HomeAbout ZoomTechnical SupportPartnersWhere To BuyProductsContact UsSearch  
ZOOM Products


version 1.7.3, dated 16 Mar 96

What is this document?

The purpose of this document is to answer as many end user questions as possible regarding the RPI(TM) technology, developed by Rockwell Semiconductor Systems.

Please be informed that Rockwell does not manufacture modems, and does not advertise modems to end users. We are providing this information as a general reference to end users. The information herein is subject to change at any time, and is not intended to substitute for the documentation that actually came with your modem product. Consequently, the information contained herein may not be pertinent or even accurate for your particular application.

Where can I find the latest version of this FAQ?

The latest version of this document will be available under the Technical Information section at http://www.conexant.com.

Table of Contents

What is RPI(TM)?

Rockwell Protocol Interface (RPI(TM)) is a technology that allows error correction and data compression (ECC) technologies to be performed in the PC host computer, rather than in the modem hardware, as has been done traditionally.

Technically speaking, RPI is an asynchronous HDLC (High Level Data Link Control) link that operates between a PC and a modem, allowing data compression and error correction to take place on the host PC. This allows RPI to operate using standard PC COM ports, or standard serial cards. The V.42bis bit stream presented to the remote modem from an RPI modem looks exactly like that which would come out of a traditional hardware implementation of V.42bis, fully synchronous and full duplex. MNP levels 2,3,4,5 are supported as well as V.42 LAP-M, and V.42bis.

To get ECC with RPI, as one would get using a hardware implementation of ECC, the PC comm application needs either a driver or a software package that supports RPI; the modem itself needs firmware that supports RPI.

Why did Rockwell introduce RPI technology?

RPI lowers the cost of traditional modem hardware by redistributing the Error Correction and Data Compression (ECC) processing load from the modem to the host computer, eliminating the need for external memories (RAM and EPROM) and allowing lower cost controllers to be used. This drive to lower the component cost was strongly driven by modem vendors desiring to offer the lowest possible end user price.

It also lowers the interrupt rate to the operating system (OS), as only precompressed data is sent on the COM port, unlike hardware ECC modems, which send uncompressed data over the serial port. If the data is compressible at a ratio of 2 to 1, which is very likely with ASCII text, then an RPI modem interrupts the OS approximately 50% less than a hardware ECC modem would.

How can I tell if the modem I am planning on buying has RPI?

Look for the any of the following phrases in the feature section of the modem carton:

  • "RPI(TM)"
  • "Software Error Correction and Data Compression"
  • "Error Correction and Data Compression software included"

What is the difference between RPI, RPI+, and WinRPI?

Is there more than one version of RPI?

There are two basic versions of RPI: the original RPI and RPI+.

The original RPI is found in Rockwell chipsets such as RC224ATL, RC224ATF, 1st generation (through firmware versions 1.620) RC144ATF and RC144ATi family.

RPI+ is found in most newly released code (from firmware version 1.628) of the RC144ATi and RC144ATF family as well as the recently announced RC144ACF, RC288ATF, and RC288ACF modems.

Note: The RC144ACF and RC288ACF can use either hardware or software ECC. These AC F-class modems power-up as a hardware based ECC modem but can also use RPI+ if WinRPI is enabled.

How can I tell which version of RPI I have?

The user can determine whether the modem is a RPI or RPI+ only modem by issuing an ATI3 to the modem.

A RPI modem will have the following string in its response:


A RPI+ modem will have the following response:


In either case, "V1.xxx" is the version number of the modem firmware.

In the 14.4 F-class modem chipsets (RC144ACF/RC144ATF), RPI+ is supported and the ATI3 output strings take the form:

ATF internal modem v2.200: V2.200-ACF/ATF_DP ROCKWELL RPI (TM) MODEM+01
ATF internal modem v2.400: V2.400-ATF_DP ROCKWELL RPI (TM) MODEM+01
ATF external modem v2.400: V2.400-ATF_DS ROCKWELL RPI (TM) MODEM+01


