February 17, 1994 Issue #2
______________________________________________________________________________
First off, I would like to thank everyone for the interest and comments I have
received so far. There was a large increase in the number of programs
submitted to both of the experimental hills on Stormking, as well as to the
ICWS hill. (If anyone wants to cover that hill, it's still available! ;-)
I also wanted to inform the masses about the program I used to create the
title for this newsletter. It's called figlet, and you can get it by
anonymous FTP to ftp.isu.edu:/pub/figlet. It is also being discussed in the
alt.ascii-art newsgroup.
If you are unfamiliar with the '94 draft standard, you can learn more about
it by reading the FAQ for this newsgroup. In addition, the program pMARS
includes a highly recommended tutorial on the new standard. Feel free
to send me e-mail if you have any difficulty finding either of them, if you
need to have a corewar item mailed to you, or if you have any other questions.
The FAQ is available through anonymous FTP to rtfm.mit.edu, as
/pub/usenet/news.answers/games/corewar-faq.Z
______________________________________________________________________________
The ICWS '94 Draft Hill:
Core size: 8000 instrucitons
Max processes: 8000 per program
Duration: After 80,000 cycles, a tie is declared.
Max entry length: 100 instructions
The current ICWS '94 Draft hill:
# %W/ %L/ %T Name Author Score Age
1 42/ 30/ 28 Killer instinct Anders Ivner 155 5
2 38/ 25/ 37 NC II Wayne Sheppard 152 60
3 37/ 25/ 38 Sphinx v5.1 W. Mintardjo 148 63
4 35/ 25/ 39 Snake Wayne Sheppard 145 15
5 43/ 43/ 14 Fire Storm v1.1 W. Mintardjo 143 66
6 32/ 21/ 48 ttti nandor sieben 143 16
7 42/ 42/ 16 Sylvester v1.0 Brant D. Thomsen 142 42
8 32/ 23/ 45 ttti94 nandor sieben 142 11
9 35/ 28/ 38 JustTakingALookSee J.Layland 141 59
10 43/ 45/ 12 Rave 3 Stefan Strack 140 32
11 41/ 42/ 17 SJ-4 J.Layland 139 9
12 39/ 39/ 22 Christopher Steven Morrell 139 4
13 42/ 46/ 11 Rave Stefan Strack 138 43
14 39/ 41/ 20 Fast Food v2.1 Brant D. Thomsen 138 18
15 40/ 43/ 17 Beholder's Eye v1.7 W. Mintardjo 138 72
16 40/ 43/ 17 Ntttgtstitd Simon Hovell 136 6
17 38/ 42/ 20 tiny J.Layland 134 40
18 39/ 47/ 14 Impurge 94 Fredrik Ohrstrom 132 2
19 40/ 49/ 10 Medusa's v6 Mintardjo & Strack 132 65
20 31/ 31/ 37 CG IV Brant D. Thomsen 131 1
New programs on the hill include two warriors from the KOTH hill:
"Killer instinct" and "Christopher"; as well as two new '94 warriors:
"Impurge 94" and "CG IV".
Despite the small number of new programs, the hill is really quite different.
Killer instict jumped right to the top of the hill ... probably due to all
the vampires it was able to prey upon. It's also interesting that the
programs at the top of the hill tend to be those written in the '88
standard. Again, this is a good reflection of the intensity of competition
on the KOTH hill.
______________________________________________________________________________
The ICWS '94 Draft Experimental Hill:
Core size: 55,440 instructions
Max processes: 10,000 per program
Duration: After 500,000 cycles, a tie is declared.
Max entry length: 200 instructions
The current ICWS '94 Experimental hill:
# %W/ %L/ %T Name Author Score Age
1 79/ 17/ 4 Rave 3 (55440) Stefan Strack 240 8
2 75/ 11/ 14 CG-X IV Brant D. Thomsen 239 7
3 74/ 23/ 3 No Ties Allowed Wayne Sheppard 226 13
4 68/ 22/ 10 BS J.Layland 213 15
5 65/ 23/ 12 testing testing Fredrik Ohrstrom 208 3
6 62/ 18/ 20 BigImps James Layland 206 16
7 57/ 19/ 24 Frantic 0.9 A Lee 195 17
8 59/ 33/ 9 bunker t3 P.Kline 184 4
9 56/ 28/ 16 Road Hammer 0.3 Simon Hovell 184 14
10 53/ 25/ 23 Iron Gate Wayne Sheppard 181 12
11 52/ 36/ 12 VJX-2 James Ojaste 169 1
12 36/ 53/ 11 Tiny Ring J.Layland 119 10
13 31/ 69/ 0 test 94X Anonymous 93 6
14-20 No entries
A big thanks to James Ojaste for his entry: "VJX-2".
