Hidden utility program:
Read track $1A, sector $9 to $5E00 and track $1A, sector $8 to $5F00 and save it on a DOS 3.3 disk with the following BASIC command:

BSAVE EA TRACK WRITER UTILITY,A$5E00,L$200
This creates a utility that prompts for a starting address and track number. It will then write the 4K range of memory beginning at the start address that was entered to the track that was selected.