Issue 19 March 4, 1996
______________________________________________________________________________
Core Warrior is a weekly newsletter promoting the game of corewar. Emphasis
is placed on the most active hills--currently the '94 draft hill and the
beginner hill. Coverage will follow where ever the action is. If you have
no clue what I'm talking about then check out these five-star internet locals
for more information:
FAQs are available by anonymous FTP from rtfm.mit.edu as
pub/usenet/news.answers/games/corewar-faq.Z
FTP site is: ftp.csua.berkeley.edu /pub/corewar
Web pages are at:
http://www.stormking.com/~koth ;Stormking
http://www.ecst.csuchico.edu/~pizza/koth ;Pizza
http://pauillac.inria.fr/~doligez/corewar/ ;Planar
Newbies should check the stormking page for the FAQ, language specification,
guides, and tutorials. Post questions to rec.games.corewar.
Notice: ftp.csua.berkeley.edu is out of service, eveen is Michael
assured it will be soon OK You can download Pmars at Terry's web page:
http://www.infi.net/~wtnewton/corewar/
______________________________________________________________________________
Greetings.
Hi,
after two weeks I'm back again to you with a new issue of
Corewarrior. I'm a bit sorry for delay, but I don't know how, Myer
managed to transmit me its intestinal disease. I heard of computer
viruses transmitted in the net, but I were thinking that Montezuma
curse were not one of them :-)
This issue we have a lot of interesting posting: Frontwards v2 by
Steven Morrell, that's now near 1000 age in 94 hill, Wayne Sheppard's
Cleaver/75, an interesting imp scanning engine, and a p-space hint
written by David Boeren, maybe the 'secret of the Octupus' can be
found here.
Many thanks to them and to anyone wishing to send us something to
publish. As I tell every time, anyone wanting to join the staff is
welcome.
______________________________________________________________________________
Current Status of the Internet Pizza Server ICWS '94 Draft Hill:
Hill Specs:
coresize: 8000
max. processes: 8000
duration: after 80,000 cycles, a tie is declared.
max. entry length: 100
minimum distance: 100
rounds fought: 200
instruction set: ICWS '94 Draft
Last challenge: Mon, 4 Mar 1996 06:23:37 -0800
# %W/ %L/ %T Name Author Score Age
1 43/ 31/ 26 Grilled Octopus v0.3 David Boeren 155 34
2 44/ 36/ 20 Stepping Stone Kurt Franke 152 30
3 39/ 29/ 32 Tornado 3.0 Beppe 150 490
4 41/ 35/ 24 Chameleon M R Bremer 146 160
5 39/ 32/ 30 T.N.T. Maurizio Vittuari 146 414
6 39/ 34/ 27 Thermite II Robert Macrae 145 689
7 43/ 41/ 16 quiz Schitzo 145 1088
8 40/ 35/ 25 C I A Anders Ivner 145 1
9 42/ 40/ 18 Frontwards v2 Steven Morrell 144 941
10 27/ 14/ 59 Hazy Shade Of Winter John K W 141 317
11 44/ 47/ 10 Memories Beppe Bezzi 141 82
12 32/ 23/ 45 Clisson P.Kline 141 16
13 29/ 18/ 53 Impfinity v4g1 Planar 140 888
14 36/ 32/ 32 Torch t18 P.Kline 139 1467
15 32/ 26/ 42 Barrage Anton Marsden 139 162
16 41/ 48/ 11 Wild Card M R Bremer 135 242
17 24/ 13/ 63 Evol Cap 6.6 John Wilkinson 135 703
18 39/ 44/ 17 S.E.T.I. II John K W 134 90
19 39/ 45/ 16 Mirage 1.5 Anton Marsden 134 602
20 33/ 31/ 36 Jack in the box Beppe Bezzi 134 1455
21 22/ 10/ 68 Q.S.P. John K W 133 3
22 39/ 47/ 14 Hipshot J E Long 131 33
23 26/ 20/ 54 Blizzard Anton Marsden 131 408
24 31/ 34/ 35 Breeder V3.1 J E Long 129 31
25 4/ 0/ 0 test cia Anders Ivner 12 2
Weekly age: 150
New warriors 10 Turnover/age rate 7%
Average age: 414 ( 333 last week, 308 the week before )
Average score: 135 ( 139 last week, 139 the week before )
The 25 warriors on the hill are represented by 14
authors. Congratulation to J E Long making the 94 hill with a couple
of warriors.
