LBL "FACT"  ; Key: 12 
"FACTORIAL" 
AVIEW 
PSE 
FIX 00 
"N ?" 
PROMPT 
STO 00 
1 
STO 01 
LBL 21 
RCL 01 
RCL 00 
* 
STO 01 
RCL 00 
1 
- 
STO 00 
X#0? 
GTO 21 
RCL 01 
STOP 
END