The git repository contains a z80 assembly branch instead of the newer, more complete Forth codebase.

In the directory extracted from the .tar.gz...

See the current branch
$ git branch
	  MCMP
	  anonword
	  doloop
	* master
	  sdc
	  wip
	  z80asm

Checkout the 'z80asm' branch using:
$ git checkout z80asm
	Switched to branch 'z80asm'

Now, have another look at the current branch using:
$ git branch
	  MCMP
	  anonword
	  doloop
	  master
	  sdc
	  wip
	* z80asm

Now the files in your git repository are updated (in this case back-dated) to
the z80asm branch.