Caused by specifically asking for or requiring memf_fast memory.  if you
don't need Chip RAM, ask for memory type 0L, or memf_clear, or
memf_public|memf_clear as applicable.  if there is fast memory available,
you will be given Fast memory.  If not, you will get Chip RAM.  May also
be caused by trackdisk-level loading of code or data over important system
memory or structures which might reside in low Chip memory on a
Chip-RAM-Only machine.