1. ES336_243001D.ZIP Driver
2. dsvd_rn.txt File Contents

dsvd_rn.txt Driver File Contents (ES336_243001D.ZIP)

Subject:	ES336D DSVD Driver Release Note V2.43.014B-d) 


DSVD allows simultaneous transmission of Data and Voice over the PSTN network and we could not find an Application specifically designed to accommodate our DSVD modem, PCPLUS for WINDOWS ver 2.11 and ESSDSVD.EXE utility can be used to test DSVD functionality.

Calls can be placed in two ways:

1-VOICE call first, then enable Data or
2-DATA call first, then enable Voice.

Detail Operation, refer to DSVD driver application notes.


Known bugs:

1- Is not advisable to use Hyperterminal with DSVD to transfer files using ASCII protocol because of slow transfer rates;

2- PCPLUS was not designed for full duplex file transfer. When modem does full duplex file transfer, if user keeps enabling/disabling Audio, eventually PCPLUS will falter. As far as we can tell this is
Application problem, not a modem bug. We do not see any problems when half duplex is used.

3- Modem needs a minimum amount of time to detect a user request. Once
   an off hook choice is made, for example, another off hook choice
   by the same user should be delayed by about 1 to 2 seconds to allow
   enough time to detect the change of state.

4- During retrain the Audio channel is disabled.

5- On rare occasions V.8bis negotiation might fail, but modems might still connect. In this case, a Data call, not a DSVD, takes place.

6- On rare occasions, about 2 in 1000, if Remote is in Command mode an
Local drops call, Remote might not disconnect.

10-In DOS-box no full duplex file transfer.

11-If both users repeatedly pick up TelSet within less than 1 second
interval from each other, one of the modems might keep Ringing until both sides hangup.

Notes:

1- The "Unistall ESS utility" might not completely remove all the
   folders that were created at installation time; if you encounter
   any installation problems and need to make sure all files have been
removed from your system, look for "ESS MODEM", "ESS DRVD" or similar clues.

2- Unistall will not delete ESSDSVD.EXE or ESSDSVD.INI from your
WINDOWS directory, or DELESS.BAT and UNINST.EXE from your VMM32 directory.

3- Buffer mode is not supported. LAPM connection is required for DSVD.

4- Two DSVD modems will not connect to each other in V.21 because no
error control and very low speed.