its position. The ROMs as used in production machines are two surface mount chips located directly behind the CPU. Quadra 605s use a 1024 KB ROM, version 7C. PowerPC upgrades The Quadra 605 was compatible with Apple's Macintosh Processor Upgrade Card which provided a 50 MHz PowerPC 601 CPU. DayStar Digital and Sonnet manufactured 100 MHz versions of this card which could also be used in the Quadra 605. These upgrade cards plug directly into the 68040 socket, but when fitted cover the LC PDS expansion slot, making this slot unavailable for other expansion cards. Miscellaneous Some Quadra 605s have a Cuda reset switch which is used to manually reset the PRAM, located towards the rear of the motherboard just to the front of the audio out port and labeled "S1". Others do not include this switch, instead having two solder pads within a silkscreened square. The keyboard power-on key will not start up a Quadra 605 as there is no soft power-on. Only the rocker switch at the back will turn a Quadra 605 on or off. Pressing the power-on key while booted is the same as selecting the Shut Down command in the Finder, and once a Quadra 605 has completed its shutdown process it will prompt the operator to manually turn it off. Quadra 605s have no reset button or programmer's button, but key combinations can perform the same functions. To reset, users can hold down the Command, Control and Power keys. For a programmer's button click, users can hold down the Command and Power keys. There are some hard crash situations where even this is not enough to restore the system, in which case the power switch is the only recourse. A modified Quadra 605 motherboard was used as the basis of early Apple Interactive Television Box prototypes. Later prototypes used their own board design, but still retained a resemblance to the 605. Gestalt IDs The standard Gestalt ID for a 25 MHz Quadra 605 is 94. The ID of the logic board that the Quadra 605 shares with other LC/Performa models depends on two things. Jumper J18 (located just behind the hard drive) will identify the computer as a Quadra 605 (ID 94 @ 25 MHz) if it is ON, and as an LC475/Performa 47x (ID 89 @ 25 MHz) if it is OFF. Over-clocking and under-clocking the motherboard also changes the Gestalt ID. A