The Aculab Floppy Tape has built-in firmware that can only be used in ROM BASIC.
Typically this means starting with "trs80gp -m1 -dx -aft"
It must be initialized by typing SYSTEM and /12345.  It will show a banner:

   *** ACULAB FLOPPY TAPE OPERATING SYSTEM V3.4 ***
READY
>_

Wafers can store up to 32 files and at most have 253 sectors of 256 bytes each.

Commands are similar to disk BASIC but with @ prefixed:

@NEW			initialize wafer (erasing all files)
@LIST			show directory of wafer
@SAVE"PROG/BAS"		save BASIC program
@LOAD"PROG/BAS"		load BASIC program
@RUN"PROG/BAS"		run BASIC program
@MERGE"PROG/BAS"	merge BASIC program with the one in memory
@KILL"PROG/BAS"		delete file

@RUN"PROG/CIM"			run a machine language program
@SAVE"PROG/CIM",5,32000		save 5*256 bytes starting at 32000
@SAVE"PROG/CIM",5,32000,32500	as above but with entry address 32500

To access drives 1 through 7 add ":d" to the file name:

	@NEW":3"
	@LIST":2"
	@SAVE"PROG/BAS:4"

Errors are always indicated with ?FD ERROR.
Use ? PEEK(17396) to get the error code:

1	$01	Tape write protected.
2	$02	Drive not present.
4	$04	Checksum error.
8	$08	Parity error.
16	$10	Sector not found.
129	$81	Directory full, 32 files.
130	$82	Tape full or insufficient tape to save file.
132	$84	No file to save (BASIC file, no program in memory).
136	$88	End-Of-File encountered (tried to @GET a record that does not exist).
144	$90	Load file format error (tried to @LOAD or @RUN a data file or @RUN a
		machine language file without an entry address).
160	$A0	Insufficient memory (to load a BASIC file).
192	$C0	File not found in directory (wrong file name).
