https://i.imgur.com/JKBR4gZ.png

Another small modification that can be done as an expansion card (but still needs 2 additional wires). This adds back a Scorpion style button for switching the CPU speed and allows the Turbo to be enabled/disabled in ShadowMonitor/Software.
Sadly doesn't fix the TRDOS128 option with the 2.95 RAM, that still crashes after enabling turbo.