Not many news this week, even if the number of challenges has been
very high. New version of the Octopus holds hilltop from its coming,
apart a very brief lead by Franke's new vampire, Stepping stone. No
other challenger did the hill in the top positions.
quiz joined the 'we have a four number age' restricted club and
Frontwards is near passing 1000 age. At present hill aging rate
Impfinity too is scheduled to pass this score for next week.
Apart the pspacers Grilled Octopus and Chameleon, and the vampire
Stepping Stone, bombers seem to be the winning strategy compared to
scanners and replicators. Qscanners too seem to have lost a little
All aged warriors hold their positions, worth noting are quiz and
Frontwards, still in the top ten.
______________________________________________________________________________
94 - What's New
# %W/ %L/ %T Name Author Score Age
1 41/ 31/ 28 Grilled Octopus v0.3 David Boeren 152 1
3 43/ 38/ 19 Stepping Stone Kurt Franke 149 1
7 38/ 36/ 26 C I A Anders Ivner 139 1
8 38/ 36/ 26 test cia Anders Ivner 139 1
12 43/ 48/ 10 Memories Beppe Bezzi 137 1
15 28/ 25/ 47 Clisson P.Kline 131 1
17 39/ 45/ 16 S.E.T.I. II John K W 132 1
21 18/ 10/ 71 Q.S.P. John K W 126 1
23 36/ 52/ 12 Hipshot J E Long 120 1
23 29/ 35/ 35 Breeder V3.1 J E Long 124 1
Two entries in the top five: Grilled Octopus v0.3 and Stepping Stone.
______________________________________________________________________________
94 - What's No More.
# %W/ %L/ %T Name Author Score Age
26 28/ 35/ 38 patroclus Kafka and Kurt 121 363
26 2/ 1/ 0 Wraith Kurt Franke 7 136
26 26/ 29/ 46 Link Kurt Franke 123 134
26 2/ 2/ 0 Grilled Octopus v0.2 David Boeren 5 133
26 0/ 1/ 3 Trade Wars P.Kline 4 38
26 2/ 1/ 0 test MT00 Beppe Bezzi 7 27
26 0/ 0/ 4 Clisson P.Kline 4 26
26 1/ 1/ 1 C I A Anders Ivner 5 26
26 0/ 0/ 3 Haziest Shade Of Winter John K W 4 14
26 34/ 48/ 19 test me 120 9
Patroclus is the only aged warrior to leave us.
______________________________________________________________________________
94 - What's Old
# %W/ %L/ %T Name Author Score Age
14 36/ 32/ 32 Torch t18 P.Kline 139 1467
20 33/ 31/ 36 Jack in the box Beppe Bezzi 134 1455
7 43/ 41/ 16 quiz Schitzo 145 1088
9 42/ 40/ 18 Frontwards v2 Steven Morrell 144 941
13 29/ 18/ 53 Impfinity v4g1 Planar 140 888
17 24/ 13/ 63 Evol Cap 6.6 John Wilkinson 135 703
6 39/ 34/ 27 Thermite II Robert Macrae 145 689
19 39/ 45/ 16 Mirage 1.5 Anton Marsden 134 602
3 39/ 29/ 32 Tornado 3.0 Beppe 150 490
5 39/ 32/ 30 T.N.T. Maurizio Vittuari 146 414
23 26/ 20/ 54 Blizzard Anton Marsden 131 408
10 27/ 14/ 59 Hazy Shade Of Winter John K W 141 317
16 41/ 48/ 11 Wild Card M R Bremer 135 242
quiz joined the the 1000+ exclusive club. 1500 milestone is at easy
reach for Torch and Jack.