  • The RC144ACF supports both hardware and software ECC (WinRPI).
  • The RC144ATF only supports software ECC (WinRPI).
  • Some early versions of the ACF and ACi modems also reported RPI+ in the ATI3 even though they also contained hardware ECC. For example:
    • RC144ACF internal modem v2.200: V2.200-ACF/ATF_DP ROCKWELL RPI (TM) MODEM+01
    • RC144ACF internal modem v2.400: V2.400-ACF_DP ROCKWELL RPI (TM) MODEM+01
    • RC144ACF external modem v2.400: V2.400-ACF_DS ROCKWELL RPI (TM) MODEM+01
    • RC288ACi internal modem v1.400: V1.400-V34_DP ROCKWELL RPI (TM) MODEM+01
  • _DP indicates a "Desktop Parallel" modem which is an internal "card" modem.
  • _DS indicates a "Desktop Serial" modem which is an external "box" modem.

In early code revisions, both the RC144ATF and the RC144ACF include the RPI+ string in response to ATI3. In pre 2.400 code releases, the user cannot tell if the modem supports hardware ECC or not (unless the user makes a connection without WinRPI and sees if the resulting connection is ECC).
In 2.400 and future releases, the user can tell because an ACF modem will only include "ACF" in the ATI3 response and ATF will only include "ATF" in the ATI3 response.

What is the difference between RPI and RPI+?

RPI-based modems require PC comm apps that have an integrated RPI driver, called DAPI (for DOS) and WinDAPI (for Windows). To get ECC from an RPI modem, you need to use a DOS application that supports DAPI or a Windows application that supports WinDAPI. A list of these software packages is provided at the end of the FAQ. Using an RPI modem with an application that does not talk with these drivers means no ECC during online operation.

Later versions of RPI modems can use WinRPI as the RPI driver.

RPI+ modems will work with any Windows comm app to provide ECC as long as the correct SOFTWARE INDEPENDENT DRIVER (WinRPI) is loaded correctly. RPI+ under DOS still requires an application that integrates a RPI+ driver, which does limit the choice of DOS software that can support ECC.

What is WinRPI?

WinRPI is a Windows 3.1 communications driver shell which installs on the PC and performs ECC (error correction and data compression) on the host PC independent of the modem application software. WinRPI will provide this capability with both RPI and RPI+ modems.

What does WinRPI do for me?

Before WinRPI, RPI modem users wanting ECC could only work with software packages specifically supporting RPI modems. Now, WinRPI allows RPI and RPI+ modem users to work with all Windows 3.1 communications software packages.

What version of RPI firmware is needed to work with WinRPI?

WinRPI has been extensively tested with RPI version 1.620 and greater. Users have reported RPI version 1.510 works well with WinRPI. Some users have reported problems with WinRPI when using a modem with RPI version 1.403

How do I know if my modem needs an RPI driver?

Only modems that contain RPI or RPI+ need to be concerned about using an RPI driver. However, some modems contain both hardware and software (RPI+) error correction and data compression (ECC).

To determine if your modem is an RPI modem, before dialing or connecting, use the Windows terminal program and enter AT13 . RPI modems will indicate they are RPI capable by displaying a string of the form:
Rockwell RPI(TM) MODEM for RPI modems
Rockwell RPI(TM) MODEM+ for RPI+ modems

Although early revisions of modems based on the RC144ACF and RC288ACF chipset report RPI+ in the ATI3 response string, it is NOT necessary to use WinRPI, as the modem has built-in hardware ECC as well as RPI+.

The ATI3 output strings take the form:
ACF internal modem v2.200: V2.200-ACF/ATF_DP ROCKWELL RPI (TM) MODEM+01
ACF external modem v2.200: V2.200-ACF/ATF_DS ROCKWELL RPI (TM) MODEM+01
ACF internal modem v2.400: V2.400-ACF_DP ROCKWELL RPI (TM) MODEM+01
ACF external modem v2.400: V2.400-ACF_DS ROCKWELL RPI (TM) MODEM+01

In pre 2.400 code releases of the RC144Axx, the user cannot tell if the modem supports hardware ECC or not (unless the user makes a connection without WinRPI and sees if the resulting connection is ECC).
In 2.400 and future releases, the user can tell because ACF will only include "ACF" in the ATI3 response.

