Roughly something like this:

	mkdir gcc-pdp10
	cd gcc-pdp10
	tar xf tarfile
	mkdir build
	cd build
	../src/configure --target=pdp10-dec-tops20 --with-as=macro --enable-languages=c
	(cd libiberty; make)
	(cd gcc; make cc1 xgcc)

cc1 is the raw compiler, and xgcc is the compiler driver which would
be installed as gcc if you were to type "make install" (but don't to
that).  To use xgcc pass it a -B option to locate cc1, like this:

	GCCDIR=/.../gcc-pdp10/build/gcc
	xgcc -B$GCCDIR/ ...

To link programs, you will probably need libgcc and at least a minimal
C library including some start-up code.  To compile these, you may use
the scripts found in the bin directory in the tar file.  Those depend
on expect to talk to a PDP-10 (emulator) running TOPS-20.  Provided
the scripts are running smoothly, building libgcc and the included
minimal libc is just a matter of:

	(cd /.../gcc-pdp10/build/gcc; make libgcc.a)
	(cd /.../gcc-pdp10/libc; make)

libc/crt0s.o is the stand-alone start-up code.

More details will appear here on demand.