
coarse scan, Shamu begins a Geist-style ssd clear.

Simple, but it is a big program. The redirection logic is hard to do.
There are a couple neat tricks in Shamu that I do not want to reveal
just yet, hoping they will be useful in another large warrior.

For an early reference to boot-pointer picking I refer you to:
http://groups.google.com/group/rec.games.corewar/browse_frm/thread/4d259b7fbb6c2a88/6cce5721d5affbfb?lnk=gst&q=pointers+pk6811s&rnum=1#6cce5721d5affbfb

Also:
http://groups.google.com/group/rec.games.corewar/browse_frm/thread/e11a05341691c1f2/a10aaf22de806929?lnk=st&q=eclipse+pk6811s&rnum=1#a10aaf22de806929

Boot pointer wiping was in vogue for a while but appears to have been
forgotten. Shamu looks to be on the 94nop hill for a while, most of
the older warriors seem to have left a-pointers in their startup code.
Of course the authors could update them :-)

Also, "Nitro Step, BOO!" on the 94 hill is the same program as Shamu on
94nop, the name is an anagram of "boot pointers".

Happy Halloween to you all!

P. Kline

[Roy]

Ah, very nice! Thats a cool idea, something you don't see very often.
It reminds me of the anti-qscan I tried to make some years ago (with
somebody on irc...you?)

The idea was: The biggest part of warriors now are the qscan tables, so
our anti-qscan-qscan, when it finds something scans the line it found.
If the A-field is between -100 and 0 (inside the qscan it means> the
real start of the warrior!) and starts bombing there. But it was too
complicated to work :(

You could also try to save the boot distance in P-space and use it in
the qscanner you might have for the 94draft hill.

Also a bomber with indirect bombing is also a fun thing to try, the
only problem is self-bombing...:
Something like this (very slow...0.28c):

bStep equ 12
bOffset equ -2

sPtr mov sSpl , *bOffset
mov sSpl , @-1
sAdd add.ab #bStep*2 , sPtr
mov.ab @sPtr , sCheck
add.b sPtr , sCheck
sCheck slt.ba #30 , #10 ;selfbomb check
jmp sPtr
djn.b sAdd , #10 ;10 selfbombs

jmp 0 , 0 ;endgame
dat 0 , 0
dat 0 , 0
dat 0 , 0

sSpl spl #bStep