______________________________________________________________________________
HALL OF FAME
* means the warrior is still running.
Pos Name Author Age Strategy
1 Torch t18 P.Kline 1467 * Bomber
2 Jack in the box Beppe Bezzi 1455 * P-warrior
3 quiz Schitzo 1088 * Scanner/ bomber
4 Frontwards v2 Steven Morrell 941 * One shot scanner
5 Iron Gate 1.5 Wayne Sheppard 926 CMP scanner
6 Agony II Stefan Strack 912 CMP scanner
7 Impfinity v4g1 Planar 888 * Stone/ imp
8 Blue Funk Steven Morrell 869 Stone/ imp
9 Thermite 1.0 Robert Macrae 802 Qscan -> bomber
10 Blue Funk 3 Steven Morrell 766 Stone/ imp
11 Night Train Karl Lewin 755 Replicator
12 Evol Cap 6.6 John Wilkinson 703 * Replicator
13 Thermite II Robert Macrae 689 * Bomber
14 HeremScimitar A.Ivner,P.Kline 666 Bomber
15 La Bomba Beppe Bezzi 650 Qscan -> replicator
16 myVamp v3.7 Paulsson 643 Vampire
17 Armory - A5 Wilkinson 609 P-warrior
18 juliet and paper Bremer & Bezzi 607 P-warrior
19 Mirage 1.5 Anton Marsden 602 * Scanner/ bomber
20 Phq Maurizio Vittuari 589 Qscan -> replicator
21 Hector 2 Kurt Franke 561 Qscan -> replicator
22 Boombastic Maurizio Vittuari 521 Bomber
23 B-Panama X Steven Morrell 518 Stone/ replicator
24 Tornado 3.0 Beppe Bezzi 490 * Bomber
25 T.N.T. Maurizio Vittuari 414 * Bomber
NC 94 and Cannonade leave the Hall, replaced by Tornado 3.0 and T.N.T.
The first 4 warriors in the hall are living, the 1500 milestone is now
near and 2000 too isn't that far.
______________________________________________________________________________
Current Status of the Internet Pizza Server Beginner's Hill:
Hill Specs:
coresize: 8000
max. processes: 8000
duration: after 80,000 cycles, a tie is declared.
max. entry length: 100
minimum distance: 100
maximum age: At age 100, warriors are retired.
rounds fought: 200
instruction set: ICWS '94 Draft
Last challenge: Mon Mar 4 21:42:59 PST 1996
# %W/ %L/ %T Name Author Score Age
1 56/ 33/ 11 Hipshot J E Long 179 27
2 45/ 19/ 36 Breeder V3 J E Long 171 47
3 43/ 21/ 37 Pretentious v0.2 Ian Oversby 164 2
4 49/ 36/ 15 Test Ian Oversby 163 1
5 48/ 35/ 16 Auntie v1.0 Ian Oversby 161 32
6 45/ 30/ 24 Evil Elf V.8 Andy Nevermind 161 36
7 37/ 14/ 49 silkworm v3.0 Brian Haskin 159 48
8 45/ 35/ 20 Judge Nutmeg Scott Manley 155 51
9 37/ 25/ 38 Hyakutake C/1996 B2 + Scott Manley 149 8
10 34/ 20/ 46 AB Scanner 2.9.4 Chris Hodson 148 62
11 41/ 38/ 22 Paralyze v0.1 Ian Oversby 144 31
12 40/ 37/ 23 Swan's Lament Chris Arguin 142 92
13 31/ 23/ 47 RingWorm_v2.7 Calvin Loh 140 38
14 42/ 44/ 14 Maniac v0.3 Ian Oversby 139 25
15 36/ 34/ 30 Hyakutake Rising Scott Manley 138 50
16 35/ 38/ 28 Forked Lite Ning 4.074 Ansel Greenwood Serm 132 55
17 27/ 26/ 47 XXXOOO v2.0 Joshua Houk 128 13
18 32/ 36/ 33 Pommes-Ketchup V1.32 S. Schroeder 128 3
19 32/ 37/ 31 Pommes-Ketchup V1.31 S. Schroeder 127 4
20 28/ 42/ 31 Blubbi V1i.0b bjoern guenzel 114 58
21 32/ 50/ 18 Pensive v0.1 Ian Oversby 113 12
22 25/ 42/ 33 Test-bomb V1.5 Jens Heunemann 108 15
23 33/ 59/ 8 Optma Dwarf v3.0 Phoenix 107 44
24 27/ 49/ 24 Pink Bunny V 2.1 Neil Padgett 106 52
25 4/ 0/ 0 El Cheapo Scanner David Boeren 12 64
Sorry, but I haven't checked the level of the beginners hill
submitting one of my warriors. J E Long leads it, with a couple of
warriors that are in the pro hill too.
