Shift Key; Timing - GE TermiNet 300 Programmer's Manual

GEK-J5002 Programmer's Manual
1. SHIFT KEY
There are two large keys labeled SHIFT on each
side of
the keyboard. These keys operate very simi-
la r to a
nOI'Inal typewriter shift key. On the alpha-
betic keys,
the
SHIFT key is the difference between
lower case
and
upper case. On the other keys where
there are two symbols, the SHIFT key determines
whether the lower or upper symbol will be printed
and/or transll1itted. There are obviously some keys
on the keyboard which will not be affected by the
shift key. These keys are the keys labeled FF, HT,
VT, CTL, LOK, ESC, BS, RPT, DEL, RETURN,
LF.
2. lOK
The LOK key provides a mechanical function only.
That is, locking the shift key in the SHIFT position.
When depressed, the LOK key will stay depressed
until released by the SHIFT key directly below it.
This is the only key that releases the LOK.
3. RPT
The REPEAT key causes any key which is de-
pressed to be repeated at the rate of approximately
five characters per second.
4. BS
The BACKSPACE key generates the backspace
"BS" code shown in the USASCII chart. The Termi-
Net 300 Printer logic recognizes this code to move
the printing one position to the left. If the tape
punch is on, the BS code will be punched, but the
punch will not be backspaced.
5. DEL
The DELETE key is used to generate the DEL
code in the USASC II chart.
6.
HT
The HORIZONTAL TABULATION key generates
the HT code in the USASCII chart. The tabulation
feature will be discussed later as an option.
7. FF
The FORM FEED key generates the FF code
sho\vn in the USASeII chart.
8. VT
The VERTICAL TABULATION key generates the
VT code in the USASCII chart.
9. RETURN
The RETURN key on the right-hand side of the
keyboard generates the CR code in the USASCII chart.
12
If the A UTOMA TIC LINE FEED switch is in the ON
position on the front panel of the TermiNet 300, two
codes will be generated when the RETURN key is
pressed. These two codes are CR and LF, in that
order. The codes are generated with the one key-
stroke being the only operator motion necessary.
The effect of the CR code on the printer mechanism
will be to return printing to the No.
1
position. The
only exception to this is when the tabs have been
set~
then, the C R code will move printing to the tab
close~t to the No.
1
print pOSition.
10. LF
The LINE FEED key generates the LF code in
the USASeII chart. The effect of the Line Feed code
on the printer is to advance the paper one line for
each code. If the LINE FEED switch on the front
panel of the TermiNet 300 is set in the No. 2 posi-
tion, then double spacing will occur.
11. eTl
The CONTROL key modifies the bit configuration
of other keys. Commonly used non-printing codes
which are generated by using the COl.JTROLkey are
labeled on the front face of alphabetic keys used;
i. e., if you depress the CONTROL key and then
press the Q key, you will generate the USASCII code
DC 1 (reader ON). The CONTROL key then has, in
effect, modified the normal bit configuration of Q to
provide the non- print DC 1. Any of the non -print
control codes can be generated by depressing the
appropriate alphabetic key simultaneously with con-
trol, but only the most commonly used codes are
labeled on the front face of the key button.
12. ESC
The ESCAPE key does not operate in the same
manner as the CONTROL or SHIFT keyo The ES-
CAPE key is color coded with a maroon bar, and is
easy to correlate with other keys which are also
color coded. Whenever the ESCAPE key is depressed
and another key is then depressed, two characters
are automatically generated. The first of the two
characters is the USASCII code ESC, and the second
character is the character of the second key being
depressed. Two code sequences are used for sev-
eral functions in the TermiNet 300 Printer. In all
cases, to generate these two code sequences, the
keyboard operation is to depress the ESCAPE key
and then the appropriate second key to accomplish
the function desired. In each case, two codes will
be generated, with the ESCAPE code being the first,
imm ediately followed by the code of' the second key
depressed.
TIMING
Table 3 represents the basic timing of the Te rIni-
Net 300 Printer.