USRobotics V.34 user manual Summaries and Tables B-19

COURIER HIGH SPEED MODEMS

Register	Default	Function
S15	0	Bit-mapped register. To set the register,
		see the instructions for S13.
		Bit Value Result

01 Disable the modem's extra high-frequency equalization if it causes problems on shorter- link calls⎯HST-modems only

12 Disable online fallback

24 Disable 450 bps back channel⎯ HST only

38 Reset non-ARQ mode

Transmit buffer from 1.5K bytes to 128*

416 Disable MNP Level 4; retrans- mitting the larger Level 4 data blocks may be a problem if you expect a great number of errors during a call

532 Set backspace key to delete

664 Some earlier 2400 bps MNP modems, not made by U.S. Robotics or Microcom, were not fully compatible with the MNP protocol. If you have difficulty making a successful 2400 bps MNP connection with a remote MNP modem, it may be because of this incompati- bility. Set S15 to 64 and try again to make the connection.

7128 Custom applications only

*The default 1.5K byte non-ARQ buffer allows data transfer with X- and Ymodem-type file transfer protocols without using flow control.

The 128-byte option allows remote users with slower modems to stop data you're transmitting 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 doesn't exceed the size of their screen.

Summaries and Tables B-19