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SECTION VIII.
OPERATOR'S CONSOLE
return is specified by control character C3 of the PDT instruction.
Depending on the bit configu-
"'-"
ration of C3, carriage return may be effected or inhibited when the record mark in memory
which terminates the typeout (or parameter entry) is sensed.
If, however, the condition speci-
fied by.C3 is overridden by the right-hand margin control function, the right-hand margin control
takes precedence.
The program can effect single-line spacing by means of a PDT instruction which specifies
writing a record zero characters in length with carriage return.
In addition, the Carriage
Return key (which may be used by the operator at any time) also effects vertical movement of
the paper as well as carriage return.
Paper is moved vertically as long as the Carriage Return
key is held down.
All carriage return and line spacing operations produce text of three or six
lines per inch, depending on the manual adjustment of the typing mechanism itself.
Console Parameter Entry
Parameter entry may be accomplished in four steps:
1.
The operator is notified by the program that a parameter entry is required.
A PDT read instruction is issued to the console specifying (in the A address)
the data input address for the parameter.
As the PDT read instruction is
issued, the TYPE indicator on the console is illuminated, and the keyboard
bell rings once.
(If desired, a programmed typeout of the parameter re-
quest, i. e., a PDT write instruction, may precede the PDT read instruction. )
2.
The operator keys in the required parameter.
Each keystroke causes one
character to be printed by the console and the same character to be delivered
via the assigned read/write channel to the memory address specified in the
PDT read instruction in "I" above.
The operator continues striking keys
until a record mark is encountered in the data input area of memory.
When
the record mark is sensed or when the Carriage Return key is pressed, data
transfer is terminated (in the case of the Type 220-3 Console, an interrupt
signal is sent to the central processor if console interrupts have been allowed
by the program), the TYPE indicator is extinguished, and the typing mechanism
is disabled so that further keystrokes (except the Carriage Return key) are
not effective.
(The last character typed is placed in the location containing
the record mark.) In addition, programmed carriage return may be either
effected or inhibited at this point, depending on the bit configuration of control
character C3 of the PDT read instruction in "I" above.
3.
The program requests verification of the entry.
The program sends a second
PDT read instruction to the console requesting verification of the parameter
entry.
The keyboard bell again rings once and the TYPE indicator is il-
luminated.
(If desired, a programmed typeout of the verification request,
i. e., a PDT write instruction, may precede the PDT read instruction. )
4.
The operator confirms or cancels the entry.
The operator may either con-
firm or cancel the parameter entry by striking an appropriate key.
Any de-
sired character key may be designated by the programmer as the "confirm"
or "cancel" key.
It should be noted that steps "3" and "4" above may be eliminated by direct program
comparison of the parameter entry with a parameter vocabulary of limited size that is stored
in memory.
8-7
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