The Macintosh IIci was not only the first Macintosh with a higher
clockspeed and built-in video, it was also the first system with 32 bit
QuickDraw in ROM and the first system to utilize non-contiguous memory and
the PMMU for memory addressing. These were all significant internal
modifications, intended to strengthen the Macintosh architecture and
provide even greater flexibility for future hardware and software
developments.
The majority of the modifications that third-party developers had to
make to support the Macintosh IIci were changes that were necessary to
support future CPUs and future versions of the Macintosh operating system.
- Addressing changes necessary to support non-contiguous memory and the
utilization of the PMMU were changes that would be required to run
correctly with VM in System 7.0.
- 32-bit QuickDraw will be built into all future ROM's which offer color
support.
- The Built-in video monitor identification scheme will be built into
future CPUs and is also part of our new video cards.
- Changes to the ADB manager and the video configuration (i.e. gamma
correction table) will both be included in future systems.
- And, the fact that Apple will design systems that run at greater than
16Mhz is obvious.
For more information, see the four-part article on Macintosh IIci
compatibility problems.