The following Table summarizes the situation:
Device Firmware Version Hardware ECC Software ECC Needs WinRPI?
RCx288ACF all Yes RPI+ -
RCx288ACi 1.400 and above Yes RPI+ -
RCx288ACi pre 1.400 Yes - -
RCx288ATF all - RPI+ Yes
RCx144ACi all Yes - -
RCx144ACF 2.400 and above Yes RPI+ -
RCx144ATF 2.400 and above - RPI+ Yes
RCx144AxF 2.200 ? RPI+ Probably
RCx144ATF 1.xxx - RPI Yes
RCx144ATi 1.xxx - RPI Yes
RCx224ATx chipsets use WinDAPI/DAPI in Windows/DOS program with builtin RPI support.

Can my modem have both hardware error correction (ECC) and RPI?

Yes. The recently released AC F-class chipsets have hardware error correction and data compression (ECC) built-in as well as having the RPI software interface. When transfering highly compressable text or files, using WinRPI can provide better throughput than hardware based ECC.

(Note: AT F-class modems contain the RPI software interface and do not have hardware ECC. )

The following chipsets/firmware versions support hardware ECC and RPI+:

  • RC288ACF - all versions
  • RC288ACi / RC288ACL - versions 1.400 and above (Released 10/95)
  • RC144ACF - all versions

For the sake of discussion, 3 terms can be used to describe the differences between some of the members in the F-class products:

  1. Hardware-only ECC - ECC performed inside of the modem
  2. Software-only ECC - ECC is performed on the host processor... for RPI modems, using WinRPI
  3. Dual-mode ECC - This is a modem that contains both hardware and software ECC mechanisms... but only 1 is operating at a time.

With recent product announcements, Rockwell now offers all 3 types of ECC modems. There are many factors (including cost, performance, flexibility, features, etc) which influence the design decisions of the modem manufacturers using the different chipset types. Not all of the reasons are directly evident/relevant to the end user.

On highly compressable data transfers (such as text files) the overall throughput/performance can be better with software ECC. The number of comm port interrupts (which have overhead) can be reduced and the host CPU may have more horsepower than the controller when doing the compression. The user can choose which method works better for their application(s). Se>

Transfer interrupted!

ing.html"> "WinRPI95 Throughput & Loading" White Paper for some performance comparison examples.

In some applications (such as the Macintosh) there is a limitation in the architecture which limits the DTE-DCE speed to 57600. Using RPI the user can achieve the (relative) 115200 and higher throughput (with a V.34 modem) because the data is compressed before it is sent to the modem and the DTE-DCE speed is around 30000. (At least one company has developed RPI drivers for their software/hardware modem package they sell for the Macintosh)

In general usage, it is likely that a user would only use one or the other ECC methods but the OEM can sell one modem that supports both methods which means that they can reduce the number of different products that they stock. (Economies of scale) Rockwell is just trying to make products flexible by supporting both methods.

What SOFTWARE works with RPI modems?

What Windows stand-alone communications programs work with WinRPI?]

Any communications program that uses the standard Windows COM interface, including:

  • Procomm Plus (PCPlus) 2.0
  • Windows Terminal (in Accessories)
  • QuickLink 1.4.3

What online connections service's programs work with WinRPI?

The following have been tested with WinRPI:

  • CompuServe - WinCIM ver 1.4
  • AOL Interface - ver AOL20 and AOL25
  • Prodigy - ver 1.1
  • NetCom - NetCruiser 1.0
Remember that WinRPI provides ECC to both RPI and RPI+ modems.

Does my existing RPI-capable windows communications software still work with WinRPI?

Yes it should, but you need to disable the built-in ECC routines (WinDAPI).

For example, in Procomm Plus 2.0 you can select either COM2 or RCOM2 (COM2 is an example COM port). After WinRPI is installed, select COM2 for WinRPI ECC instead of RCOM2 (which uses the older WinDAPI method). See next section.

If my old RPI program does not work after installing WinRPI, what can I do?

Use the WinRPI enhancer described below and in the WinRPI release notes for more details. Basically, this applet allows you to disable WinRPI and go back to the WinDAPI driver for ECC. Ironically, old RPI Windows RPI programs may be the only Windows programs that do not work well with WinRPI to get ECC. Of course, as described above, one only needs to disable WinRPI while using that old RPI program. WinRPI can be re-enabled afterwards using the WinRPI enhancer.

