Graph Mode - Tektronix 4010 Maintenance Manual

Installation and Operation-4010 Maintenance
the top-center of the display, in Margin 1 position. Enter
enough LINE FEED commands to again send the cursor
past the bottom of the display; it will re-appear at the top
in Margin
~
position. THE EFFECTIVE MARGIN CON-
DITION CHANGES EACH TIME THE DISPLA Y LlNE-
FEEDS PAST THE LAST (35TH) LINE.
Again arrive at the Margin 1 position and enter several
SP characters at the Space bar. Then enter CTRL M to send
a CR to the receiving circuits. Note that the cursor returns
to the effective margin position, in this case Margin 1. Now
enter enough characters to space past the end of the line.
Note that the cursor returns to Margin 1. CR, RETURN,
OR AUTOMATIC CARRIAGE RETURN SET THE
CURSOR BACK TO THE EFFECTIVE MARGIN
POSITION.
Press RESET to set Margin
~.
Now enter characters until
they cause spacing past the end of the line and subsequent
line feed and carriage return. Note that character writing
ignores Margin 1 position or Margin 1 information while
Margin
t
exists. If two-column formatting is to occur,
Margin
~
information must be kept to 36 characters or less.
View/Hold. Wait about 90 seconds and note that the
Terminal automatically enters a reduced intensity condition
referred to as Hold. This condition prolongs tube life, and
occurs in Alpha Mode only. Therefore, the Terminal should
always be placed in Alpha Mode when energized, but not in
use.
Graph Mode
Note the position of the Alpha Cursor. Then send GS
(CTRL SHIFT M) to the receiving circuits and note that the
Alpha cursor disappears. Send the address 383Y, 512X to
place the beam near the center of the screen. The required
bytes can be determined from Fig. 1·8 through 1-11. They
equate to
+
DE L
~
@
in ASCII code. Enter
+
RUBOUT
~
@
at the keyboard. (RUBOUT transmits DEL.)
Unwritten Vector. No obvious results occur in response
to the just·entered commands, because it is the first address
to be received after a GS, and the beam is blanked while the
movement occurs.
Written Vector. Enter
@
again. It will execute a second
vector, which will be written. This vector appears as a dot
near the center of the screen, since no change in position
was commanded. (The
@
contains the code for a Low X
byte, which causes vector execution.) Now send the address
for 32Y, 32X. This equates to SP DEL SP _ and is entered
at the keyboard as SP RUBOUT SP _ to draw the vector.
Note that nothing happens until the Low X (last) command
1-10
is-entered, but then a vector is drawn from the center to the
lower left corner.
Resetting With US. Now go back to Alpha Mode,
without otherwise disturbing the receiving circuits, by
sending a US to the Terminal. Do it by entering a CTRL
SHIFT 0 at the keyboard. Note that the Alpha cursor
appears with its lower left corner at the end of the vector,
since US causes no change in the Terminal position'register
contents. Now send ten SP commands to the Terminal by
pressing the keyboard Space bar. Note that the cursor
moves away from the end of the vector.
Graph Memory. Put the Terminal back in Graph Mode
by sending it a GS (CTRL SHIFT M). Then send the same
Low X command as was last used, by again entering _ at
the keyboard. The beam will move unseen back to the end
of the vector because of the Graph Mode memory circuits.
This can be confirmed by entering a second _ at the
keyboard, to again send the Low X command to the
receiving circuits. Note that the same Low X command as
contained in the last address must be used, or the beam
position will differ by the amount of difference between
the two Low X bytes.
Resetting With CR. Now switch from Graph Mode to
Alpha Mode by sending a CR to the receiving circuits. This
can be done by pressing the RETURN key or entering a
CTRL M at the keyboard. This places the Alpha cursor at
the left margin, in line with the last graphic position of the
beam.
Resetting With ESC FF. Send a GS to the receiving
circuits by entering a CTR L SH I FT M at the keyboard.
Enter two _ commands to confirm that the Terminal is
back in Graph Mode, and is at the end of the drawn vector.
Then send an ESC FF sequence to the receiving circuits. Do
this by entering CTR L SH 1FT K and then CTR L
L.
Note
that this erases the display, selects Alpha Mode, and homes
the Alpha cursor. This can also be done locally by pressing
the PAGE key, regardless of the position of the
LOCAL/LINE switch.
Resetting With RESET. Send another GS (CTRL SHIFT
M) to the receiving circuits, enter _ to return to the last
graphic address, and then draw a vector to 32Y, 1023X.
This translates to SP DEL ? _ which can be sent by
entering SP RUBOUT ? _ at the keyboard. Now press the
RESET key at the keyboard. Note that the Alpha Mode is
restored, and the Alpha cursor appears at the top left
corner of the screen. No erasing occurs. This particular
operation can only be accomplished from the keyboard. No
program command equivalent to RESET can be sent.
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