These are the initial set of ROMs that come in a Macintosh IIci. These chips are soldered to the board, so ROM updates and upgrades for the IIci will come in the form of ROM SIMM cards.
This set of ROM is 512KB. Previous members of the Macintosh II family have 256KB ROMs. The extra ROM space was needed because several Toolbox and OS managers have been rolled into these ROMs. Patches that have previously been in the System file have also been rolled into ROM. In preparation for the transition to a 32-bit environment, ROM code has been modified to work correctly under that new environment. Since the IIci also has new hardware components, extra code was necessary to manage those new components. Finally, numerous enhancements have been made to help optimize and generalize this ROM code. Specific changes to the ROMs include:
•32-Bit Addressing Support ("32-Bit Clean") - Currently, the Macintosh OS runs in a 24-bit world, where the hardware ignores the high byte of all memory addresses, which most software uses in the form of handles and pointers. Software that is capable of running in a 32-bit environment is said to be "32-Bit Clean". For more details on 32-Bit Cleanliness, see Macintosh Technical Note #212. Most of the code in the IIci ROM has been modified to be 32-Bit Clean. Macintosh System Software 6.0.4 is only a 24-bit environment, so this feature will not be put to use immediately.
•24/32-Bit Memory Manager - In order to handle a 24-bit and 32-bit environment, the Memory Manager had to be modified. This new version of the Memory Manager is in the IIci ROM.
•32-Bit QuickDraw - 32-Bit QuickDraw provides various extensions to Color QuickDraw. The most notable of which is the ability to support direct color devices and frame buffers greater than 1MB in all pixel sizes. 32-Bit QuickDraw has been rolled into the IIci ROM.
•Palette Manager - The Palette Manager provides routines that applications can call to manage shared color-look-up-tables, to provide exact colors for imaging, or to initiate color table animation. Various problems with the Palette Manager have prevented widespread use of this manager. These problems have been fixed in the latest version. This new version of the Palette Manager is also more careful to preserve and restore the color environment as applications launch and quit. This improves the performance of color applications, without developers needing to add special code. This new version of the Palette Manager has been rolled into the IIci ROM.
•Slot Manager - The Slot Manager contains routines that allow software to identify NuBus cards and communicate with the firmware on each card. An older version of the Slot Manager has been in previous Macintosh II family ROMs, but a newer version is incorporated in the IIci ROM. The newer version has been completely rewritten. Enhancements include the ability to:
-Enable or disable slot resources on the fly.
-Find out the current Slot Manager version.
•Script Manager - The Script Manager is a set of extensions to the standard Macintosh Toolbox and operating system that does two things:
-It provides standard tools for the sophisticated manipulation of ordinary text.
-It provides a standard method for translating an application into another writing system.
In Macintosh System Software 6.0.x, the Script Manager is installed with a system patch. In the IIci, the Script Manager has been rolled into ROM.
•Notification Manager - The Notification Manager provides a set of calls for applications to generate alerts or warnings when they are running as background tasks under MultiFinder. In Macintosh System Software 6.0.x, the Notification Manager is installed with a system patch. In the IIci, the Notification Manager has been rolled into ROM.
•Time Manager - The Time Manager has been improved to allow drift free timing. The Time Manager's resolution has also been increased to 20 microseconds. Previously, the maximum resolution that the Time Manager supported was 1 millisecond. This version of the Time Manager has been rolled into the IIci ROM.
•MDU / RBV / PGC Support -
Code was needed to support the functionality provided by each of these chips. This includes improved MMU setup, an improved ability to support varying RAM configurations and support for built-in video, which includes intelligent monitor sensing and auto-configuration. This code has been included in the IIci ROM.
•General Code Improvements - Several things were done to help optimize code in IIci ROM. This includes performance-based rewrites of many sections of the low-level operating system code and a greatly improved system for identifying ROM and system capabilities at run-time.
