ACT apricot - Page 234

INTRODUCTION
The standard Display Unit is a 9 inch high resolution
(400lines) monochrome (green on black) display monitor,
which fits onto the shallow recess on the top of the System
Unit. The unit tilts and swivels, enabling the operator to
position the screen to obtain the optimum viewing angle.
To minimise the possibility of operator eye fatigue:
(a) The screen incorporates a long persistence phosphor
(P39) to reduce display flicker.
(b) An anti-reflective mesh is fitted over the screen to
reduce glare.
Display brightness is adjusted by a
manual control
located
next to the recessed carrying handle on the rear of
the unit.
DESCRIPTION
General
The display is controlled by the CRT circuitry on the
System Board, which generates a serial video signal and two
sync signals (HSync and VSync to control the movement of
the electron beam accross the screen). The amplitude of the
video signal is approximately 0.3 V when operating in
normal intensity, 0.4 V in high intensity. The sync signals
are positive TTL.
The + 12V supply voltage for powering the monitor is also
supplied from
the System Unit. A 1.0 amp fuse is located
internally within the Display Unit.
The CRT control circuit is programmed to produce an
interlaced picture on the screen operating at a field rate of
approximately 72 Hz and a line scan rate of 15.79 kHz.
The Display Unit is connected to the System Unit via a
6-wire cable
assembly terminating in a 9-pin female D-type
connector.