______________________________________________________________________________
The Hint
Memories
Memories is my first cmp scanner of success, having climbed, in one of
its previous versions, up to the top position. I started it as a 94
improvement of the classic Iron gate, but, tweaking here and there,
it's now like my old knife I changed three times the blade and twice
the handle but it's always my old knife. :-)
The article is a bit long, but shows how to, or better how I, work to
make a warrior. Prepare your coffee, Italian of course, and be sure to
have cigarettes for the night.
Scanners are the kind of warriors that look at core and attack it only
when they find something. They can be divided in two big subclasses,
according to the instruction they use to scan the core: cmp scanners
and jmz (most usually jmz.b) scanners.
Scanner's code is composed by three parts: scan, attack and clear. The
clear is a must because usually scanners don't kill the enemy with
their attacks but drop bombs that make it generate many processes, the
so called stun attack; so we have to kill them filling core with dats
once finished our scan routine.
Wishing to make a cmp scanner I started with Wayne Sheppard's Iron
Gate, an 88 classic scoring more than 900 age in the 94 hill too. Here
is is code:
;redcode-94
;name Iron Gate
;author Wayne Sheppard
;strategy cmp scanner-SPL/JMP-Gate
dist equ 73
scan equ dist*2
add off, @x ;Scan block. It exits the b-field of the cmp
loc cmp dist-1, -1 ;instruction if the lines pointed by the cmp
slt #14, @x ;itself are different
djn -3, <7000
mov j, @loc ;Attack block. Drops a spl 0/ jmp -1 bomb and
x mov s, <loc ;restore value of b-field
sub new, @x
jmn loc, loc-1 ;attacking loc-1 line starts the core clear
s spl #0, <1-dist ;core clear that end in an imp gate
mov 2, <-2
j jmp -1
new dat <0-dist,<0-dist-1
off dat <scan, <scan
end
Worth noting is the use of indirect addressing @x every time we have
to refer to label 'loc' That's because doing such way, should any of
those @x be decremented, the warrior will continue working unhindered
because the line x-1 is pointing 'loc' too
Iron Gate has been very successful in 88 and early 94, before silk
paper come in use, but now it has to be enhanced some way to compete
with newer warriors. First step was changing the bomb, from spl/jmp to
spl/spl/jmp for a better stunning of enemy (see previous number hint)
another improvement was changing the clear from backward running to
continual forward running using > addressing.
