Reference Manual

PMAC 2 Software Reference
22 PMAC I-Variable Specifiation
Valid values of I3 and the modes they represent are:
0: PMAC does not acknowledge receipt of a valid command. It returns a <BELL>
character on receipt of an invalid command. Messages are sent without beginning or
terminating <LF> (line feed); simply as DATA <CR> (carriage return).
1: PMAC acknowledges receipt of a valid <CR>-terminated command with a <LF>; of an
invalid command with a <BELL> character. Messages are sent as <LF> DATA <CR>
[ <LF> DATA <CR> ... ] <LF>. (The final <LF> is the acknowledgment of the
host command; it does not get sent with a message initiated from a PMAC program [SEND
or CMD]). This setting is good for communicating with terminal display programs, such as
the PMAC Executive program.
2: PMAC acknowledges receipt of a valid <CR>-terminated command with an <ACK>; of
an invalid command with a <BELL> character. Messages are sent as DATA <CR> [
DATA <CR> ... ] <ACK>. (The final <ACK> is the acknowledgment of the host
command; it does not get sent with a message initiated from a PMAC program [SEND or
CMD]). This is probably the best setting for fast communications with a host program
without terminal display.
3: PMAC acknowledges receipt of a valid <CR>-terminated command with an <ACK>; of
an invalid command with a <BELL> character. Messages are sent as <LF> DATA <CR>
[ <LF> DATA <CR> ... ] <ACK>. (The final <ACK> is the acknowledgment of
the host command; it does not get sent with a message initiated from a PMAC program
[SEND or CMD]).
Note:
When I58=1 to enable DPRAM ASCII communications, I3 is
forced to 0 or 2 from 1 or 3, respectively.
Example
With I3=0:
#1J+<CR>......... ; Valid command not requiring data response
............................ ; No acknowledging character
UUU<CR> ........... ; Invalid command
<BELL>.............. ; PMAC reports error
P1..3<CR> ...... ; Valid command requiring data response
25<CR>50<CR>75<CR> ; PMAC responds with requested data
With I3=1:
#1J+<CR>......... ; Valid command not requiring data response
<LF> .................. ; Acknowledging character
UUU<CR> ........... ; Invalid command
<BELL>.............. ; PMAC reports error
P1..3<CR> ...... ; Valid command requiring data response
<LF>25<CR><LF>50<CR><LF>75<CR><LF>
............................ ; PMAC responds with requested data
With I3=2:
#1J+<CR>......... ; Valid command not requiring data response
<ACK>...... ; Acknowledging character
UUU<CR> ........... ; Invalid command
<BELL>.............. ; PMAC reports error
P1..3<CR> ...... ; Valid command requiring data response
25<CR>50<CR>75<CR><ACK>