Miscellaneous
At the time of its release, many users noticed that performance suffered as a result of upgrading from System 6 to System 7, though newer hardware soon made up for the speed difference. Another problem was System 7's large "memory footprint": System 6 could boot the system from a single floppy disk and took up about 600 KB of RAM, whereas System 7 used well over a megabyte, and could no longer be usefully run from floppy-only machines without the aid of an external SCSI hard drive. (Versions up to 7.5 could boot from a floppy, but there would be no room for other applications, although it was possible to access an AFP server on an AppleTalk network.) It was some time before the average Mac shipped with enough RAM built in for System 7 to be truly comfortable. Offsetting this was the inclusion of a hard disk as standard in most Mac models sold at the time of System 7's introduction.
In order to take advantage of System 7's virtual memory feature, a Macintosh equipped with a PMMU is required. The Motorola 68030 CPU has one built-in, and one can be added to the motherboard of the 68020-equipped Macintosh II. The other Macintosh model using an '020, the Macintosh LC, cannot use virtual memory. Apple introduced the Macintosh LC II shortly after System 7's introduction. The LC II's main improvement over the LC was the ability to use virtual memory under System 7, as it retained the 16-bit bus and did not perform any faster than the LC it replaced.
System 7.0 was adopted quite rapidly by Mac users, and quickly became one of the base requirements for new software.
The engineering group within Apple responsible for System 7 came to be known as the "Blue Meanies", named after the blue index cards on which were written the features that could be implemented in a relatively short time. In comparison, the pink index card features were handled by the Pink group, later becoming the ill-fated Taligent project.
System 7.0 was the last version of the Macintosh operating system that Apple made available without charge and allowed to be freely redistributed. Although it could be purchased from Apple, the cost was nominal and considered to only cover duplication and media. It was perfectly legal to copy a friend's System 7 installation floppies, and it was common for Macintosh dealers to allow customers to use the store's demo machines to copy System 7 install disks for the cost of a box of floppies. CD-ROM magazines such as Nautilus included System 7 on their disks. After Mac users downloaded thousands of copies of System 7 from the online services (AOL, Compuserve and GEnie), Apple surveyed the services and based on this popularity started selling the Mac OS as a retail product with System 7.1. (System 7.5.3r2 is now available for free from Apple's web site, but was not posted until long after it had been superseded. A System 7.5.5 updater is also available for free download.)
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