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Dumping DECO Cassette System tapes noob style - help me, please!

Senil Data Systems said:
There's still a faint chance these three bits are different, because when I look at what the Multikit dongle does, it never uses the address lines EVER, but it uses 4 pins that aren't connected on the dongles I know and it looks like there's some bitstream serializing going on, so the one chip I completely broke might have been a '94 or a '194.
Click to expand...
Wow! Nice progress. I've read it twice but I need to read it again having MAME turned on.

As I mentioned before, the contents of the dongle are read on the go, while we read data from the TAPE in order to decrypt / decode the game. Once it's loaded in RAM, in theory we dont need the dongle anymore. In the Multikit, the data that is loaded is already decrypted, so no need for any dongle emulation or anything like that. Game is loaded ready to play. If there were any random dongles checks during the game, those should be patched out. The exception are those few games that actually have a bigger ROM or the ROM contains actual game DATA that is laoded into RAM as the game is being played, then you'd need the multi to behave like that type of dongle, and that's something that the multi doesnt currently support.
 
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I've just gotten word (and screenshots) that someone has managed to get my dump of The Tower running in MAME, or as Adrian Black would say "It's freakin' working!".
https://twitter.com/MameHaze/status/1493156425324974086

That would suggest the latest version of my decoder (which is attached to one of the posts on the previous side) is working, feel free to use it if you encounter any more undumped DECO games.
However I don't know if I mentioned that, but that decoder is kinda picky about the audio format. It must be wave format (.WAV) file, 8 bits, mono, no compression.
The program doesn't care about the sample rate, but you should at least end up with periods greater 10 (it uses long to store the period, so as long as your sampling rate is below - I have to guess here - 10 MHz (MEGA not kilo), you're good. The most important thing is that you don't have interrupt fighting. ATI video cards from around 1998 to 1999 are known to cause that, leading to tiny sections of the waveform missing, corrupting the data.
 
I think Crazy Climber (1980) looks even better than The Tower (1983)! That big gorilla on the the building was clearly and inspiration for Donkey Kong (1981).
 
I agree. It's as if the Nichibutsu version is an Amstrad CPC game and the DECO version is the ZX Spectrum port.

Btw. is anyone working on a DECO Megademo? (if I had the time... or the ambition... maybe in a decade or so... I still got some Interton VC4000 games and another demo on my list, it's kinda sad, the work I love to do doesn't get paid so I spend most of my awake life doing a job I don't love, but who of us isn't?)
 
Here's the two other games we have - as I said, we only have two copies of Lock'n'Chase and Mission-X. We also have an Astro Fantasia box, but it's empty. No dongle, no tape.

My code sucks. I couldn't get any of the dumps to read correct, so I did a majority vote thing. I'm pretty sure I got it right, as the Lock'n'Chase tapes are both completely identical (except one has the tape pretty chewed up).

The Mission-X has an illegal Block 100 that doesn't even appear to be the same bitrate as the rest, haven't looked at it in detail, my guess is it's just there to fool anyone who wants to copy the tape. Mission-X also isn't encrypted, all the strings are in plain text and readable.

There might still be errors in the dumps.

...and now for something completely different, I tried a transcript of the The Tower dip switch settings (uhh this website screws up the formatting even with a seemingly fixed space font, so you gotta copy'n'paste this into a text editor):

TOWER DIP SWITCHES: (trying to transcribe, makes little sense someplaces)
DIP SWITCH 1
Setting No
OFF ON OFF ON | Game Charge | 1
OFF OFF ON ON | TABLE |
1COIN 1 1 2 | UPRIGHT | 2
1PLAY 2 3 1 | (RH SELECTOR) |
------------------------------------------------|
OFF ON OFF ON | Game Charge | 3
OFF OFF ON ON | UPRIGHT |
1COIN 1 1 2 | (LH SELECTOR) | 4
1PLAY 2 3 1 | |
------------------------------------------------|
OFF ON OFF ON | ???? | 5 (I don't speak Japanese and there is no English description)
OFF OFF ON ON | | 6
1080 2080 2080 2080 | |
------------------------------------------------|
ON OFF | CONTROL | 7
UPRIGHT TABLE | PANEL |
------------------------------------------------|
ON OFF | SCREEN | 8
------------------------------------------------|


