> #FFFF 1 + .                                                                     
0                                                                               
> /c .                                                                           
1          // correct                                                                           
> /c .   // its been sent to screen, not reset like stack                                                                        
1                                                                               
> /c a!  //save
                                                       
> /c.                                                                           
1         // error, should be 0                                                                      
>  

or 
> /c 1 + .
2
> /c .
1
// its not cleared

issue 2
/c carry not set when shifting { or } when bit overflows
> /c.                                                                       
0                                                                          
> #FFFF { /c.                                                               
0                                                                              
> #FFFF } /c.                                                             
0                                                                           
>     

- this is working as expected /r

> #FFFF #FFFF * /c. /r.                                                         
0 -2  // seems ok 
>    
> 23 44 * /r.                                                                   
0   // r has reset correctly