Yeah right, I forgot, the encoding schemes are different.
and apparently the mfm emulator, while it could support RLL, is lacking the software support for it.
and you'll also need some conversion logic to hook it up to your Toshiba T1200, since some signals, in name they're all there, aren't quite electrically compatible.
and I've noticed the Head signal on the normal mfm/rll interface is one signal per head, while on your toshiba it's one signal for either head 0 or 1, dependent on state of signal, low or high.
Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port