Hal Communications CWR6850, Instruction Manual

Page: 38 / 64

CHAPTER 5 PAGE 38
5.4 Connection of a Different Keyboard
The CWR6850 is furnished with a reliable full-ASCII keyboard which should give long hours of sa-
tisfactory performance. However, it does connect to the CWR6850 using a standard parallel-ASCII
interface and another keyboard (or a computer) may be connected in its place. The following are
the specifications to be observed when connecting to the keyboard connector:
1. The keyboard must be capable of generating all standard ASCII codes and must generate posi-
tive 7-bit parallel output data and a 1 bit negative strobe pulse; set D8 to a logic "low".
2. The keyboard must operate from +5 VDC and require less than 250 mA DC.
3. The keyboard connector is a HIROSE 24 Pin Connector, HAL P/N 332-24000.
4. The pin connections are:
1 - Ground 7 - D6 13
2 - D1 8 - D7
3 - D2 9 - D8 to NOT USED
4 - D3 10 - NOT-STROBE
5 - D4 11 - NOT-ACK
6 - D5 12 - +5V 24
The NOT-ACK signal is not used in the CWR6850 on the present keyboard. When interfacing to a
computer, check the response from NOT-ACK before entering data.
5.5 Connection of an ASCII Printer
A serial ASCII data printer may be used with the CWR6850 by connection to the PRINTER connec-
tor. This output is a parallel, Centronics-compatible interface connection. The specifications of the
printer connection are:
Connector: HIROSE P-1612-BAC 12-pin plug (HAL 332-12000)
Wire: 12 Conductor cable (shielding recommended); 5 ft.
PIN USE PIN USE
1
2
3
4
5
6 GND
BUSY (NOT-RDY)
NOT-ACK
D8 (MSB)
D7
D6 7
8
9
10
11
12
HOT-STROBE
D1 (LSB)
D2
D3
D4
D5
Use a printer that includes a one-line buffer register and will do automatic line feed operations
when either the buffer is full or the ASCII line feed character is received (0A HEX). The output of
HOT-STROBE is a negative pulse of approximately 1.2 µsec. duration. The NOT-ACK input is not
read; data is output to the printer when BUSY (NOT-RDY) is in a "low" TTL state. Data output is
latched just before the next NOT-STROBE output pulse. The D8 output condition is set to a TTL
"low". The output is parallel 7-bit ASCII. The contents of the printer output FIFO register are dis-
played on the top two lines of page 2 of the display.
Data to the printer is turned on and off with the "CTRL-P" command. When the printer is active a
letter "P" will appear on the status line. The printer provides print-out of data AS IT IS RECEIVED.
When you use full duplex (normal amateur use), received data is printed as it is received. Since
the transmitted text is repeated or "echoed" in the receive buffer, it too is printed. If full duplex is
used, only receive data will be printed. Refer to the discussions of section 4.7 for more information
concerning full and half duplex operations. Since most printers use a line buffer, text will not be