[RTTY] What Does MMTTY really send?

[aflowers at frontiernet.net]

I remembered the EXTFSK actually sends the bytes to the monitor window.  Thankfully, at least according to the byte stream in the EXTFSK window, the help file is misleading.  The TX-->USOS in MMTTY only sends a shift character in these cases:
1) after a space if either of the previous word ended with a number (e.g., "K0SM/2").  In this case it will send <SP><LTR> or <SP><FIG> in as appropriate for whatever starts the next word.  2) The next word starts with a figure.  (It always sends <FIGS> before the word in this case, regardless of what state ended the previous word).
It will not *send* a redundant letters shift between words if everything is in letters case.  I think this is equivalent to both Tiny FSK and 2Tone's logic.
Andy K0SM/2




 

    On Thursday, December 21, 2017 2:55 PM, "aflowers at frontiernet.net" <aflowers at frontiernet.net> wrote:
 

   I'm running some simulations with various contest exchanges against BER, along with the various USOS combinations that are possible.  I was reading the MMTTY manual and it says this about the TX tab:
"USOS-- turns on USOS on transmit. When you transmit a space, MMTTY also sends a LTR shift character." 
So, how does MMTTY encode this with the TX-USOS button clicked?
"W1ABC 599 05 05 NY NY"
I'm wondering if someone knows off hand so I don't have to instrument it.  Reading the help file literally, it would be this:
<LTR>W<FIG>1<LTR>ABC<SP><LTR><FIG>599<SP><LTR><FIG>05<SP><LTR><FIG>05<SP><LTR>NY<SP><LTR>NY
...where <SP> = space and the LTRS and FIGS are the shift characters.  The LTR/FIG sequence seems kinda crazy, but I'd like to know for sure so I can simulate what really out there in the wild. 
Thanks,
Andy K0SM/2