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14
Fill Character Requirements
GEK-36143
PAPER TAPE VFU FILL CHARACTER REQUIREMENTS
Fill character requirements for the paper tape VFU unit are different from those required for the disc type VTFF
mechanism. This difference was created when the oscillator was slowed down from 8.4 ms to 10 - 10.5 ms to allow
use of forms up to 14 inches (35.6 cm) long. A strapping option is provided on the TVFA board (see Figure 8) which
allows use of the present fill character rules, but restricts the form length to less than 11 inches (27.9 cm). This strap
disconnects the oscillator, and connects the chip input to the TL signal on the mother board. The TL signal is not
present on TermiNet 300 A, B, or early C model Printer mother boards and the oscillator must be used if the paper
tape VFU is retrofitted onto these Printers.
The following table summarizes the possible arrangements.
TVFA
Setting of R31
Reference
Strap
on TVFA
J1 In
Not
Per VTFF (Manual GEK-36150, pp. 6-5 through 6-16)
J2 Out
Applicable
J2 In
10.0
Per VFU (This manual, pp. 14-16 and Figure 8)
J1 Out
10.5 msec
J2 In
8.3 msec
Per VTFF (Manual GEK-36150, pp. 6-5 through 6-16)
J1 Out
VFU FILL CHARACTER REQUIREMENTS WHEN USING TVFA OSCILLATOR
(SET AT 10 TO 10.5 MS)
TermiNet 300 PRINTER
Required time delay between
VT or FF command and first character
=
320 ms + (27 ms x number of lines)
Example:
At 30 cps, with two lines of VT
320 ms
+
(27)(2) = 374 ms required time delay
Converting to equivalent number of fill characters,
30 char/sec
=
33.3 ins/char.
Fill char. required = 374 ms ... 33.3 ms/char.
=
11.3 fill characters
= 12 fill characters (always round off to next higher number)
Alternatively, the following table may be used:
30 cps
15 cps
10 cps
I
Non-Printing
Fill
9.6
+
4.8
+
3.3
+
Characters Required
.81/line
.41/line
.27/line
Using the same example as above:
9.6
+
(2 Iines)(.81)
=
9.6
+
1.6
=
11.2 = 12 fill characters
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