"Decle" wrote the following interesting comment on my second Science Fair video:

@decle • 7 hours ago The virtual machine and monitor within the SFMT code is implemented in about 1K (the other 1K of memory is used for the 6 built in games). It's really very impressive when you look at the disassembly. Although the TMS1100 has 128 nibbles of RAM, only 80 are available for you program code. There rest is used for the internal state of the virtual machine. 16 nibbles are used for the data memory available to your code. 10 nibbles are reserved for the virtual machine registers and the rest is used to record state like key presses, hex output values etc.

I think he is probably referring to the ROM bits that have been read out by Sean Riddle: 

https://www.seanriddle.com/tms1100.html