Specifications

CHAPTER 1
Introduction
12 Compatibility Issues
IMPORTANT
The JEDEC MO-161 specification shows three possible heights for the
8-byte DIMM. For Power Macintosh computers, developers should use
only the shortest of the three: 1.100 inches. Taller DIMMs put excessive
pressure on the DIMM sockets due to mechanical interference inside the
case. ▲
Cache Expansion 1
On the Macintosh Performa 6400 computer, the optional 256K L2 cache includes an
integrated cache controller. Apple does not support development of third-party cache
cards for these computer models. The 160-pin cache expansion slot is the same as the
cache expansion slot in the Power Macintosh 5400.
ATA (IDE) Hard Disk 1
The internal hard disk in the Macintosh Performa 6400 computer is an ATA (IDE) drive,
not a SCSI drive. This could cause compatibility problems for hard disk utility programs.
The system software release for the Macintosh Performa 6400 computer includes version
3.0 of the ATA Manager and supports PIO, singleword DMA, and multiword DMA data
transfers. For more information about the software that controls the ATA drive, see the
Power Macintosh 5400 Developer Note.
Sound I/O Specifications 1
The sound specifcations for the built-in sound ports on the Performa 6400 are:
■ 16-bit stereo output featuring SRS 3D surround sound technology
■ sample rates of 11.025, 22.05, and 44.1 kHz
■ input line level: 2 Vpp max. into 10 kilohms impedence; signal to noise ratio 75 dB, 80
dB typical (A-weighted, 2 Vpp output, 1 kHz, digital record and playback, sound
input port to sound output port, with SRS disabled)
■ frequency response: 20 Hz-18 kHz (-3dB relative to 1 kHz under the same conditions
as the SNR (signal-to-noise ratio) measurement)
Power Supply 1
The power supply in the Macintosh Performa 6400 computer is not self configuring for
different input voltages. The voltage switch on the Performa 6400 computer is delivered
preconfigured for the input voltage of the region in which the unit is originally
purchased. If the computer is moved to another location where the input voltage is
different, a voltage switch must be adjusted to accomodate the voltage change. The
switch has two positions that support voltage ranges of 100 to 130 V or 220 to 270 V.