DIP SWITCH 2
Setting
OFF ON No
3 5 | Number of | 1
| Climbers |
------------------------------------------------|
OFF ON OFF ON | Bonus Points | 2
OFF OFF ON ON | Bonus Climber | 3
20000 30000 50000 70000 | |
------------------------------------------------|
OFF ON | Climber's | 4
Easy Difficult | sensitivity |
| to obstacles |
------------------------------------------------|
OFF ON | Climbers | 5
Easy Difficult | Climbing |
| Speed |
------------------------------------------------|
 

Attachments

  • deco_locknchase_missionx.zip
    30.1 KB · Views: 90
While troubleshooting my tape player I saw two Magtek ICs called 210-050 and 210-060.
I didn't find any informations on internet so I contacted MagTek which is still running and is based in California.
The support guy was really nice and provided me a datasheet of the ICs and told me they should be the same.

In the meantime , speaking with Chris Hardy of Sega Resurrection, he made a better research than me and found out a good website with informations about how swipe card readers work and it contains a nice document by Magtek on how to interface magnetic stripe readers which also have the same Magtek IC datasheet in SOIC package as used on the deco cassette reader.
https://stripesnoop.sourceforge.net/devel/magtek-io.pdf

Reading the documentation, it seems that the F/2F encoding extract bits without the need to control the speed of the magnetic media passing under the magnetic head.

if it's so it means you can run the cassette without a uniform speed and it shouldn't be a problem

I am no expert so maybe I am missing something.....
 
Hi.
I just got a Nebula tape including the dongle.
Dumping it got 4 slightly different results, each with errors in different areas, but errors were few and far between in total and I always got a majority vote, so I took the two best reads and patched their faulty parts with the two other reads, compared them to each other afterwards and they were identical.

The dongle however is different.
The x/y schema doesn't happen here, all three lines are Ys (meaning the input immediately goes to the output)

Data-LEDs:
87654ZYX
Addressbits:
12X4YZ78
The X data bit is equal to the X address bit as long as the dongle ROM is enabled. Same goes for Y and Z. Nothing is latched.

Here's the data I got for the data LEDs.
87654
00 00000 (Tower start address 1B)
01 00111
02 10011
03 01100
04 11010
05 00110 - identical until here. Utter chaos after that.
06 11000
07 11111
08 00101
09 01011
0A 10001
0B 00100
0C 10010
0D 11101
0E 10000
0F 10111
10 01001
11 11110
12 11100
13 01010
14 01111
15 10101
16 00011
17 11011
18 00001
19 10110
1A 01000
1B 00010
1C 01101
1D 11001
1E 01110
1F 10100

So... this ROM appears to have different data... or at least in a different order.
 

Attachments

  • Deconebula_tape.bin.zip
    12.1 KB · Views: 63
Can you post the raw dumps if you still have them? Dumps containt CRC and other header data. Would be good to have that.
 
The tower.txt contained in the tower.zip file I uploaded in this thread is generated by my conversion program and has the checksums from tape as well as one calculated by just adding the bytes.
I can put together all the checksums for all valid(ish) blocks my program has converted.
Knowing how to compute their checksum would be awesome because then my converter would have a way of telling that a converted block is valid.
 
Can we start with nebula? Share this one first please or both if you can.
 
Checksums of the blocks from NEBULA (there might be one or two that are wrong)
04eb, 0aa5, af8c, 4473, 2910, 9c38, b797, 9d86, fb4f, 161f, 6aae, 24cb, 2e17, 460d, ae26, 3662,
7ba8, 3313, 5995, 06d9, 8492, 6b3c, 4c8f, 2258, dd0c, 4cd0, d8e2, 9f1e, bf82, 807e, 4198, f321,
6de7, bd6d, 410a, a10a, fc80, 55ef, 4106, 98fd, 9fc1, f61d, 5349, c8dd, 586a, 7b20, 34ac, 9c8c,
5bf8, a079, 9ab3, 0578, c89a, 1522, 9b57, 5656, 2229, 1130, 1982, bf81, 34c6, 6c44, a975, f844,
5d70, 894c, d715, 2d6c, bb99, c754, b481, adb8, 1b38, d16b, a4f2, b676, b292, 51fb, 67e4, a566,
1927, 3d60, 88ca, 2049, 4aff, a5a1, b20c, a2a5, e0c4, 1162, 87d6, b7c5

