Table of Contents
PROGRAMMING THE PAPER TAPE READER
The paper tape reader reads at a continuous rate of 300 characters per second. Tape can be
read under program control or hardware control, depending upon the format in which it is punched.
Paper tape punched in the hardware load format is always read at the maximum 300-character-
per-second rate under automatic control of the DATANET-30 circuitry. The paper tape reader
is always on buffer selector address 0.
Paper tape may be read under program control in two modes, continuous mode and step mode.
Five- to eight-level tape may be read but normally only eight-level tape will be used.
If
paper
tape is read in continuous mode, the character under the read station must be taken away 500
microseconds after the flag is set.
If
the 500 microsecond timing restriction is not met, reading
must be done in the step mode at a speed of approximately 50 characters per second.
In either mode, when the sprocket hole is detected,
th~
character under the read station causes
the receive flag to be set.
When the character is taken away, the flag is automatically reset
and the reader moves the tape to the next character. This control of the movement of tape is
in effect at both 300 and 50 characters-per-second speeds. The sprocket hole serves as a timing
source. A sprocket hole only indicates a character and will set the receive flag.
The reader is turned on by the POWER ON switch on the paper tape reader control panel. Normal
operation requires that the reader be turned on at all times.
Reading Paper Tape Under Program Control
PAPER TAPE READER INSTRUCTIONS
Following are the paper tape reader instructions:
Register Transfer (From R, _ _ )
The character contained in the buffer is transferred to register A or B, as in the diagram below.
The receive flag and data buffer are reset.
If
stopped, any register transfer instruction from R
•starts paper moving or allows the movement of paper to continue.
18
6
5
4
3
2
1
To A or B
Input Buffer
"O"
t
Channel 1
Sprocket
1
0000.0001
Channel 8
[ID!A\11&~~11~ ~@------------
V-52
Table of Contents
