Developer Documentation
PATHHardware Documentation > Original Power Mac G3 Computers Developer Note


Machine Identification

All of the Power Macintosh G3 computers have a machine ID value of 510 (hexadecimal 1FE). Applications can find out which computer they are running on by using the Gestalt Manager routines. Inside Macintosh: Overview describes the Gestalt Manager and tells how to use the gestaltMachineType value to obtain the machine name string.

It is possible to get the ROM subversion value to determine if the logic board is the original Power Macintosh G3 logic board with the V4.0 F2 ROM or an enhanced logic board with the V4.5 F1 or V4.5 F2 ROM. The following prototype example code can be used to get the ROM subversion number of the Power Macintosh G3 logic board.

#include <LowMem.h>
.
.

UInt16 GetROMSubversion(void)
{
    return *(UInt16*)((UInt32)LMGetROMBase() + 0x12);
}

Modem Slot

The modem slot in the Power Macintosh G3 computers is not a PCI bus compatible communications slot (comm slot II) like the comm slot in the Power Macintosh 5500 and 6500 computers. The modem slot is strictly for modem cards that do not require the use of the PCI signals. The modem slot is located on the Apple DVD-Video, Audio/Video, and Audio input/output cards rather than on the main logic board, as it is on previous Macintosh models that include a comm slot.

Expansion Slots

The three I/O expansion slots are PCI expansion slots that conform to the PCI V2.1 specification.


© 1998 Apple Computer, Inc. - Revised 8/13/98