During most Applesoft routines the descriptor is left in memory, while a two byte pointer to the descriptor is kept in the FAC. The pointer is the address of the descriptor; therefore, the actual string could be anywhere in memory. The statement 10 A$ = "HI" leaves a descriptor pointing to the program text.
STRINI ---- E3D5
STRINI obtains space for creating a string whose descriptor is pointed to by FACMO/FACLO; it also creates a descriptor for it in DSCTMP. On entry A = length of the string, while FACMO/FACLO point to the string descriptor.
STRINI uses GETSPA to force garbage collection when there isn't sufficient room; GETSPA exits with an "OUT OF MEMORY ERROR" when garbage collection free up enough room. GETSPA moves FRESPC and FRETOP down, making room to store the string. STRINI returns with the descriptor of the new string in DSCTMP and the original pointer in DSCPNT.
STRSPA ---- E3DD
STRSPA obtains space for the creation of a string A bytes long, then creates a descriptor for it in DSCTMP. STRSPA uses GETSPA to force garbage collection when there isn't enough room. If garbage collection is unable to make sufficient room, GETSPA exits with an "OUT OF MEMORY" error. GETSPA moves FRESPC and FRETOP down enough to store the string, then returns A unchanged with the new descriptor in DCSTMP.
GETSPT ---- DA7B
GETSPT moves the descriptor pointed to by FACMO/FACLO into the memory pointed to by FORPNT. GETSPT also moves the string's text up to FRETOP if it isn't in the program's text. GETSPT frees up the string if it was a temporary string. GETSPT uses GETSPA to initiate garbage collection, or alternatively "OUT OF MEMORY" error when the garbage collection dosen't free up sufficient room.
MOVINS ---- E5D4
Moves the string whose descriptor is pointed to by STRNG1 to memory pointed to by FRESPA.
MOVSTR ---- E5E2
MOVSTR moves the string pointed to by Y,X with a length of A to memory pointed to by FRESPA.
STRTXT ---- DE81
Build a temporary descriptor for a string literal of which the first character is pointed to by TXTPTR plus C and which ends with a quote. FACMO,FACLO points to the resulting temporary descriptor. Skip leading quotes before calling STRLIT. On exit, STRNG2 points to the character after the string literal.
STRLIT ---- E3E7
Build a temporary descriptor for a string literal of which the first character is pointed to by Y,A and which ends with a quote. FACMO,FACLO points to the resulting temporary descriptor. Skip leading quotes before calling STRLIT. On exit, STRNG2 points to the character after the string literal.
STRLT2 ---- E3ED
Take a string literal of which the first character is pointed to by Y,A and build a temporary descriptor for it pointed to by FACMO,FACLO. Save in CHARAC and ENDCHR the characters other than zero that terminate the string. Skip leading quotes before calling STRLIT2. On exit, STRNG2 points to the character after the string literal.
PUTNEW ---- E42A
Move the descriptor in DSCTMP to a temporary descriptor, put a pointer to the descriptor in FACMO,FACLO, and flag the result as a string.
GETSPA ---- E452
Get A bytes of memory below HIMEM for a string. GETSPA forces garbage collection to make room in memory when necessary and
exits with an "OUT OF MEMORY ERROR" if garbage collection can't make enough room. GETSPA moves FRESPC and FRETOP down enough to store the string. On entry, A equals the number of characters. GETSPA returns with A unchanged and pointer to the space in FRESPC, FRETOP, and Y,X.
FRESTR ---- E5FD
Make sure that the last FAC result was a string and free up the temporary string result. Check the descriptor for a temporary status allocated by PUTNEW. On exit, the address of the string is in INDEX and Y,X. The length of the string is in A. Uses FRETMP.
FREFAC ---- E600
Free up the temporary string pointed to by FACMO,FACLO. Check the descriptor for a temporary status allocated by PUTNEW. On exit the address of the string is in INDEX and Y,X. The length of the string is in A. Uses FRETMP.
FRETMP ---- E604
Free up a temporary string. On entry the pointer to the descriptor is in Y,A. Checks the descriptor for a temporary status allocated by PUTNEW. If so, the temporary is freed up by updating TEMPPT. If a temp is freed up, a further check tests the string's location for the lowest in memory. If so, that area of memory is freed up by updating FRETOP. On exit the address of the string is in INDEX and Y,X. The length of the string is in A.
FRETMS ---- E635
Free the temporary descriptor without freeing up the string. On entry Y,A point to the descriptor to be freed. On exit Z is set if anything was freed.