The source is basically copied and renamed from maindec-08-d0aa-pa,
since the binaries are identical.

Doug Ingraham retyped the source for maindec-801-3a, and this work is
based on that.

I've disassembled the new code at 05400 and generally made tweaks to
the 801-3a source to accurately match the binary.

Three of these changes make no sense, at 00606, 01000, and 02414.
I have marked them in the source code with "/VRS".  It is unclear
how these instructions got mangled, and amazing that the test still
works.

        Vince