From: ohland@charter.net   
      
   On the IBM 4216-03X printers, these default emulation modes are stored   
   in a Non-Violatable Random Access Memory (NVRAM). These relatively   
   expensive chips have the advantage of keeping their content even when no   
   power is available to them. Unfortunately, the maximum write/read cycle   
   count is relatively limited. It may only be good for 5000 cycles or   
   less. Therefore, constantly switching the emulation modes may not be the   
   best idea in the long run, because it may be necessary to repair the   
   printer if the NVRAM doesn't work any more.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)