What Winsock programs work with WinRPI?

WinRPI has been tested with the following Winsock drivers:
  • Trumpet Winsock - version 2.1 Rev B (See A4. End user comments for an setup example)
  • SPRY driver used for WinSOCK access to Compuserve's internet access service.

I have a 3rd party Windows COMM driver... can I still use it with WinRPI?

Yes, you can still use it with WinRPI. WinRPI works with the standard Windows communications driver interface. See the WinRPI release notes on using CHGCOMM.EXE.

What versions of Windows does WinRPI work with?

WinRPI works with Windows 3.1 and Windows for Work Groups 3.1 and 3.11.
WinRPI95 works with Windows 95.
Click here for more information.

>Does WinRPI work with the "Windows version" of OS/2 ?

No support for OS/2 is planned at this time from Rockwell.

How does WinRPI work with the fax mode of my modem?

Facsimile transmission does not require V.42/V.42bis or MNP4/MNP5 for error correction and data compression. On modems supporting RPI+, WinRPI transparently passes data between the modem and the application software. On modems supporting the original RPI, WinRPI must be disabled using the Windows applet called "WinRPI Enhancer" (WRPIEN.EXE) before executing the fax application. See the WinRPI release notes for more information.

What can I do if I am not running Windows?

For modem ECC under DOS, you must be using one of the applications supporting RPI or RPI+. Apart from Windows and DOS, there is no planned support for any other OS.

RPI Performance

What limitations are there with WinRPI?

The PC must be running Windows software -- Windows 3.1, Windows for Workgroups 3.1.1, or Windows 95 in order for you to get transparent ECC with any Windows communications applications.

Does WinRPI slow down my PC?

WinRPI has no noticeable effect on a PC's performance (typically 2-4% performance decrease).

How powerful must my PC be to run WinRPI?

It is recommended to have a minimum of a 386DX-20 for good ECC performance under Windows with RPI or RPI+ modems. However, a 486-class is preferable if you plan to multitask with other applications while downloading data.

How do WinRPI modems compare in performance to hardware ECC modems?

WinRPI modems have the same data throughput performance as hardware ECC modems. Tests run on a 386DX-33 showed no appreciable throughput difference between a Rockwell hardware ECC modem and a Rockwell RPI modem. If you are transferring highly compressible data, and you want optimum performance, then a 486 class processor is recommended.

How much (Windows ) memory does WinRPI use?

Less than 100K bytes -- typically 60K bytes.

In what cases is it better to use WinDAPI instead of WinRPI?

If you are only using existing Windows RPI applications that came bundled with your modem, then stick with WinDAPI. If you want ECC with an Windows application that does not support RPI, then go with WinRPI.

WinDAPI must be used with RC224ATx and RC229ATx chipsets.

Getting, Installing, Configuring, Maintaining WinRPI

Where do I get WinRPI?

WinRPI is distributed in the following ways:
  • bundled with an RPI-based modem,
  • through your modem manufacturer (via tech support or BBS)
  • through the software vendor (via tech support or BBS)

Users on the Internet have reported that the following modem vendors have WinRPI available:
Vendor BBS # Notes
Best Data +1-818-773-9627
Cardinal +1-717-293-3074 for MVP144i and MVP144XF (not MVP144WIN)
Zoltrix +1-510-657-7413
Zoom +1-617-423-3733 via WWW

How do I install WinRPI?

If you have the default WinRPI package, run SETUP.EXE from the distribution disk and then change your COMM program's default initialization string to enable RPI using the +Hn command. See the WinRPI release notes for more information.

Note that the versions of SETUP.EXE through WinRPI 2.26 overwrite the Window's SYSTEM.INI file without warning or backup.

Some vendors (for example Zoom) have repackaged WinRPI to have a different installation method. Always check the accompanying documentation before trying to install.

AT+Hx - Enable/Disable RPI/RPI+ and sets DTE Speed when the modem is in RPI sync mode.

  • +H0 Disable RPI or RPI+.
  • +H1 Enable RPI and set DTE speed to 19200 bps.
  • +H2 Enable RPI and set DTE speed to 38400 bps.
  • +H3 Enable RPI and set DTE speed to 57600 bps.
  • +H9 Enable RPI+ and set DTE speed to 19200 bps.
  • +H10 Enable RPI+ and set DTE speed to 38400 bps.
  • +H11 Enable RPI+ and set DTE speed to 57600 bps.
Note: RPI+ can only be enabled in RPI+ modems, check ATI3.

