Centronics 101AL Technical Manual page 199

This signal listing is keyed directly to the 1O1AL printer schematic drawings.
those drawings are listed alphabetically with their source and destinations.
APPENDIX A
SIGNAL GLOSSARY
All signal mnemonics contained on
The following notation is used to identify the source and destination locations: 5-13/24-2 signifies element ME5,
pin 13 located on schematic 63015124, sheet 2.
clock data from the input device
to the printer logic.
SIGNAL Komurt vou yeh 2a
NAME DESCRIPTION SOURCE DESTINATION
ACK Acknowledge - A 2.5-5.0 usec pulse 5-13/24-2 P5-Z/24-1
used to indicate completion of the
input of a character or end of a
functional operation.
BELL A 1 to 2-second pulse used to pro- 5-39/24-2 R56/24-3
duce an audible tone in the optional
speaker located at the rear of the
printer.
BUSY Status signal indicating to the input 5-11/24-2 P5-C/24-1
device that the printer is not ready 20-1/03-1
to receive data.
CG1-CG7 Seven signal LINES from the character ME1 & ME7 P4-P,R,S,1,
generators to the driver board, which U,V iW
| fire print wires 1-7.
CHADD7 Character address line 7. 6-2/24-3 20-16/24-4
cIP Carriage in Print - Signal used to 6-12/24-1 P9-12/75-1
drive the print head forward.
CIPX Carriage in Print - Signal from LSI 9-30/24-2 10-1/24-1
chip #2, command to turn on forward
clutch.
CLKTB1 Clock pulse used to clock input data 5-14/24-2 6-11/24-3
into memory register. Used for
loading data only.
CLKTB2 Clock pulse used to shift memory. 9-36/24-2 6-9/24-3
Not used when loading data.
CSBSY Cause Busy - Command from LSI chip 2 9-35/24-2 5-10/24-2
to LSI chip 1 to cause a busy con-
dition, when dummy character is de-
tected at memory output.
CSLF Cause Line Feed - Line feed command 5-6/24-2 3-2/24-1
from LSI chip #1.
DATA 1 | The 8 input data lines coming from P5-V,T,U,
DATA 8 the input device to the printer. X,S5M,W,
N/24-1
DATA STROBE A 0.5 usec (min.) pulse used to P5-Y/24-1 14-11/24-1
which prevents CLKTB1 until the rising
edge of ACK and prevent over-running
the buffer.
SIGNAL
NAME DESCRIPTION SQURCE DESTINATION
DCPRM Decoded Prime - Prime command from 5-8/24-2 9-31/24-2
LSI chip #1 to LSI chip #2 causes
prime condition.
DCWI-DCW5 Five full step data write pulses from ME9-24-2 ME20-24-4
LSI chip #2 to ROM character generator.
DCWO1-DCW04 Four half step data write lines to ME9-24-2 © ME30-24-4
half-step ROM for 9 x 7 dot matrix.
DLYLF Delay Line Feed - A 90 ms pulse 3-5/24-1 5-37/24-2
following any paper movement command.
Allows settle-out time for the form
feed mechanical parts.
DLYSTB Delay Strobe - A 450 us pulse used to 13-6/24-1 9-22/24-2
generate data write signals in LSI
chip #2 for the half step character
generators.
DSI-DS8 Buffered input data 1 to 8. ME8 & ME14/ ME17 & ME16/
24-1 24-3
DSCR Decoded Carriage Return + Command 5-12/24-2 9-33/24-2
from LSI chip #1 to LSI #2 to shift
data to memory output and backfill
shift register with zeroes.
DSTA Data Strobe A signal used to inform 14-10/24-1 5-18-24-2
LSI chip #1 that input data lines
should be strobed into memory.
EOPSW End of Print Switch - Terminates a P4-7/24-2 9-19/24-2
full line of print, 132 characters. 16-19/03-2
FAULT Printer fault signal to interface 5-9/24-2 P5-L/24-1
connector.
FFH Form Feed Hole - Vertical Format Unit. P4-D/24-2 5-29/24-2
INPUT PRIME A level from the interface connector P5-K/24-1 4-9/24-1
causing the printer electronics to be
printed.
GDSTB Gated Strobe - Gates strobe with ACK 5~17/24-2 E8/24-2