Specifications

CHAPTER 3
I/O Features
Built-in Video 33
Note
The user must hold down a key combination for at least 1 second to
allow the ADB microcontroller enough time to respond to the NMI or
hard-reset signal. ◆
Note
The NMI function can always be activated from the keyboard. This is a
change from the Macintosh LC computer, where keyboard activation of
the NMI function can be disabled by the software. ◆
Built-in Video 3
The built-in video circuitry supports pixel display sizes of 512-by-384, 640-by-480,
800-by-600, 832-by-624, and 1024-by-768. When power is applied, the monitor is initially
set for a display size of 640-by-480 pixels. The user can switch the monitor resolution on
the fly from the Monitor BitDepth and Monitor Resolution modules in the Control Strip
or the Monitors and Sound control panel.
External Video Connection for the Macintosh Performa 6400 3
The Macintosh Performa 6400 computer requires an external monitor. The cable from the
external monitor plugs into a standard DB-15 video port located on the upper-left part of
the enclosure’s rear panel. The pin assignments for the external video connector on the
Macintosh Performa 6400 are shown in Table 3-9.
Table 3-8 Reset and NMI key combinations
Key combination Function
Command-Power (x-p) NMI (always active)
Control-Command-Power (Control-x-p) Reset
Table 3-9 Pin assignments for the external video connector
Pin number Signal name Description
1 RED.GND Red video ground
2 RED.VID Red video signal
3 /CSYNC Composite synchronization signal
4 SENSE0 Monitor sense signal 0
continued