Technical information

1.1.1 Display Modes
Displays receive separate red, green, and blue analog signals through the
signal cable (75 ohms impedance). Separate, non-interlaced, horizontal
and vertical synchronization signals are also received through the signal
cable.
The polarity of the synchronization signals controls the modes of
operation. Modes of operation set vertical frequencies to vary the
maximum number of lines that can be displayed. The number of lines
displayed creates screen resolution. Each display can be used in three to
six operating modes. The modes are dependent on the display and the
computer system that the display is connected to. The polarities and
operating characteristics of the four primary modes are shown in the
following table:
+------------------------------------------------------------------------+
¦ ¦ Mode 1 ¦ Mode 2 ¦ Mode 3 ¦ Mode 4 ¦
+------------------------------+----------+---------+----------+---------¦
¦ Horizontal synchronization ¦ + ¦ -- ¦ -- ¦ + ¦
¦ signal ¦ ¦ ¦ ¦ ¦
+------------------------------+----------+---------+----------+---------¦
¦ Vertical synchronization ¦ -- ¦ + ¦ -- ¦ + ¦
¦ signal ¦ ¦ ¦ ¦ ¦
+------------------------------------------------------------------------+
Displays with only three operating modes have mode 4 reserved. Displays
with more than these four modes use interlaced horizontal and vertical
synchronization signals to create additional modes. The 8517 display has
two mode 4s available; the program providing the mode automatically
selects one of them, depending on the adapter in use.
The IBM Personal System/2 Color Displays Test-Pattern Diskette examines
the mode configuration from the monitor and the type of computer being
used and displays the modes available for the monitor.
PS/2 Displays Maintenance Manual
Display Modes
¦ Copyright IBM Corp. 1993
1.1.1 - 1