Technical Q&As

Q What are the 'mach' Gestalt values for the recent Macintosh models?

A Recently, we announced the following new Macintosh model:

Macintosh PowerBook G3 Series

The following list includes the 'mach' Gestalt selectors for these and other Macintosh systems which are not included in the Gestalt.h header file which is part of the Universal Interfaces 3.1. In a previous version of this Q&A, the list of Macintosh models was longer. This list is shorter since it does not include those Gestalt selectors now included in the Gestalt.h header file (which is part of the Universal Interfaces 3.1).

gestaltPowerBookG3Series = 312; { Macintosh PowerBook G3 Series }

gestaltPowerBookG3 = 313; { Macintosh PowerBook G3 }

gestaltPowerBookG3Series2 = 314; { Macintosh PowerBook G3 Series }

gestaltPowerMacG3 = 510 { Power Macintosh G3 }

gestalt20thAnnivMac = 512; { Twentieth Anniversary Macintosh }

Note 1: To distinguish the Twentieth Anniversary Macintosh from the Power Macintosh 5500, make a secondary Gestalt selector call to the selector 'bxid'. The response for a Twentieth Anniversary Macintosh will be 0x0000302B.

Note 2: As per the developer note for the Macintosh PowerBook G3 Series, there are 2 machine ID's associated with these models. The developer note, dated 5/6/98, indicates that the difference between the two machines lies with the screen size. The true difference is that the Powerbook with machine ID 314 is limited to 2MB of SGRAM. (There is no expansion slot on the 314 system to upgrade video memory.) It may appear that another difference would be that the 314 system has no backside cache and runs only at 233MHz; however, these are functions of the processor card which is independent of the motherboard.