Once again, this is an ideal hill for beginners -- you are _guaranteed_ to
get on it!
______________________________________________________________________________
HINTS and HELPS:
Before I begin with this week's hint, I need to thank Stefan Strack for
pointing out a mistake in the last issue of _The 94 Warrior_. A
MOV #a, B
command is converted to
MOV.AB #a, B
in the '94 draft, which will only move the "a" value of the instruction --
instead of the entire instruction. You will need to explicitly specify that
the instruction be
MOV.I #a, B
if you want an imp.
The following is an excerpt from the latest draft of the '94 redcode proposal.
I was actually planning to create a table similar to this for this issue's
hint, but since one already exists, I'll just pass it along instead.
A.2.1.2 ICWS'88 to ICWS'94 Conversion
The default modifier for ICWS'88 emulation is determined according
to the table below.
Opcode A-mode B-mode modifier
------------------------------------------------
DAT #$@<> #$@<> F
MOV,CMP # #$@<> AB
$@<> # B
$@<> $@<> I
ADD,SUB,MUL,DIV,MOD # #$@<> AB
$@<> # B
$@<> $@<> F
SLT # #$@<> AB
$@<> #$@<> B
JMP,JMZ,JMN,DJN,SPL #$@<> #$@<> B
------------------------------------------------
>From now on, I will explicitly be specifying the moderator for all the
instructions I supply in this newsletter -- which is probably a good idea when
writing '94 warriors as well. I have found that forcing yourself to
explicitly think about what modifier each instruction needs not only eases
the development of '94 warriors, but can also be useful for generating ideas
as well.
* * *
Since I'm already on the subject, this issue's hint will be on imp-rings and
spirals.
For those of you that are unfamiliar with exactly what imps, imp-rings, or
imp-spirals are, here is a copy of the explanation in the FAQ:
Imp - Program which only uses the MOV instruction.
example MOV 0, 1
or
example MOV 0, 2
MOV 0, 2
Imp-Gate - A location in core which is bombed or decremented
continuously so that an Imp can not pass. Also used to describe
the program-code which maintains the gate.
example ...
...
SPL 0, <example
DAT <example, #0
Imp-Ring - A minimal Imp-Spiral.
d EQU (coresize+1)/3
A MOV 0,d ; copy self to B
B MOV 0,d ; copy self to C
C MOV 0,d ; copy self to A+1
Imp-Spiral - An Imp-like program with two or more processes supporting
each other. A three-point spiral, with six processes running in
this sequence:
d EQU (coresize+1)/3
A MOV 0,d ; copy self to B
B MOV 0,d ; copy self to C
C MOV 0,d ; copy self to A+1
A+1 MOV 0,d ; copy self to B+1
B+1 MOV 0,d ; copy self to C+1
C+1 MOV 0,d ; copy self to A+2
As Paul Kline has pointed out several times in this newsgroup, imp-rings and
imp-spirals for a core of size M can be created by using steps the size of any
number that is a divisor of M*N+1, where N is an integer at least as great as
one.
Several people, including myself, had been under the misconception that if the
number M+1 is prime, than a core of size M will have no true imp-spirals
possible. This is, however, not case. For example, even though the number
55441 is prime, it is still possible to generate a 13 point imp-spiral in a
55440 size core because 55440*8+1 = 443521 = 13 * 34117.
For your convenience, I have listed the five smallest possible imp-spiral
sizes and steps for some different core sizes.
