 |
|||
|
|
|||
| ||||||||||
|
|  MIL-D-81347C(AS)
Character Generator - The character generator shall utilize the
3.5.4.4.3.3.4
dot method to generate 44 possible characters. A six-bit counter shall generate a pattern of 8 by 8
dot positions through the use of two three-bit D/A converters. The six-bit counter shall also generate
timing pulses, which when gated through fixed wired character select gates, enable the video signal to
select a desired dot in the pattern. The selected dots comprise the desired character. Figure 146
illustrates the dot method of character generation.
Display Synchronization - A 40 Hz synchronization (Sync) pulse
3.5.4.4.3.3.5
generated by the ADL shall synchronously initiate the ADL in order to insure a jitter free display.
When this occurs the logic shall transmit an ODR and an EI to the DMS. If enabled in the DMS the
ADL EI will be transmitted to the computer. The computer may then select DMS output channel 2
and transmit output data to the ADL in response to an ADL ODR. Normal operation shall continue
until an EOD at which time the ODR shall remain at a logic "0" until the next cycle of the 40 Hz sync.
Sync Control - The ADL shall generate 40 Hz sync pulses continu-
3.5.4.4.3.3.5.1
ously when the DMS is not in a test mode. With the DMS in an MCP test mode, the sync generation
shall be under the control of the MCP sync switch. The sync switch shall dictate to the ADL whether
.
to generate 40 Hz sync pulses:
(1) Continuously
(2) Singularly
(3) None
Circle and Vector Generation - Circle and vector generation
3.5.4.4.3.3.6
shall be performed by logically controlling the phase and amplitude the X and Y output signals. A
sine- cosine generator shall provide a 12 KHz modulation source which shall operate in conjunction with
the X and Y conic D/A converters to obtain amplitude modulated square waves. Square wave signals
shall then be passed through low-pass filters to obtain amplitude modulated sinusoidal functions.
Type Mode - The ADL shall generate, under computer control,
3.5.4.4.3.3.7
a sequence of characters which shall represent a typewriter page. This mode of operation shall re-
quire the computer to generate a series of code 04 w orals, each word consisting of two character codes.
The ADL shall automatically increment its X Gross Position Register such that the characters are on
1/4 inch spacing. The incrementing shall continue until the computer sends a new Set Position word or
EOD word. If the computer fails to terminate the X deflection incrementing, the ADL shall auto-
matically cease incrementing when the X gross position register reaches its maximum deflection state.
Test Modes - The ADL operation shall be verified by utilizing
3.5.4.4.3.3.8
the MCP for synthesis of various computer command words. The MCP shall provide simulated com-
puter output words in three different operating modes:
(1) Single - The MCP shall transmit a manually programmed
one output word when the operator depresses a momentary switch.
(2) Repetitive - The MCP shall continuously transmit a manually
programmed word at the ADL's maximum rate for the function specified in the data w oral.
(3) Synchronous - The MCP shall output a manually programmed
word at a fixed rate of 40 Hz which shall be locked to the 400 Hz line.
Initialization - The ADL shall be self initializing, i. e., when
3.5.4.4.3.3.9
power is applied, no logic "1" shall be transmitted on the ADL control lines to the DMS and the ADL
shall be ready for normal operations. The ADL shall also initialize at the 40 Hz sync pulse time.
Interface Requirements - See functional flow diagram, Figure
3.5.4.4.3'4
139.
245
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals