allimpc1.imp  early imp compiler that can produce an assembly code listing
../ibm360/ibm_rcode.txt possibly for the IBM360/370 in the early days of the ERCC - icl 4/75 is supposed to be very similar to an ibm360
intexts.txt   sints.txt is an Imp interpreter which calls a DECODE routine in intexts.txt
decode.imp    reconstituted decode procedure extracted from intexts
decode-77.imp decode.imp tweaked for current imp compiler


allimpc1 sort-of works but has some issues caused by the ICL 4/75 host being
big-endian and x86 machines where I've been developing, being little-endian.
So many constructs work but a few fail.  The code is currently riddled with
debugging statements.

We were able to rebuild the compiler from the Imp source on a Sparc4, which is
a big-endian machine.  The C conversion should be possile to build using the
GCC MIPS compiler whose binaries can be run on Linux under qemu emulation.