@TeamZebra. Try MSX Cas Tools. It will decode part/most of the tape. It can add some fake header bytes here and there, and some bits are wrong.
The data chunk contains the begining of Metal Gear ROM (Japanese)
So I think this just proves what was obvious: the next operation (OPERATION INTRUDE N313) is Metal Gear MSX.
BTW, Big Boss/whoever should have some kind of extra hardware in his computer in order to load the game (MegaFlashROM, ESE-RAM, etc... ) (^_^!)
What parameters are you running MSX Cas Tools with? No matter how I fiddle with the input values, my output CAS file is always empty, only a few bytes long, or completely different from what you've gotten.
@TeamZebra: First remove the silence/noise from the begining of the audio.
Then configure the tool with these values:
Threshold = 10.00
Window = 1.25
Envelope = 2.0
Erase the injected by the tool "1F A6 DE BA CC 13 7D 74" and "00 00 00 00 00 00 00" chunks.
The "D3 D3 D3..." is the CLOAD header, followed by an empty filename.
After removing the file header you will get the begining of Metal Gear ROM.
"43 44 07 50" is the identification of RC750 (Metal Gear MSX)
I used a threshold value of 6 in my first test, but with 10 you will get better results.
@TeamZebra: First remove the silence/noise from the begining of the audio.
Then configure the tool with these values:
Threshold = 10.00
Window = 1.25
Envelope = 2.0
Erase the injected by the tool "1F A6 DE BA CC 13 7D 74" and "00 00 00 00 00 00 00" chunks.
The "D3 D3 D3..." is the CLOAD header, followed by an empty filename.
After removing the file header you will get the begining of Metal Gear ROM.
"43 44 07 50" is the identification of RC750 (Metal Gear MSX)
I used a threshold value of 6 in my first test, but with 10 you will get better results.
Thanks :) I'm starting to see results.
Did you clean up the audio or do any post-processing to get the data? I've trimmed the excess silence at the beginning of the audio clip, but the most I can manage to get is 457 bytes from wav2cas. If you could share your WAV file, that'd be fantastic if you did do some cleanup on it.
Your given parameters (threshold: 10.0, windows factor: 1.25, envelope correction: 2.0) resulted in an empty file for me. To get the above mentioned 457 bytes, I had to use these values:
Normalize amplitude level: TRUE
Threshold: 10.0
Window factor: 1.25
Envelope correction: 9.0
With the above parameters, here's my resulting 457 byte CAS file. The ASCII will be a little different from yours, I just used hexdump from the commandline as opposed to a GUI hex editor. Curiously, though, some of the data bytes in my results are different from yours. Though, since you got more than 457 bytes seemingly, I'm chalking that up to unreliably converted data right now.
00000000 1f a6 de ba cc 13 7d 74 ff 00 00 00 00 00 00 00 |......}t........| 00000010 1f a6 de ba cc 13 7d 74 d3 d3 d3 d3 d3 d3 d3 d3 |......}t........| 00000020 d3 d3 00 00 00 00 00 00 1f a6 de ba cc 13 7d 74 |..............}t| 00000030 41 42 f3 41 00 00 00 00 00 00 00 00 00 00 00 00 |AB.A............| 00000040 43 44 07 50 00 00 00 00 00 00 00 00 00 04 00 00 |CD.P............| 00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000060 f8 c0 12 c0 32 c0 52 c0 10 c0 11 c0 30 c0 31 c0 |....2.R.....0.1.| 00000070 50 c0 51 c0 92 68 f2 cc f4 c0 7a c0 f0 c0 71 c0 |P.Q..h....z...q.| 00000080 cd e0 41 18 4e cd e5 41 18 49 cd 7c 42 18 44 cd |..A.N..A.I.|B.D.| 00000090 fb 5c 18 3f cd c9 61 1c 3a cd af 61 18 35 cd 54 |.\.?..a.:..a.5.T| 000000a0 62 18 30 cd 4b 65 18 2b cd 51 65 18 26 cd 61 69 |b.0.Ke.+.Qe.&.ai| 000000b0 18 21 cd ee 69 18 1d cd 00 6c 18 17 cd 5d 50 18 |.!..i....l...]P.| 000000c0 12 cd fe 51 18 0d cd 91 4f 18 08 cd 00 00 00 00 |...Q....O.......| 000000d0 1f a6 de ba cc 13 7d 74 4d 18 03 ed 0e 4e 18 4e |......}tM....N.N| 000000e0 cd 15 50 18 49 cd 41 4f 18 44 cd 0c 51 18 3f cd |..P.I.AO.D..Q.?.| 000000f0 8a 71 18 3a cd 4d 61 18 35 cd b4 42 18 30 cd 93 |.q.:.Ma.5..B.0..| 00000100 4d 19 2b cd 59 4d 18 26 cd 66 4e 18 21 cd e1 43 |M.+.YM.&.fN.!..C| 00000110 18 1c cd 21 65 18 17 cd 10 51 18 12 cd 28 6f 18 |...!e....Q...(o.| 00000120 0d cf 35 51 18 08 cd 00 1f a6 de ba cc 13 7d 74 |..5Q..........}t| 00000130 99 1a 00 00 00 00 00 00 1f a6 de ba cc 13 7d 74 |..............}t| 00000140 03 cd a7 44 18 5e cd 1b 4e 18 49 cd 35 49 18 44 |...D.^..N.I.5I.D| 00000150 cd cb 4a 18 3f cd af 44 18 3a cd ac 44 18 35 cd |..J.?..D.:..D.5.| 00000160 0b 7d 18 30 cd 90 4e 18 2b cd c4 4e 18 26 cd 4b |.}.0..N.+..N.&.K| 00000170 4c 18 21 cd cd 4f 18 1c cd f3 5c 19 17 cd 4a 90 |L.!..O....\...J.| 00000180 18 12 cd 2f 4f 18 0d cd fc 4e 18 08 cd ca 73 18 |.../O....N....s.| 00000190 03 cd 84 42 18 4e cd 03 4b 18 49 cd 1d 5d 18 44 |...B.N..K.I..].D| 000001a0 cd 36 6a 18 3f cd 3e 6a 18 3a cd be 6f 18 35 cd |.6j.?.>j.:..o.5.| 000001b0 67 6f 18 30 cd 1d 4e 18 2b 00 00 00 00 00 00 00 |go.0..N.+.......| 000001c0 1f a6 de ba cc 13 7d 74 94 |......}t.|
Here's a GUI hex editor's view of my current CAS file, so you can more easily see the ASCII representation properly:
At the end of the audio file there are two short silences/cuts. I tried to manually restore the data, checking the start and stop bits of each byte. Here is the new wav.
I managed to decode a few extra bytes but, as expected, they are just more bytes from the Metal Gear ROM.
I removed the CLOAD header and extra chunks added by the tool, and replaced the missing bytes with #FFs (in red).
Some bits are wrong. But don't try to find any secret message on them. It is just Z80 opcodes (the game code).
I also checked the "end_tape" (adding to it the missing header) and it also contains chunks of the original Metal Gear ROM.
Why Konami changed the tape? Probably because they find out that some people decoded it and realized it has no sense to load a PC-6001 game on an MSX2 computer. Also, Portopia was not Operation Intrude N313.
So they 'fixed it' (it is weird loading Metal Gear ROM from tape but...) and now the circle is closed.
