1.Create a new document and then add a calculator application.Then press
undef+undef 
.Then you will receive an intenal error.Then your CAS+'s CAS is disabled.You will receive an "intenal error"again if you try to performance a calculation that requires CAS.You can remove your CAS+'s batteries and then put them back to make CAS works again.2.Create a new document and then add a calculator application.Then press
undef+undef .Then your CAS+ will hang at once.(But sometimes this does not work) 
3.Create a new document and then add a notepad application.Then press
undef+undef .Then select it with the mouse keys of CAS+ and select"Evaluate Expression"in the menu.Then press any key.Then the CAS+ will reboot.Then Create a new document and then add a calculator application.input rand() and then .The answer will be 0.99999.then save this document.Do these things again to make it reboot again,and open the document saved just then.Input rand() and then ,the answer is still 0.99999. 
Do these things again and again...The answer will always be 0.99999 .
PS:If you do these things on a MP version Nspire,you'll get only undef+undef*i as an answer.And if you do these things on a TI68K series calculator,you will receive "Error:Memory".So,this operation may cause an overflow or another error in CAS+'s memory,which causes the phenomenons above.
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