The Mac Admin's Blog

I remember an issue reported by a user last week who complained that his Mac asked for DVD region code multiple times for the same disc. This was in fact a PRAM or NVRAM issue. The user who called in was on iMac 27” so it was NVRAM which I had to fix. For readers who are not sure what NVRAM and PRAM is, can refer to my last post : What is PRAM and NVRAM . As we know that information regarding DVD region setting is saved in NVRAM of an iMac, so all I had to do is reset the NVRAM by pressing Command+Option+P+R before the grey screen appeared during the start up. Just by this small step, the issue was resolved.

Any person using Mac OS X machine might have heard of the term PRAM or NVRAM. These both are similar things, the only difference is that in Power PC based Mac machines it was termed as PRAM which stands for Parameter Random Access Memory and NVRAM is Non Volatile Random Access Memory which is in iMacs. What is the purpose of PRAM or NVRAM? The main purpose of PRAM or NVRAM is to save some settings related to hardware or software related to the system. In iMacs these are Screen resolution, display settings, video and screen refresh rate, recent kernel panic information (if there is any recent one), DVD region settings. How PRAM or NVRAM works? In an intel based MacBooks NVRAM takes power from the backup battery, however in other models it takes little (trickle) power from the main source to store data. The information saved in PRAM or NVRAM are: Display and video settings such as refresh rate, Screen resolution Number of colors Startup volume choic...