The External Video Port drives video devices with a digital signal. It
does not provide an analog signal used by a monitor.
Display Electronics
-------------------
The display uses a digital signal to generate information, not an analog
signal like a CRT. There are three signals generated in the video logic
IC:
- the pixel synchronization signal; it marks the end of a byte.
- the horizontal synchronization signal; it marks the end of a 640 pixel
line.
- the vertical synchronization signal; it marks the beginning of a new
video frame.
The Macintosh Portable produces signals for an external video display
through an 8-bit interface that is similar to the interface for the
built-in display. A video adapter is required to convert the 8-bit data
stream into a signal that can drive an external video device.
Connector: Density and 1/2 15-pin (same size as DB-9 with 15 pins)
PINOUTS
1 - FPDATA(0) Data bit 0
2 - FPDATA(1) Data bit 1
3 - +5 volts **
4 - FPDATA(2) Data bit 2
5 - FPDATA(3) Data bit 3
6 - FPDATA(4) Data bit 4
7 - GND Signal Ground
8 - +5 volts **
9 - GND Signal Ground
10 - FPDATA(5) Data bit 5
11 - FPDATA(6) Data bit 6
12 - FPDATA(7) Data bit 7
13 - BATT_VOLTAGE
14 - FLM from Video chip, Begin frame scan over
15 - CL2/ from Video chip, Byte clock
** Maximum current on 5 volt line is 50ma