SECTION
ONE
INTRODUCTION
The ADM-2 Interactive Display Terminal
is
a
microprogram-controlled device
that
provides a
means
of
communicating with aremote
computer
and can offer the user the ability
to
do some
limited independent processing
at
the display
area.
The terminal is acomplete self-contained unit.
Included within the terminal's lightweight hous-
ing
is
afan, cabling, and all required hardware.
The keyboard
is
housed in aseparate enclosure
but
can be
mounted
with the ADM-2 terminal,
if
desired. The ADM-2 terminal consists
of
four
main functional sections, which are:
•Cathode Ray Tube (CRT) display and
monitor
Circuit Board with microcontroller, memory
and logic
•Power Supply
•Keyboard with key encoding electronics.
Figure
1-1
illustrates the functional makeup
of
the ADM-2.
An
ADM-2
character page (full screen) contains
24 character lines, each with 80 character posi-
tions, providing atotal display capacity
of
1920
CRT
DISPLAY
LOGIC BOARD
WITH
MEMORY
KEYBOARD
characters
per
page. Display fields are refreshed
at
arate set by acrystal oscillator synchronously
with
60
Hz
input
power in the standard terminal.
This rapid refresh rate generates flicker-free images
and high contrast display even in bright light.
The ADM-2 transmits data
to
the
computer
(or
data
set) via astandard RS-232-C
data
interface.
The standard code for ADM-2 transmissions is
aten-bit asynchronous serial ASCII code with
even parity.
The ADM-2 can emulate an ADM-l by using
special sequence codes designated for this purpose.
When emulating an ADM-I, with aserial printer,
unformatted
print must be specified by the
program.
Optional equipment available with the ADM-2
include:
•Line Printer interface
•Polling interface
•20ma Current Loop interface
•RS-232-C Extended interface
•Optional word structures in addition
to
the
ten-bit code
•Composite Video.
INTERNAL
POWER
SUPPLY
Figure 1-1.
ADM-2
Functional Makeup
1-1
