8025 Crt Terminal Specifications - Omron 8025G Maintenance Manual

GENERAL INFORMATION
SECTION 1
Nearly all operations in the terminal are controlled by the CPU
accorqf'~
to instructions stored in the program memory. Typical operation is briefly
desc~e
in the following paragraphs.
The CPU periodically polls the I/O cards and other functional modples on
the bus to find whether any are ready to send or receive data. Assume the keyboard
has data for the CPU. The keyboard intercepts a poll and identifies itself to the
CPU. The CPU then enters the keyboard routine in program memory and enables the key
board to transfer the data.
Following program instructions, the CPU processes the data. If the data
is a character for display, the CPU determines where the next character is to be dis
played and stores it at that location in the refresh memory. The refresh memory can
then supply the data to the CRT display. If the data is a function code (e.g.,
carriage return), the CPU executes the instructions to move the cursor to the start
"#
of the line in refresh memory.
A data transfer from an I/O interface is performed in the same manner. In
this case, the interface intercepts the poll and identifies itself to the CPU. The
CPU enables the transfer and processes the data as if it came from the keyboard.
Assume the CPU has data for the interface. The CPU addresses, enables, an
sets"
up
the interface for the transfer. When the interface responds to the next
poll, the CPU places the data on the bus for the interface.
1.2
SPECIFICATIONS
1. 2.1
Standard Terminal Specifications
Specificati'ofls for the 8025 CRT Terminal are given in Table 1-1.
Table
1-1.
8025 CRT terminal specifications
PARAMETER SPECIFICATION
8025 CRT Display
Screen Size
Safety 'Glass
Phosphor
Deflection Angle
Re
fresh Rate
Resolution
Nominal 8" x 10", 15" diagonal.
Integral part of CRT face.
P4 (white, medium persistence).
60 Hz.
1,000 TV lines at 40 fL, center.
800 TV lines at 40 fL, corner.
0.010" diameter spot at center.
1-4
(l
o