Having a jmp -2 line to be used for the bomb I added a mov in the
clear, making it faster, even if more vulnerable. Here is first
Memories version:
[header omitted]
dist equ 229 ;not the real one
scan equ dist*2
safe equ (kill-first+2)
stun equ kill+30
jmp s+1 ;jmp to clear if hit by djn stream
first add off, @x ;scan part is the same as Iron Gate
loc cmp.f dist-1, -1 ;Only removed the djn stream to keep core clean
slt #safe, @x ;mostly for lazyness :-)
jmp first
mov j, @loc ;attack block drops a wider bomb
x mov stun, <loc ;notice that we are protected from increment
mov stun, <loc ;not only decrement
sub s, @x
jmn.b loc, loc-1
s spl #-dist, <-dist-2
mov kill, >first-1 ;forward running dat clear
mov kill, >first-1
j jmp -2, #0
off dat <scan, <scan
kill dat <2667, kill-first+6
for 5
dat 0,0
rof
for MAXLENGTH-CURLINE-12
spl #0,#0 ;Active decoy; gain with paper lose with qscan
rof
The use of one of the spl #0 of the decoy as stun is needed to avoid
self triggering.
Memories is bigger than Iron gate and has the same speed, this is
balanced by better bombs and clear. It made the 94 hill in the top 10
positions.
Second evolution was increasing the scan speed. Being 16 lines long
with a speed of .66 c we have a size speed ratio of 24, very bad
compared with those of bombers like Tornado. Big we are, why not being
bigger but faster? adding two lines we can scan at .8 c and reduce our
size/speed ratio to 22.5 I also added a decoymaker for Frontwards
pleasure :-) Here is the enhanced version:
org dmake
dist equ 509
scan equ dist*2
safe equ (last-first+1) ;decoy maker is protected
clzone equ (stun-first+1)
decoy equ -2000
dst equ 13*4
jmp s+1
first add off, @x ;80%c scan engine
loc sne.f dist-1, -1
add off, @x
seq.f *loc, @loc
slt #safe, @x
jmp first
mov j, @loc
x mov stun, <loc
mov stun, <loc
sub s, @x
jmn.b @x, loc-1
s spl #-dist, <-dist-2
mov kill, >first-1
mov kill, >first-1
j jmp -2, #0
off dat <scan, <scan
kill dat <2667, clzone
for 7
dat 0,0
rof
stun spl #0, 0
for MAXLENGTH-CURLINE-12
spl #0, #0
rof
dmake ;half the decoy is reflected at dist and invisible for me
a for 11
mov <decoy+a*dst, <decoy+dist+a*dst
rof
last
jmp first
end
This version scored King, but then come Clisson and Paul's 'Spirals
and Harmony' posting. While this version is very good against 3 pts
continual imps like Night Train it's powerless against Clisson that
includes a paper imp with 7+ pts So, to keep pace I had to fit a
spiral clear in it, increasing imp killing power at expense of being
even more fragile. The clear is like the one published by JKW in SETI,
slightly modified.
Other enhancement are one more spl in the bomb, to better contrast
paper, and the use of jmn at the end of the scan loop, not to jmp if
'first' is zero. All those details added 1.5 points to total
score. The jmp to clear if decremented line is pointless now, the
spiral clear is suicidal if decremented :-(
This is Memories as is now on the hill, as you can see it doesn't look
like Iron Gate, or first Memories version anymore, but it's still the
same warrior :-)
;redcode-94
;name Memories
;author Beppe Bezzi
;strategy cmp scanner like Iron Gate
;strategy with spl spl jmp bombs and 94 improvements
;strategy v06 changed to sne/seq scan engine
;strategy v a01 spiral clear; v b* c* super clear
;strategy v d08 details
;assert 1
;kill Memories
org dmake
dist equ 239 :not true
scan equ dist*2
safe equ (last-first+1)
clzone equ (stun-first+1)
decoy equ -2345 ;not true
dst equ 13*4
ISTEP equ 381
first sub off, @x
loc sne.f dist-1+scan, -1+scan
sub off, @x
seq.f *loc, @loc
slt #safe, @x
jmn.f first, first
mov j, @loc
x mov stun, <loc
mov stun, <loc
mov stun, <loc
sub s, @x
jmn.b @x, first
add.a #ISTEP+1,cpt
mov @-1, {cpt
j jmp -2, #0
off dat -scan, -scan
cpt spl #2, #3
kill
s spl #-dist, -dist-3
for 7
dat 0,0
rof
stun spl #0, 0
for MAXLENGTH-CURLINE-12
spl #0, #0
rof
dmake
a for 11
mov {decoy+a*dst, {decoy+dist+a*dst
rof
last
jmp loc
end
______________________________________________________________________________
Extra Extra
Frontwards v2 by Steven Morrell
Here is the version of Frontwards that is currently on the hill. I think
it is the same as the code from round 8.
