Checks RAM on the Tandy CoCo 1 & 2 from $0000 thru $feff (or $7fff for 32k RAM CoCo's, and $3fff for 16k), inclusive, using a set of hard-coded bit patterns. Will also run on the CoCo 3, but only checks the bottom 65280 bytes.
Assembles with lwasm from lwtools, but should also assemble under EDTASM on a real CoCo with the addition of line numbers. The default make target also builds a disk image using imgtool from MAME.