Texas Instruments TI-83 Plus Manual page 60

50
Decreasing the data size
DelMem
For example, delete 10 bytes at the beginning of an existing AppVar. If the AppVar
does not exist or if it is archived, CA = 1 is returned.
Delete_10:
;
;
;
;
AppVarName:
See the System Routine Documentation for details on DelMem.
TI-83 Plus Developer Guide
Decreases the size of an existing variable by removing data at a given
address.
LD HL,AppVarName
B_CALL Mov9ToOP1
B_CALL ChkFindSym
RET C
LD A,B
ADD 0FFh
RET C
PUSH DE
INC DE
INC DE
LD HL,10
EX DE,HL
B_CALL DelMem
POP HL
PUSH HL
B_CALL ldHLind
LD BC,10
OR A
SBC HL,BC
EX DE,HL
POP HL
LD (HL),E
INC HL
LD (HL),D
OR A
RET
DB AppVarObj,'AVAR',0
Chapter 2: TI-83 Plus Specific Information
; OP1 = name of AppVar
; DE = pointer to data if exists
; ret if not found
; archived status
; if archived then CA = 1
; ret if archived
; save pointer to size bytes of
; data
; move DE past size bytes
; number bytes to insert
; HL = pointer to start of delete,
; DE = number bytes
; delete the memory
; HL = pointer to size bytes
; save
; HL = old size of AppVar,
; number bytes
; decrease by 10, amount deleted
; DE = new size
; pointer to size bytes location
; write new size.
; CA = 0
Third Release May 28, 2002