The differences between the first version and this one are very subtle.
First, the SPL 30 at "cc" is not a SPL #, as it was in the original. This
avoids the logjam that can be caused trying to stun imp-rings. It also
kills off low-process bomber/scanners immediately, so that damage to the
core-clear bombs won't hurt. The other difference is an extra DAT round
of core-clearing. This does well against moderately heavy imp-rings.
Here is a map around: Most of this code is just decoy that Frontwards
doesn't detect until the second time through. The lines from p to cc
hold the scanning pointer and the battery of bombs used for the two-pass
core-clear. The 6 lines starting with top is the scan engine and the
core-clear engine.
An advantage of separating the data from the code is that the CMP
instruction doubles as the thing to add to p to get this to scan. It is
hard-wired to 2*step.
;redcode-94 verbose
;name Frontwards v2
;author Steven Morrell
;strategy One-shot/two-pass
;assert VERSION >= 80
step equ 12
offset equ 608 ;608
stream equ cc-1406 ;-806
first equ (cc-offset+202) ;203
gate equ -50
org boot
stp #1,{1
for 17
stp #1,}1
stp.b #1,{1
stp #1,{1
rof
stp #1,}1
p dat #first,{first+step
dat #30,{-1
dat #30,{-2
stp.b #30,{-3
cc spl 30,stream-660
; stp #1,{1
; stp #1,}1
boot mov top+5,top+offset+5
for 5
mov {boot,<boot
rof
boot2 mov cc,cc+offset
for 4
mov {boot2,<boot2
rof
jmp x+offset
stp #1,{1
mov {-1,<-1
; stp.b #1,{1
stp #1,{1
stp #1,}1
stp.b #1,{1
stp #1,{1
top sub x,@x
x sne *p,@p
djn.f top,<stream
spl #0,<p
mov @1,}p
djn -1,<cc
for 6
stp #1,}1
stp.b #1,{1
stp #1,{1
rof
end
"Steven C. Morrell" <morrell@math.utah.edu>
______________________________________________________________________________
Extra Extra
Cleaver /75
by Wayne Sheppard
Guys, here's the code for Cleaver/75. I was about to post it to r.g.c
when I thought that you might want to include it in the CoreWarrior.
So everyone doesn't think I was kidding, here is how I can
scan for imps with two lines of code. As a warning, this can't
catch 94 imps (mov #1234,2667), but it does detect 88 and diehard
imps. This code can catch 3, 7, and 9 point imps.
3, 7, and 9 point imps all have one thing in common, they are
all evenly divisable by 127. This has been used to make spiral
clears that can kill imps before. But it can also be used to
detect imps. If you MOD an instruction with DAT 127,127 the
result will be 0,0 if the instruction was a multiple of 127.
Then a simple JMZ.F to the imp routine.
I implemented this at the bottom of a bombing loop.
ADD offset,loc
loc MOV starta,startb
jmz.f -2,*loc
mod impdat,*loc
jmn.f -4,*loc
;impstomper starts here
The final version adds another indirect bomb for a total speed of
.75c. But 19 lines of code and no paper protection makes the final
version score too low.