Can WinRPI be installed on Windows 95?

WinRPI95 is now available for users of Windows 95 and RPI modems. win95rpi.exe

How do I install WinRPI if I already have RPI capable software installed?

Same as above.

How do I know if I already have WinRPI installed in my machine or if the modem I purchased has WinRPI already?

This answer applies to WinRPI. For WinRPI95, see How do I know if I already have WinRPI95 installed in my machine. Each modem manufacturer packages its software differently. Check the manual that comes with your modem to see if it has WinRPI. Also, when WinRPI is properly installed, you will see the following:
  • Comm.drv line in the SYSTEM.INI in the Window's directory contains the following line: COMM.DRV=WRPI.DRV
  • Window's directory contains the following file:
    • WRPI.INI (only necessary for original RPI modems)
  • Window's system directory contains the following files:
    • WRPI.DRV
    • WRPI.DLL

How do I know if I already have WinRPI95 installed in my machine or if the modem I purchased has WinRPI95 already?

Window's system directory contains the following files:
  • ROKV42.VXD
and they are referenced in the windows registry.
The system.ini file is not touched by WinRPI95 installation.

How do I configure WinRPI?

RPI+ modems require the application to issue the AT&C1&D2&K3+H11 command to it before connecting. You will probably want to set it as part of the default initialization string in your COMM program. RPI modems can be configured with the Windows applet called "WinRPI Enhancer" (WRPIEN.EXE). See the WinRPI release notes for more information.

How can I test to see if ECC is working?

Check your connect message the same as you would using a hardware ECC modem. On RPI+ modems, Error Correction and Compression messages can be enabled by setting ATS95=45. On original RPI modems, use the "Display Type" pane in the "WinRPI Enhancer" to enable protocol display (see WinRPI release notes). The compression messages are: "CLASS5" or "V.42bis". The error correction messages are "LAPM" or "ALT". Please refer to the S95 AT command in the modem manual for configuration details.

Many COMM applications expect certain types of display messages in order for their script to function properly. ATS95 or "Display Type" should be set appropriately."

Why doesn't my COMM application login script work?

Why does my COMM application "hang" during startup?

One possibility is that the response strings your modem and WinRPI are producing are different that what the application script writers expected. The response strings can be modified by changing the S registers settings in the "init string" for the application. (RPI-only modems would modify the responses with "WinRPI Enhancer"). Alternatively, the comm application script can be modified to accept the response strings produced by your modem/WinRPI configuration.

The WinRPI installation instructions indicate to set the S95 register to 45, but other values may work better for a specific comm application script. A little experimentation is often necessary. Start with S95 and perhaps S36 and S48. The Rockwell generic AT command manuals describe general S register settings.

Is there a BBS I can call that clearly reports what type of connection was negotiated?

No. Contact the BBS or online service which you have been calling and look for ECC connect messages listed in the above question.

Where do I go for help?

If additional assistance is needed, contact the modem manufacturer, the software vendor or Rockwell Web server (http://www.rss.rockwell.com/).

What modems have RPI?

The modems listed in the table below are reported to have RPI from comments received from users on the internet. This list is NOT exhaustive and is a bit old. Many of the manufacturers now have Web sites, they should be consulted for the latest official information.

Vendor Model Type/Notes
Aspen 14.4
Best Data 1442VF
Boca 1440AE external
Cal Com 1442I
Cambridge Telecom 1414HI
Cardinal MVP144I internal
MVP144iv2 ATI3 reports RPI, but has hardware ECC (ie, RC144ACF)
MVP144xv2 ATI3 reports RPI, but has hardware ECC (ie, RC144ACF)
Delrina Delrina 4 in 1
Dynalink 1414H
Global Village Gold II Macintosh
Logicode Quicktel 14.4LH
Maxtech (GVC) F(M)-114H internal
Prometheus 14.4i internal
Supra Express 144i internal
Not Express Plus
USR Sportster SI 14.4 internal (RC144ATF)
Sportster SI 14.4 external (RC144ATF)
Zoltrix FM 144 ATI internal
FM 144 ATE external
FM 144 ATF
Zoom 14.4 PC internal
14.4 EX external
Serial# xxxZA1ixxx or xxxZA2ixxx are plain RPI models
RPI+ models include serial# xxxZF1ixxx or xxxZF4ixxx

What controllerless / non-hardware ECC modems are NOT RPI?

