It's MSX related
Here is the last piece of the puzzle
https://a.pomf.cat/wzdclx.webm
Skip to 1:46-2:07 and reappears at 2:47 presumably for cinematic effect. I suppose when this game gets out, this sound file would be ripped.
Here is a background to the importance of the two tapes:
“People who own GZ will be able to play a different mission(s) at Camp Omega in TPP. That’s the current plan. There’s something of a big feature involved. It’s never been done in the games industry before. So I can’t go into detail about it, but I think when you experience it for yourselves you’ll be surprised. It’s something that’s only possible through video games.”
GZ has tape 1
TPP has tape 2
http://www.metalgearinformer.com/?p=16518
Probably Manuel wanted to mean that the IMSAI 8080 is not related to MSX, but the tape is.
In the video you can see Snake loading a tape on, a quite probably, MSX computer (perhaps a Sony HB F1)
I decoded the first tape and it contained a MSX BASIC file with some (random?) data in it. It was not a valid BASIC program.
The tape on the video has no header, so it could be raw data or part of a binary/BASIC file.
EDIT: listening it twice perhaps it has a header, without the pause.
Haaaa that’s awesome!
And the tape is also a BASIC program, named VOLx as the previous tape.
I tried to decode the audio but the quality is not good (also mixed with music), but this time it seems to store a real BASIC program. I could see some code fragments like ",&HC3", "&HFFxx" and an string "BY YUJI"
Also, the tape is labeled as OPERATION INTRUDE N313 (^_^)
And that Sony SDC-500 BitCorder rocks And the blue screen you see.... and the computer definitely looks like a MSX indeed, check these cursor keys
Very nice
So… I’d better finish Ground Zeroes before I start playing Phantom Pain?
So, have anyone decoded that?
The Computer is a MSX Sony HB-F1!
Has anyone been able to decode them now that they are out? The entire MGS community is going bananas because no one can solve this out. Surely someone here can, right?
So, this tape with "operation intrude" (which is mg1) is not a save file for the original mg1?
And this save file contains a *hidden* location in MG1 which you can ONLY access with this save file. Hideo kept this hidden MG1 stage a secret for 25 years? Wow, that would indeed be "...something of a big feature involved."