;redcode-94
;name Cleaver/75
;author Wayne Sheppard
;strategy .75c bomber/scanner with active imp scan
;strategy
mod10 equ -70
starta equ hit-1+mod10
startb equ starta+mod10*2
irun equ loc-15
;hit here
hit mov bomb,*loc ;not in main loop, executed only when mod doesnt find imp
mov bomb,@loc
loc mov starta,@startb
sub s,loc
jmz.f -3,*loc ;check a-pointer
mod i127,*loc ;see if multiple of 127
jmn.f hit,*loc ;if not, bomb it and continue bombing
jmp scc ;jump to SpiralCC
i127 dat 127,127
dat 0 ;hit here
scc add.x {loc,*loc ;get impnumber into A
mov *loc,scc ;move increment to where I can use it
jmn.f 0,{loc ;back up to start of imp
mov s,*loc ;spiral SPL
add scc,loc
djn -2,#400
s spl #mod10*3,<mod10*3 ;Then CC and GATE
mov 1,<-2
bomb dat <mod10*3-1,mod10
wsheppar@st6000.sct.edu (Wayne Sheppard)
______________________________________________________________________________
Extra Extra
Pspace hints
by David Boeren
Hello! This is David Boeren providing you with an extra hint this week.
Some of you have been wondering how I've managed to jump out of nowhere and
become King of the Hill, so I've decided to write an article and tell you all
about some pspace techniques that I've been experimenting with. I hope you
all learn something, and feel free to write me if you have any questions
or ideas of how to use or improve these techniques. Remember, the Hill is
for competition, but Core Warrior is for cooperation and sharing of ideas!
This first trick is for those of you who don't want to write switching
programs, in fact, it's mostly a trick for bombers. Poor bombers always
get picked on for not being "smart", so perhaps these tips will help your
"dumb brute" shed that image :)
The basic idea is that you can use pspace to switch key data values in
your program to tune its performance. Mostly, we're talking about
changing the step size, but see below for more ideas.
I think this works best with a pspace algorithm that counts losses,
similar to the code posted from Clisson a while ago, since a switch-on-loss
algorithm is too volatile to truly measure the change in performance. What
you can do is run your regular bomber, and if you are losing too much, then
set a flag and permanently switch to the new step size for the rest of the
rounds. This kind of use of pspace is not really vulnerable to brainwashing,
the worst they can do is make you switch to your other step, not make you
change to a totally different program.
Everyone who has written a bomber knows all about what a big difference
the step size can make. You know about find-N scores, and bombing-mods,
and all that. Using a good step or using a bad step can make a sizable
difference in your performance. But a "good" step isn't always good against
EVERY opponent. Your step with a good find-23 value to whip on big scanners
is going to do poorly against smaller opponents. So why not make a self-
tuning bomber? A bomber that attempts to adjust itself to find a good step
vs. each opponent?
The code isn't that hard, and it depends a bit on the details of your
switching algorithm, but basically if you're using a switcher like Clisson
which tracks total performance (whether or not you use a mod-property to
detect brainwash) then you can have something like this:
step equ 95
stepz equ 184 ; "second chance" step
SLT.B *PRESULT, #thresh ; See if old step is losing...
MOV.A #stepz, loop+1 ; Try a new step
You just see if your win/loss accumulated total has slipped below a
certain threshold, and if so then you alter your bomber to a new step.
Now, this code doesn't trigger a permanent switch on its own, but it's
quite small and it WILL continue to switch the the backup step every time
the score falls below the desired performance point. Is it better to
switch permanently? I don't think I know yet, but I DO know that it's
riskier. You don't want a little bad luck early in the rounds to make you
change to a worse step if you can help it. If you want a permanent switch,
think carefully about what point to place your threshold! Depending on your
code, it will hopefully only take one or possibly two MOVs to re-code your
bomber with the new step, so this should not cost you too much in terms of
speed. I'd do it up front before you boot.
