Puzzle challenge: An unusual idea, but not a new one

[BigEd]

I wrote a program today. It isn't quite working yet but it demonstrates an idea which I hope to make practical. In the meantime, perhaps you'll enjoy puzzling it out(*):

Code: Select all

0100 78       .init SEI
0101 A0 64    LDY #100
0103          .outerhi
0103 A2 30    LDX #48
0105 A9 2A    .innerhi LDA #42
0107 20 3B 01 JSR loop5
010A A9 0E    LDA #14
010C 20 74 01 JSR loop15
010F CA       DEX
0110 D0 F3    BNE innerhi
0112 A2 18    LDX #24
0114 A9 2A    .innerlo LDA #42
0116 20 3B 01 JSR loop5
0119 20 3B 01 JSR loop5
011C A9 0E    LDA #14
011E 20 74 01 JSR loop15
0121 20 74 01 JSR loop15
0124 CA       DEX
0125 D0 ED    BNE innerlo
0127 88       DEY
0128 D0 D9    BNE outerhi
012A 58       CLI
012B 60       RTS
012C 4C 00 00 JMP0
012F 4C 00 00 JMP0
0132 4C 00 00 JMP0
0135 4C 00 00 JMP0
0138 26 00    ROL0
013A 38       .go5 SEC
013B E9 01    .loop5 SBC #1
013D 4C 40 01 JMP skip5
0140 EA       .skip5 NOP
0141 D0 F8    BNE loop5
0143 60       RTS
0144 4C 00 00 JMP0
0147 4C 00 00 JMP0
014A 4C 00 00 JMP0
014D 4C 00 00 JMP0
0150 4C 00 00 JMP0
0153 4C 00 00 JMP0
0156 4C 00 00 JMP0
0159 4C 00 00 JMP0
015C 4C 00 00 JMP0
015F 4C 00 00 JMP0
0162 4C 00 00 JMP0
0165 4C 00 00 JMP0
0168 4C 00 00 JMP0
016B 4C 00 00 JMP0
016E 4C 00 00 JMP0
0171 4C 00 00 JMP0
0174 38       .loop15 SEC
0175 B0 00    BCS skip15a
0177 E9 01    .skip15a SBC #1
0179 4C 7C 01 JMP skip15b
017C EA       .skip15b NOP
017D 4C 80 01 JMP skip15c
0180 EA       .skip15c NOP
0181 4C 84 01 JMP skip15d
0184 EA       .skip15d NOP
0185 4C 88 01 JMP skip15e
0188 EA       .skip15e NOP
0189 D0 E9    BNE loop15
018B 60       RTS

In case you speak BBC Basic, here's the source:

Code: Select all

​NEW
AUTO
FOR pass=0 TO 3 STEP 3
P%=&0100
[OPT pass
.init SEI:LDY #100

.outerhi

LDX #48
.innerhi LDA #42:JSR loop5
LDA #14:JSR loop15
DEX:BNE innerhi

LDX #24
.innerlo LDA #42:JSR loop5:JSR loop5
LDA #14:JSR loop15:JSR loop15
DEX:BNE innerlo

DEY:BNE outerhi:CLI:RTS

JMP0:JMP0:JMP0:JMP0:ROL0

.go5 SEC
.loop5 SBC #1:JMP skip5
.skip5 NOP:BNE loop5:RTS

JMP0:JMP0:JMP0:JMP0:JMP0:JMP0:JMP0:JMP0
JMP0:JMP0:JMP0:JMP0:JMP0:JMP0:JMP0:JMP0

.loop15 SEC:BCS skip15a
.skip15a SBC #1:JMP skip15b
.skip15b NOP:JMP skip15c
.skip15c NOP:JMP skip15d
.skip15d NOP:JMP skip15e
.skip15e NOP:BNE loop15
RTS
]
NEXT pass

(It's an unusual kind of program, but it's not an April Fool - this is the whole thing.)

(*) In the interests of not spoiling anyone else's enjoyment, please use rot13.com or otherwise obfuscate your findings.

[White Flame]

Jung'f gur vavgvny inyhr bs gur fgnpx cbvagre?

[barrym95838]

Juvgr Synzr unf n inyvq dhrfgvba. Jura V frr rkrphgnoyr pbqr pbagnvavat ybbcrq WFEf erfvqvat vafvqr gur fgnpx cntr, V vzzrqvngryl fgneg gb fhfcrpg frys-zbqvslvat pbqr, ohg V arrq gb xabj zber guna V qb nobhg gur Orro'f eha-gvzr raivebazrag.

Mike B.

[Dr Jefyll]

barrym95838 wrote:

rkrphgnoyr pbqr [...] erfvqvat vafvqr gur fgnpx cntr

Somehow I failed to notice this, which is pretty embarrassing. Luckily, vg gheaf bhg abg gb or cregvarag.

I did PM Ed with a correction to his not-quite-finished code.

