Monitor Printer; Interrogating Typewriter - RCA 301 Programmer's Reference Manual

Ten characters are printed per horizontal inch and six lines per vertical inch.
In the Synchronous Mode, the Printer will print 26 letters of the English alphabet, the numerals (0 to 9),
and the following 11 punctuation marks and symbols for a total of 47 available characters.
CR credit
y
apostrophe
* asterisk
ampersand
&
In the Asynchronous Mode, the Printer will print 26 letters of the English alphabet, the numerals (0 to 9),
the above listed 11 punctuation marks and symbols, and the following 17 punctuation marks and symbols
for a total of 64 available characters:
@ at the rate of
percent
%
quote or ditto
"
subscript 10
10
open parenthesis
(
]
close bracket
For accuracy control, a printer unit inoperable alarm is incorporated which stops both the Printer and the
Computer. Also, by means of a micro-switch, the Printer can sense a "low paper' condition and send a
warning signal to the Computer.
When the Computer program calls for tape loop control of a page change and a "low paper" signal is
present, both the Computer and the Printer stop after accomplishment of the page change and the com­
pletion of any instruction in progress in any other mode, to permit replenishment of the paper supply.
Thus, printing on a page is completed before the operation is stopped.

MONITOR PRINTER

The Monitor Printer is a typewriter-like output device operated under program control. The Tape Write Normal
or Tape Write Simultaneous instructions are used for operation of this device. Characters can be printed at the rate
of up to 10 characters per second. Ten characters are printed per inch, 95 characters per line. Paper may be single
or multiple sheets, up to 11 inches wide. The following pica type characters may be printed:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
0123456789
# @ ( ) = : , % & E B ; E I $ " - . • + *
A carriage return is effected by printing an RCA 301 "ED" character or by setting tab stops.
The information is checked for correct parity in the Processor. If the Monitor Printer is inoperable when
addressed, a computer stop occurs.

INTERROGATING TYPEWRITER

The Interrogating Typewriter is an input/output device, operated under control of the stored program, which
allows interrogation of the computer files via a keyboard. The replies are received and typed by the same device.
The program staticizes the Tape Read Forward Normal or the Tape Read Forward Simultaneous instructions to
enter data into the computer. The Tape Write Normal or Tape Write Simultaneous instructions are used to write data
from the computer. The Input/Output Sense instruction is used to sense the status of the Interrogating Typewriter.
II-4
virgule
/
a
lozenge
minus
—
+
plus
:
colon
#
number
semicolon
J
>
greater than
divide
- 7 "
up arrow
f
E D E F / '
(SP) space
, comma
period
dollar sign
$
) close parenthesis
[
open bracket
<
less than
=
equal