Place This Hex (A Challenge Of A Sort)

[alexander]

I was kind of surprised when i asked some of my friends pointing them at a set of hex, that they couldn't place it, even though it really is not difficult. So continuing that experiment, can you place this hex (there really are a couple of hints there):

 

0000000 48eb 0090 8e02 bcd7 7a00 a0bb 8b07 8ece

0000010 8edb f3c3 eaa4 005d 07a0 0010 0001 7c00

0000020 0000 0000 0000 0000 0000 660c 558b b408

0000030 c642 1f06 7c00 c032 8966 2216 be00 0203

0000040 00ff 2000 0001 0000 0200 90fa f690 80c2

0000050 0275 80b2 59ea 007c 3100 8ec0 8ed8 bcd0

0000060 2000 a0fb 7c40 ff3c 0274 c288 be52 7d7f

0000070 34e8 f601 80c2 5474 41b4 aabb cd55 5a13

0000080 7252 8149 55fb 75aa a043 7c41 c084 0575

0000090 e183 7401 6637 4c8b be10 7c05 44c6 01ff

00000a0 8b66 441e c77c 1004 c700 0244 0001 8966

00000b0 085c 44c7 0006 6670 c031 4489 6604 4489

00000c0 b40c cd42 7213 bb05 7000 7deb 08b4 13cd

00000d0 0a73 c2f6 0f80 ea84 e900 008d 05be c67c

00000e0 ff44 6600 c031 f088 6640 4489 3104 88d2

00000f0 c1ca 02e2 e888 f488 8940 0844 c031 d088

0000100 e8c0 6602 0489 a166 7c44 3166 66d2 34f7

0000110 5488 660a d231 f766 0474 5488 890b 0c44

0000120 443b 7d08 8a3c 0d54 e2c0 8a06 0a4c c1fe

0000130 d108 6c8a 5a0c 748a bb0b 7000 c38e db31

0000140 01b8 cd02 7213 8c2a 8ec3 4806 607c b91e

0000150 0100 db8e f631 ff31 f3fc 1fa5 ff61 4226

0000160 be7c 7d85 40e8 eb00 be0e 7d8a 38e8 eb00

0000170 be06 7d94 30e8 be00 7d99 2ae8 eb00 47fe

0000180 5552 2042 4700 6f65 006d 6148 6472 4420

0000190 7369 006b 6552 6461 2000 7245 6f72 0072

00001a0 01bb b400 cd0e ac10 003c f475 00c3 0000

00001b0 0000 0000 0000 0000 f232 1549 0000 0180

00001c0 0001 fe83 083f 003f 0000 348a 0002 0000

00001d0 0901 fe82 fb3f 34c9 0002 9133 003b 0000

00001e0 fc01 fe83 ffff c5fc 003d 8d05 5716 0000

00001f0 0000 0000 0000 0000 0000 0000 0000 aa55

[phillip1882]

never read hex before, so, no.

looks like jsut a bunch of gibberish to me.

[alexander]

you dont have to read it to be able to place where it came from, length and last word give it away just fine :) ...

[CarlNGraham]

I've been working working with data and even entering Z80 machine code in hex since 1975, but I don't get this.

[alexander]

so wait hold on, the fact that its 512 bytes and ends with the word aa55 doesn't say anything...? maybe dumping strings will offer another clue?

 

(no address numbers or spaces for your convenience)

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

[Turtle]

is it a partition table?

[alexander]

close, well rather too precise :)

 

Its a dump of the first 512 bytes of my hard drive (partition table is 64 bytes starting at 01BE), and it ends with aa55, that, ladies and gentlemen is a master boot record (440 bytes of code with option of up to 446 bytes running into the next 2 sections, 4 bytes disk sig (optional), 2 bytes null (usually), 64 bytes partition table, 2 bytes MBR signature (0xAA55) always)

 

I dunno, i guess having written a tiny OS in school (i was bored, ok) it is kind of a no-brainer, and 0xAA55 is kind of forever imprinted in my brain, but there were so many hints, exactly 512 bytes is not an often occurring value and if you dump the strings, you will see a grub signature... hmm... peculiar...

 

Props Mr. Turtle :) ^_^

[CarlNGraham]

Eeer, if you say so :)

I but these things do very between implementation a bit.

I think Arc MQX used 0xFEAA557F (I think, not sure if that was for flash B) only)

[alexander]

You can do away with MBR all together, and plenty of systems dont use it, notably sparc, power pc machines, intel macs, ibm power systems and embedded devices just to name a few, but if you were to write an OS over a week or so, you would start with a simple, documented, exampled, limited, good ol' MBR...

[Turtle]

close, well rather too precise :)

 

...

Props Mr. Turtle :) ^_^

 

danke schön. :) afterall, you did say it was not really difficult and stuff like that is right up my alley don't ya know. :P