This matches a TS MUD from 1977, and is the same as TS MUD54 with the
addition of SGC. It's nearly the same as the Tenex order we had already.
There are a few differences between 54 and 56:
- CONST is new in 56;
- Three source files in 54 were merged into others in 56: TENTAB into
READER, FLOATB into PRINT, and CHAN into FOPEN;
- DISPLA, which went between CREATE and SAVE in 54, is missing in 56.
These are analogous to TENEX's ASSEM ALL and MUD105 STINK.
This is version 56 for ITS, because the TENEX binary claimed to be
version 106, and the 54/104 and 55/105 manuals suggest that the ITS
version number tracked the TENEX one. Zork tests whether ,MUDDLE is less
than 100 to see if it's on ITS.