Checksums of the blocks from The Tower (using dump 4 which is flawless IIRC):
c028, 1248, 1269, 2a81, fe63, 4627, 2fc6, b888, 32c7, 34de, 14a2, a02b, d7d6, 264a, 3d80, 9216,
a768, da0b, fa34, 9592, a28e, 1b78, 30b7, 0c0a, 879b, a638, 62c7, d17a, 85d9, b668, 776f, 3bbd,
98e1, d182, 25e1, f685, aeb6, d2ea, cacc, 98f5, 7102, 6ee4, 186e, ee78, b551, 87e3, 7fdd, a1f3,
7585, 92df, 2fe9, e6cb, 2c0d, 5e07, 975d, 9289, 40eb, c970, 9cae, 35d5, eff2, 04de, 6353, 3d17,
e823, 2e1d, e62b, c68b, 76c7, 346e, cad8, f620, a0e5, 84d4, a9da, f3a3, ef32, 4c31, b28e, dbf2,
0413, 6c38, c345, c0c5, 1456, c487, ddc6, b982, 0813, 1600, a928, 9520, 0c11, 3657, 920b, c30f,
b22f, 4081, 594d, 061c, 7325, c10e, a42e, 9ceb, abbd

Checksums of the blocks from Lock'n'Chase (there might be one or two that are wrong)
f309, b325, d026, 542b, c3bc, 9aa6, 7276, ea15, 7e8f, 180d, 8f27, ab0f, 9ebf, ded9, abe0, f38d,
c4f7, 3b31, 515f, d226, 8377, 6fb0, 4567, f79b, 55e3, 3e2a, 7e83, 929e, a171, 5833, 636d, a9a0,
95a8, 6fdf, bb95, fc98, c841, 3233, a6e1, f5d2, db38, 192b, 70c0, 7846, e125, a2f6, aad0, 6cdc,
9162, e143, aa4e, 0be6, 45c3, bac3, 1e9b, e429, cb9a, 3e9b, 74d0, 14de, 84fc, 007a, 91ff, 5f56,
aff7, c77f, 39d3, 9375, c078, 643a, 00b6, 17b5, 3f87, 8709, ffba, 0a6c, 18ff, 2f19, 933f, 157d,
168a, 0cb2, 9d61, 5b8d, b3ea, 53bc, 9532, c76d, c449, 9ab5, 663d, 381b, c208, dae7, 7df0, bffa,
1154, 1d20, 59fd

Checksums of the blocks from Mission X (note this dump wasn't encrypted)
a291, 03bb, 3e02, 0272, e5a1, 7789, afc5, e19d, 979d, 7801, 46ca, 0cf5, 5d22, 6bc8, 1f7c, 5b19,
8589, 6664, 2bf6, 111f, 7e57, 0b5e, 6e58, e59d, 980c, 6a9d, 3b94, 6edf, 6cbb, 60d4, 7cac, d8ef,
13cf, e4d7, b0f8, 15b7, 0ac2, 1c91, 235c, 60c1, 89ae, d5a1, 1cc0, e498, 150a, 76ec, 6104, e122,
bf4e, 42d2, 9b7b, feb8, 31d8, adbb, bd6d, 4a94, c9ea, bf2e, 1259, 8796, 907f, abec, 34d2, b41b,
417c, 0bd8, b0c3, 07b9, 54d9, 2545, 987c, 0116, d2ef, 915f, afbb, 6635, 1012, e9ce, d994, 8784,
6a97, 1c56, f77d, 9830, 1c11, eed6, 706f, 4326, be98, f366, 94bc, 022d, 3dab, 2aa9, b33f, 44cd,
f896, bdbf, be82, 4e58
[BOGUS BLOCK 100, I got word that the following blocks are from a different game, but still on the Mission-X tape]
6bcc, 3c78, 537f, df84, e8a8, 6c6f, 50b5, 722f, e95b, 0bd8, 4e5
 
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