Altering boot distance with pspace seems more uncertain than altering
step sizes, but you can try it if you like. Perhaps a better idea is
altering your bomb to fit the opponent. Let's say that you have a bomber
with a 2-instruction bomb. With only one MOV instruction, you can change
that bomb from SPL/JMP -1 for papers to STP/JMP -1 for brainwashing to
DAT/JMP -1 for a DAT bomber. I'd recommend using this setup with the
mini-vamp technique used by warriors like Quiksand and Koolaid, which let
you drop the equivalent of three 2-instruction bombs in a loop at .5c, which
is fast and makes the "waste" for the DAT/JMP-1 bomb minimal. Of course
don't forget to follow your bombing run up with your usual coreclear!
Did you know that any DAT bomber with a SPL/SPL/DAT coreclear can turn
into a nice paper-muncher by altering your step so that your bombing run
terminates after only one pass through the bombing loop? Sometimes I wonder
if I ought to be telling you guys all this stuff :)
What would happen if you pswitched bombs between an anti-imp bomb and
some other bomb? What if you did this with your paper? Could your program
adapt to the imp-number of the opponent's spiral? What about if your
vampire pswitched one instruction in its pit between a SPL and an STP, would
that give you better scores vs. pspacers while still letting you hit the
papers just as hard? Try it!
The next technique is something to help protect you from brainwashers. Some
of you probably know about this already, but I'm sure not everyone does.
Basically, there are two types of brainwashes that I know about. One type
tries to pick up your pspace pointers and brainwash you through them. The
other type does essentially a coreclear of your pspace, looping to overwrite
all of it with all zeros, random junk, or whatever. I call these second types
"Brainwash Pits", even if they don't come from a Vampire.
The first type of brainwash is not dissimilar to programs that try to find
your boot pointer and attack you through it, and the defense is the same as
well. Just be sure to erase all of your pspace pointers after using them.
Let me show you how I do this in Grilled Octopus:
sflag DAT.F #pdata1, #pdata2 ; pspace pointers
pflag DAT.F #pdata3, #pdata4 ; more pspace pointers
boot_component
MOV.I 0, sflag ; Safety-net for our pspace stuff
MOV.I 0, pflag
boot MOV.I clear+1, bdist ; fast boot away tail first
for N
MOV.I {boot, <boot
rof
ADD.AB #3, boot ; adjust to split to the correct start
SPL.B @boot, #1 ; split to main program
MOV.I 0, boot ; obliterate boot pointer
DAT.F #0, #0 ; die
By using this type of boot routine and keeping all my pspace pointers
packed into a couple of DAT elements, I can erase my "dangerous" data
quickly. The SPL booting method lets me split to my main program and
leave one process behind to wipe my boot pointer to protect me from
papers that like to do A-indirect bombing. To access pspace, all I have
to do is have my LDP/STP instructions reference the sflag and pflag
instructions with the appropriate .AB type modifiers. Although most of the
pspace code I've found in the archives always uses immediate mode to
access pspace, there is no reason why this has to be so.
I think that the whole area of dynamically recoding programs based on
pspace performance data is very underexplored at the moment, and that
some of you may like to try a few experiments. Maybe you think that it's
not worthwhile, but hopefully the Hill standings will convince some of
you that I know something about pspace after all :)
Anyway, if there is interest in hearing more about pspace techniques,
then I will probably write another article soon covering inexpensive
brainwash detection, or perhaps more information on how programs which
do not use component switching can benefit from using pspace as a tuning
mechanism. I am also considering a description of how to use multiple
pspace algorithms in conjunction with each other, such as Grilled Octopus
uses. Please everyone feel free to email me and let me know what you think
of the ideas presented in this article and what you'd be interested in
learning more about in the future, ok?
David Boeren <akemi@netcom.com>
______________________________________________________________________________
Questions? Concerns? Comments? Complaints? Mail them to people who care:
Beppe Bezzi <bezzi@iol.it> or Myer R Bremer <bremermr@ecn.purdue.edu>
Joined the staff this week, in alfabetical order:
David Boeren <akemi@netcom.com>, Steven C. Morrell <morrell@math.utah.edu>, Wayne Sheppard <wsheppar@st6000.sct.edu>
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