The following are not RPI modems even though they do not have hardware ECC (amongst other things):
Vendor Model Type
Boca MV.34AI
Cardinal MVP144WIN
Multitech MT1932ZPXW

I'm still confused about RPI. Can you explain the different RPI terms and drivers again?

All users are in one of three situations today. Before going through this question, find out if you have RPI or RPI+, and whether or not you are you using WinRPI or not. Then, let's go through each one.
  1. RPI modem with DAPI (for DOS) or WinDAPI (for Windows).
    These users should obtain the WinRPI driver from their modem vendor. This will allow them to get ECC with any Windows application. DOS users still are required to use a supported RPI application shown in the list in Appendix 2.
  2. RPI modem with WinRPI (Windows).
    You can use any software application in Windows that talks to standard Windows COM port interface and get ECC.
  3. RPI+ modem with WinRPI (Windows)
    You can use any software application in Windows that talks to standard Windows COM port interface and get ECC. You also get the additional advantage of seamless fax transmission/reception capabilities. See the WinRPI release notes for further details.


A1. WinRPI release notes

WinRPI Version 2.26 Release Notes

WinRPI Ver 2.00 or later is a windows comm driver shell which allow the comm applications to run the ATi/ATF modems, which have the RPI or the RPI+ firmware, as error correction and data compression modems (similar to that of ACi/ACF modem) without modifications to the applications. This document describes:

  1. the WinRPI installation procedure
  2. the required initialization string
  3. the procedure for running WinRPI over other third party comm drivers
  4. notes on running WinRPI 2.XX on RPI and RPI+ modems
  5. the known bugs
  6. bug fixes
1) Installation:

Run the setup program from the distribution disk. The setup program will perform the following tasks:

A. Setup will copy the following three files from the disk to the Windows' system directory:

         WRPI.DRV (2.26)         The comm shell that routes windows'      
                                 comm calls                               

         WRPI.DLL (1.12)         The V42 engine.                          

         WRPICOM.DRV (1.05)      The comm driver that talks with the      

Setup will also copy the following file to the Windows' directory.

         WRPI.INI           The INI file is used to configure WinRPI to work  
                            with the regular RPI. This file is not required   
                            if the user is using RPI+ modem .                 

         WRPIEN.EXE         An applet (WinRPI Enhancer) which allows the      
                            user to modify the WinRPI.INI                     

Note, the time stamps on the WRPI.DRV, WRPI.DLL and WRPICOM.DRV correspond to the version number of the files.

B. Setup will prompt the user to see whether it should change comm.drv in the SYSTEM.INI to the following :


If the user choose not to have the above line changed by the setup then the user needs to change the line manually later.

C. Setup will created a program group and an icon for the WinRPI Enhancer (WRPIEN.)

2) Initialization string :

The following AT commands should be issued before calling or answering:

For RPI+ modem: AT&C1&D2&K3+H11

For RPI modem: AT&C1&D2&K3+H3S95=1

The user can determine whether the modem is a RPI or RPI+ modem by issuing an ATI3 to the modem.

A RPI modem will have the following string in its response: ROCKWELL RPI (TM) MODEM

A RPI + modem will have the following response: ROCKWELL RPI (TM) MODEM+

The following AT commands should be issued after a ATi 1.624 (or a later version) EPROM is plugged into the modem for the very first time. It sets the NVRAM to the current factory default.


3) Using other third party comm drivers:

WRPICOM.DRV is the comm driver that WRPI.DRV and WRPI.DLL use to interface with the UART. Currently, the WDAPICOM.DRV is the Rockwell RHSI Ver 1.05 with its file and modules names changed. The DOS utility chgcomm.exe provided with this release can convert any replacement comm driver into WRPICOM.DRV. The following is the procedure for converting:

1. Copy the comm driver to WRPICOM.DRV

2. Run the chgcomm.exe with the following two parameters: "WRPICOM.DRV" and "ORG_COM". Chgcomm changes the module name of a windows based EXE or DLL. The first parameter is the file name and the second parameter is the module name. Type the following line at DOS prompt:


3. Place WRPICOM.DRV in Windows directory, Windows' system directory or directories on the PATH.

4) Known Bugs:

The following is a list of known bugs that are currently being resolved:

No known bugs.

