AEA PAKRATT PK-232, Technical Reference Manual

Page: 32 / 101

PK-232 TECHNICAL MANUAL CHAPTER 4 – HOST MODE AND SPECIAL APPLICATIONS
PK232TM Rev. A 5/87 4-15 Page 32
4.9.3 I/O Command
Use the I/O command without arguments to read an I/O location and with one argument
0-FF to write to an I/O location. The value in ADDRESS is not incremented after using the
I/O command.
Load ADDRESS with these values for easy access:
$BF0D Parallel port A
$BF0E Parallel port B
$BF0F Parallel port C
$7C08 Terminal data
$7E08 HDLC data
$7E00 HDLC RR0
HDLC RR0 is the status register of the radio interface. The following information can be
read from RR00:
bit 7 Break/Abort
bit 6 TX Underrun/End of message
bit 5 CTS (Read data)
bit 4 Sync/Hunt
bit 3 DCD
bit 2 Transmit buffer empty
bit 1 Zero count
bit 0 Receive character available
4.10 Converse and Transparent Modes
In Host mode, data is sent using the setting of CONMODE.
o Do not send the CONVERSE or TRANS commands to the PK-232.
o If CONMODE is CONV, the parameters 8BITCONV, ALFPACK, ALFDISP, LCOK and
ESCAPE are active.
o If CONMODE is TRANS, all characters are passed without modification.
These are the only differences between CONV and TRANS while in Host mode.
4.11 MHEARD Command in Host mode
The MH command has been altered in Host mode because the verbose mode MHEARD re-
sponse is potentially too long for the limited Host mode response buffer.
The MHEARD response is divided into lines numbered 0-17. The MHEARD list must be polled
on a line-by-line basis.
o Use the host command MH0 (SOH $4F M H $30 ETB), then MH1, MH2, etc. until
you get an empty response (SOH $4F M H $00 ETB), or until you reach the last
(MH17) line.
CAUTION: If the PK-232 receives a Packet frame while the computer is polling the mid-
dle of the MHEARD list, the list entries may be garbled. One possible solution
would be to temporarily set HBAUD to 110 to disable Packet, poll the 18
MHEARD lines, then set HBAUD back to 1200.