When you powered on a Cisco 3660 with this image, you were greeted by the Cold War-era reliability of the bootstrap code. The fans would whirr to life, and the console would spill out the familiar hash marks ( ##### ) as the image decompressed.

Here’s a structured write-up based on the identifier you provided:

: This describes where the software runs and how it is stored. "M" means it runs from RAM, and "z" indicates the file is compressed. : This is the version number (