MSX Puzzle of the day - Solve this!

I deduce the word has 5 characters.

really professional cheating, manuel
(live on #msxdev ^_^)

This is how I did it:

- ASCII a=97, ASCII z=122. Divide 524 by 97 and 122 and you know the amount of characters is between about 4.29 and 5.4 characters, i.e. 5
- use a Perl script to generate all combinations of characters that sum up to 524:
for (my $i=0; $i<26; $i++)
{
for (my $j=0; $j<26; $j++)
{
for (my $k=0; $k<26; $k++)
{
for (my $l=0; $l<26; $l++)
{
for (my $m=0; $m<26; $m++)
{
if (($i+$j+$k+$l+$m+(5*97)) == 524 )
{
print chr($i+97).chr($j+97).chr($k+97).chr($l+97).chr($m+97)."\n";
}
}
}
}
}
}
and output the results to crack.txt:
perl crack.pl > crack.txt
- compare the 111510 candidates with a list of english words:
cat american-english crack.txt | sort | uniq -d
The list comes from a Linux dictionary program and the result is only 64 words
- Try all 64 words.

Thanks for the very nice puzzle, NYYRIKKI! Please explain us the hashing algo now

Is it... "brain"?

Yes, we have a winner That was fast, only 1.5h !

Thanks for the very nice puzzle, NYYRIKKI! Please explain us the hashing algo now

Well, I let someone else to explain, but below is the hash program, that I used. I think, that you tested the possibilitys by hand, but you could have searched the algorithm from your MSX.

Few tips to do that: Password is MSX2 feature, so look from SUB-ROM. You can see text "Password:" when you enter one. That is good string to search. When you find the code, disassemble it. If you have SUPER-X this is not hard.

Anyway... here is the ready to compile program for BASIC:

	DEFB #FE
	DEFW BEGIN
	DEFW END
	DEFW START

	ORG #C000

USR0:	EQU #F39A
USR:	EQU #F7F8
VALTYP:	EQU #F663

BEGIN:
START:
	LD HL,CODE
	LD (USR0),HL
	RET

CODE:
	LD	A,(VALTYP)
	CP	2
	LD	HL,(USR)
	LD	A,(HL)
	INC	HL
	JR	Z,XBASIC	; USR(VARPTR(X$)) in XBASIC
	LD	E,(HL)	; USR(X$) in BASIC
	INC	HL
	LD	D,(HL)
	EX	DE,HL
XBASIC:
	CALL	HASH
	LD	A,2
	LD	(VALTYP),A
	LD	(USR),DE
	RET

HASH:
	LD	DE,0000H
	LD	C,A
	OR	A
	RET	Z
	SCF
X2E08H:	PUSH	AF
X2E09H:	LD	B,08H
X2E0BH:	POP	AF
	PUSH	AF
	JR	NC,X2E11H
	RLC	(HL)
X2E11H:	RL	E
	RL	D
	JR	NC,X2E1FH
	LD	A,D
	XOR	80H
	LD	D,A
	LD	A,E
	XOR	05H
	LD	E,A
X2E1FH:	DJNZ	X2E0BH
	INC	HL
	DEC	C
	JR	NZ,X2E09H
	POP	AF
	RET	NC
	OR	A
	LD	C,02H
	JR	X2E08H

END:

There are plenty of these kind of pairs, here are few of them:

PIPE, SIZE
PUSH, SWEET
TAX, WAR
same, page
WHIP, peace
person, where

I used word list, that contains only 850 basic english words in uppercase and lowercase, but you propably can find plenty of more funny pairs.

Maybe next competition could be, who finds most fun MSX password pair.

Actually, I could have done it much faster... Writing the script took only about 5 minutes, running everything took less than 10 seconds. If you like I can send you the full list of words (64), but I haven't checked for all words if they would be accepted. I stopped when I found 'brain'. It's possible that more would 'fit', but maybe someone who understands the above ML program can check whether there's more of those 64 that would do the trick. (Or check by hand