MDC decoding

[nhfdcadet]

might be a long shot, but does anybody have information on what sequence of tones correlates to each character of an MDC ID?

 

[Mr_Boh]

Its AFSK data, so it's not a matter of "this audio tone equals this character"

Good information here: MDC1200 Signalling

Here is a good quote:

The key to picking apart MDC-1200 was seeing that the modulated signal did not make sense as regular MSK encoding. There was no obvious alternating 1-0-1-0... bit synchronization pattern at the beginning of the data stream. For some reason, MDC-1200 exclusive-ors successive data bits just before they go to the modulator. The modulated tones then only carry the information of "this bit is different from the previous bit" or "this bit is the same as the previous bit". Thus the alternating bit synchronization pattern is transmitted as a constant tone. This XOR scheme seems to remove some information from the signal. For example, if there is a single bit receive error somewhere in the message, the recovered polarity of all successive bits is the opposite of what was intended. It is not obvious yet how an MDC-1200 decoder can recover from this.

 

[nhfdcadet]

Its AFSK data, so it's not a matter of "this audio tone equals this character"

Good information here: MDC1200 Signalling

Here is a good quote:

thanks for the info! guess what i am looking for does not exist then.

 

[gatekeep]

If you are looking for software there is WinMDC (ANTISTATIC) and Matthew Kaufmans stuff (nharper/mdc-encode-decode) and there is also MDCTool (gatekeep/MDCTool).