.ZAP and .ZSM files are the original files from toebes website, some of the ZSMs are from his
windows assembler package exe, some transcribed from this website.

.ASM are ether symlinks to the .ZSM files or my corrections to them.
.KNOWN_GOOD are either symlinks to the unpacked ZAP files, or a known good
  assembly I made made.

JMM 2019.