For a core of size 8000:
Point Step
----- ----
3 2667
7 1143
9 889
11 5091
13 3077
For a core of size 55440:
Point Step
----- -----
13 34117
17 35873
19 29179
23 38567
29 21029
For a core of size 8192:
Point Step
----- -----
3 2731
5 3277
7 3511
9 3641
11 2979
There have been some interesting recent developments in imp-spiral usage. A
"standard" imp-spiral (which is the type discussed in the FAQ) can be killed
by having your code decrement the B-field of a given location in the core
every turn. (Code specifically designed to kill imps, imp-rings, or
imp-spirals is also referred to as an imp-gate.) However, with the advent of
Cannonade (by Paul Kline), it was revealed that this decrementing is
insufficient for stopping _all_ imp-spirals.
Cannonade, for instance, has a "non-standard" 2668 imp-spiral followed closely
by a "standard" 2667 imp-spiral. When the 2668 imp-spiral dies on the
imp-gate, it leaves behind an instruction to replace the missing instruction
that occurs when the 2667 imp-spiral hits the gate. As a result, the 2667
imp-spiral is able to "pass through" the gate. There were also two 2668
imp-spirals posted by Pierre-Etienne Moreau (P.E.M. & E.C.) in early November
of 1993 that had some success over-writing gates through the use of varied
distances between processes.
It is possible to stop any of the above mentioned imp-spirals by using an
imp-gate such as the following:
start SPL.B 0, <-10
DAT.B <-11-2668, <-11
(Simply remove the ".B" modifiers if you are using the '88 standard.)
This code will kill any "2668" step imp-spiral, but could be over-run by an
imp-spiral with a different step ... such as a "1144" (7 point) imp-spiral.
In fact, to the best of my knowledge, it is _impossible_ to use the '88 (or
current '94) standard to create an imp-gate that will stop all possible
imp-spiral combinations.
However, with the current draft of the '94 standard, there are other options
available instead. The imp-gating method I have had the most success with is
by using the ">" operand to continuously increment the B-field of a given
location in the core. This causes the imp-spiral to move an instruction
past the point where it is supposed to, thus leaving a gap in the imp-spiral.
For an example of this technique, take a look at the following imp-gate:
start SPL.B 0, >-20
DAT.B <-11, >-21
The location twenty instructions before "start" is continually being
incremented, so any "standard" imp-spirals will be killed here. However, if a
gate-crashing imp-spiral gets past this location, it will also need to get
past the location ten instructions before "start", which is being decremented
every other turn. Since the gate-crashing imp-spiral will tend to be quite
fragile when it reaches the second location, the decrementing will usually be
enough to finish it off.
While this gate will stop the three special imp-spirals mentioned above, it is
still possible to create a series of imp-spirals that can (at least occasion-
ally) over-write it. However, this gate does have an advantage over the '88
method in its ability to work independently of the step-size of the imp-
spiral -- as well as forcing the opponent to use more complex and less
dependable imp-spiral combinations in order to over-write it.
On a final note: you can easily create a '94 imp-gate that will stop any imp-
spirals -- if the imp-spiral uses a "MOV.I 0, b" instruction instead of a
"MOV.I #a, b" instruction. Simply have an imp-gate that continually
increments the A-field at a given location. "Sylvester" uses this technique
quite effectively!
______________________________________________________________________________
Looking to the Future:
The lastest draft of the standard has been on soda.berkeley.edu for a couple
of weeks now (as /pub/corewar/incoming/icws94.0202.Z). Take a look at it
and let the newsgroup know what you think. There are some interesting
additions to the former '94 draft standard.
Also, please submit your programs to the '94 hills. We'd love to have your
best KOTH warrior on the standard '94 hill, and I've found that the best way
to learn the '94 standard is to take an '88 standard program and try to
improve it. Not only will you get the additional challenge and enjoyment of
learning the new standard, but you will be better able to correct and critique
the latest drafts of the new standard when they arrive.
If you have any comments or questions about the '94 hills or the '94
standard that you think might be of general interest, please let me know.
Good luck, and happy computing!
______________________________________________________________________________
Brant D. Thomsen, Editor Snail mail: 1197 E. 6290 S.
(bdthomse@peruvian.cs.utah.edu) Salt Lake City, UT 84121
University of Utah U.S.A.
--
Brant D. Thomsen The teaching of BASIC in schools
bdthomse@peruvian.cs.utah.edu should be considered a criminal act.
(University of Utah) - Dijkstra
|