I wrote:

I suspect you've omitted 2 instructions, as shown:

Code: Select all

.innerlo
A9 2A    LDA #42
20 3B 01 JSR loop5
A9 2A    LDA #42 ; <----
20 3B 01 JSR loop5
A9 0E    LDA #14
20 74 01 JSR loop15
A9 2A    LDA #14 ; <----
20 74 01 JSR loop15

[BigEd]

Thanks for the fix Jeff - this is presently a half-baked program, but I can truthfully call it a proof of concept. I believe it shows I'm on the right track.

Using rot13.com:

Lrf, nf Wrss fnlf, gur fgnpx vf vagraqrq gb or jryy njnl sebz gur pbqr. V purpxrq ba gur Orro, naq gur fgnpx cbvagre ng bar gvzr jnf RQ (nccebcevngryl rabhtu)

Hint 1: V jnfa'g fher jurgure gb chg guvf va uneqjner be fbsgjner fhosbehz

Hint 2: V'z hfvat cntr bar orpnhfr V xabj gurer vf n cntr bar

Hint 3: Gur orro ehaf ng gjb zrtnuregm

Hint 4: Gur ynoryf ner anzrq gb uryc cbeg gur cebtenz gb n znpuvar ehaavat ng bar zrtnuregm

[nyef]

Bxnl, fb vg'f tvira gb or n hfrshy cebtenz, vg'f qrcraqrag ba gur
PCH fcrrq, vg ehaf jvgu vagreehcgf ybpxrq bhg (be nz V sbetrggvat
gur frafr bs gur V synt ntnva?), vg ehaf ragveryl jvguva gur
ertvfgre frg, vg qbrf ab boivbhf V/B, vg unf n fbzrjung
bqq-frrzvat fgehpgher jvgu dhvgr n ovg bs cnqqvat, naq vg pbhyq
unir orra va gur uneqjner fhosbehz. Bu, naq gurer'f na FRP
vafgehpgvba orgjrra ".tb5" naq ".ybbc5" gung qbrfa'g frrz gb trg
rkrphgrq sbe fbzr ernfba.

V'z guvaxvat gung guvf vf fbzr fbeg bs fvtany trarengbe gung hfrf
nqqerff yvarf sbe bhgchg. V guvax gung gur arkg fgrc gb svthevat
bhg jung guvf qbrf jbhyq or gb jbex bhg gur rknpg cnggreaf ba gur
nqqerff ohf sbe ".ybbc5" naq "ybbc15". Fbzrguvat qrsvavgryl
srryf bqq nobhg gur WZC / ABC / WZC / ABC frdhraprf gurer.

[BigEd]

> V'z guvaxvat gung guvf vf fbzr fbeg bs fvtany trarengbe
> gung hfrf nqqerff yvarf sbe bhgchg.

Gung'f vg!

[BigDumbDinosaur]

BigEd wrote:

(*) In the interests of not spoiling anyone else's enjoyment, please use rot13.com or otherwise obfuscate your findings.

V sbetbg nyy nobhg ebg13.pbz. Jura V svefg ernq nyy guvf tvoorevfu V gubhtu obgu rlrf unq tbar fbhgu ba zr!

[GARTHWILSON]

Any updates?

[BigEd]

> Any updates?
Sorry, I put this down and haven't yet picked it up. Give me another 10 days then nag me again!

[DavidBuchanan]

BigEd wrote:

> V'z guvaxvat gung guvf vf fbzr fbeg bs fvtany trarengbe
> gung hfrf nqqerff yvarf sbe bhgchg.

Gung'f vg!

Guvf vf n irel vagevthvat pbaprcg. V npghnyyl hfrq fbzrguvat fvzvyne jura V jnf grfgvat zl FOP, gb oyvax na YRQ sebz bar bs gur nqqerff yvarf (jvgu n ohssre, bs pbhefr).

Qb lbh unir n fcrpvsvp hfr sbe guvf va zvaq, be vf vg whfg n cebbs-bs-pbaprcg?

[BigEd]

Zl vqrn jnf gb genafzvg na nzcyvghqr zbqhyngrq enqvb fvtany - ybat jnir, nobhg gjb uhaqerq xvyburegm - juvpu jbhyq nyybj fbzrbar jvgu n fvzcyr fvatyr obneq pbzchgre naq ab crevcurenyf gb qhzc gurve ernq bayl zrzbel - qrpbqvat gur nhqvb jbhyq or na rkrepvfr sbe gur yvfgrare. Vagrerfgvat vqrn gb hfr n yvtug rzvggvat qvbqr sbe gung xvaq bs checbfr. Vg unf orra qbar orsber jvgu nhqvb - naq vaqrrq, vs lbh ubbx hc n fcrnxre gb gur nqqerff yvarf, vg jvyy tvir lbh gur nhqvb pbeerfcbaqvat gb gur nzcyvghqr zbqhyngvba orpnhfr vg npgf nf n ybj cnff svygre gb gur enqvb serdhrapl...

[BigEd]

Here's the follow-up post where I explain my thinking and describe my results:
viewtopic.php?f=1&t=4411