3Com 1.024.1644-00 - Manual (Page 73)

Technical Reference
67
Register Default Function
S13 (Continued)
* The 1.5K-byte non-ARQ buffer allows data transfer with Xmodem- and
Ymodem-type file transfer protocols without using flow control.
The 128-byte option lets remote users with slower modems keep data you
are sending from scrolling off their screens. When remote users send your
computer an XOFF (Ctrl-S) and you stop transmitting, the data in transit
from your modem’s buffer does not exceed the size of their screen.
This is also very helpful in situations when a remote modem/printer
application is losing characters.
S14 0 Reserved
S15 0 Bit-mapped register setup. To set the register,
see instructions for S13.
Bit Value Result
0 1 Disable ARQ/MNP for V.22.
1 2 Disable ARQ/MNP for V.22bis.
2 4 Disable ARQ/MNP
V.32/V.32bis/V.32terbo.
3 8 Disable MNP handshake.
4 16 Disable MNP level 4.
5 32 Disable MNP level 3.
6 64 MNP incompatibility.
7 128 Disable V.42 operation.
To disable V.42 detect phase, select the total of the
values for bits 3 and 7 (in other words S15 = 136 [the sum
of values 8 and 128])
S16 0 Reserved
S17 0 Reserved
S18 0 Test timer for &T loopback testing. Sets the time in
seconds of testing before the modem automatically times
out and terminates the test. When set to 0, the timer is
disabled. Valid range is 1-255.