5) Notes on running WinRPI 2.XX on RPI or RPI+ modem:

RPI+ modem:

To run the RPI+ modem the users needs to issue the following string before calling or answering:


In the RPI+ mode, the user can select the protocol, compression and display type via AT commands (e.g. S36, S48, S95, etc.) See the AT command reference manual for additional information. WRPI.INI file, which is used with the regular RPI modem and described below, has no effect on the operation of the RPI+ modem.

Many COMM applications expect certain types of display messages in order for their script to function properly. ATS95 should be set appropriately."

When the WinRPI driver is installed, the users should disable the DAPI functionality in DAPI aware communication packages.

RPI modem :

To run RPI modem the user needs to issue the following string before calling or answering :


In the RPI mode, the user selects the protocol, compression and display types via WRPI.INI file.

To disable the WinRPI functionality, the users should set EnableWinRPI in the [Config] section to 0 in the WRPI.INI file as shown below:


If the WRPI.INI file or the EnableWinRPI entry does not exist, the WinRPI is by default disable when using a RPI modem.

Disabling the WinRPI functionality is required if the user wants to perform:

1. Fax or voice functionalities on a RPI modem with WinRPI driver installed. (Note, there are no such constrain if the user are using the RPI+ modems. )

2. Run DAPI aware communication applications.

Changes to the WRPI.INI file take effect the next time a user opens up a communications application. That is, the user should make the desired WRPI.INI change before opening up a comm package. Although the user can make changes to the WRPI.INI file while the comm package is opened, the user must exit and re-enter the comm package for the new setting to take effect.

The setup will place the WRPI.INI in the Windows' root directory. The setup will also install an applet called WinRPI Enhancer, which allow the users manipulate the WRPI.INI file. WinRPI Enhancer provides supplementary functionalities to RPI modems only. It has no effect on RPI+ modems.

A2. RPI Software Packages

RPI Software Info (as of 28 Feb 95)

Here is some information on which software versions support RPI. This is not an official statement/list... just tidbits collected off the Net. Please check with the vendors directly.

SOFTWARE            VER     DOS /   VENDOR                                
-------------       -----   ---     --------------------------------
WinRPI/WinRPI95              WIN     WWW:  http://www.rss.rockwell.com/
(driver supports most Windows communication programs)

Comit               1.24    WIN     TradeWind Software - 818-335-7007     
                    1.123   DOS                                           

Quicklink II        1.43    WIN     Smith Micro Software - 714-362-5800   
                    3.03    DOS                                           

Procomm Plus        2.00    WIN     DataStorm - 314-443-3282
                                    fax: 314-875-0595
                                    WWW: http://www.datastorm.com

Bit COM             3.03    WIN     Cheyenne Software - 510-490-2928      
                    6.04    DOS     bbs: 510-490-6637
                                    WWW: http://www.cheyenne.com

SuperVoice          ?       ?       Pacific Image - 818-457-8880          

WinComPro           latest  WIN     Delrina - 416-443-4332
                                    WWW:   http://www.delrina.com

Vodax               ?       ?       Tapmon - 714-249-9324                 

DataComm            ?       ?       Trio Information - 919-846-4990       

ExpressFax          ?       ?       WordPerfect - 801-846-4990            

Qmodem TD           4.6             Mustang - support@mustang.com         
                                    (QM46TD.zip - 2400 bps only) 
                                    WWW:   http://www.mustang.com

A3. Vendor FAQs

Cardinal FAQ

Help File for MVP144I/MVP144XF RPI Modems 6/6/95

"What Does RPI mean?"


  • PROBLEM #1 "When I connect to a BBS or service, the data on my screen displays nothing but garbage."
    ANSWER: Because an RPI modem does not have hardware error correction/data compression, (V42) it must be emulated by software that supports "Soft V42". Basically, without "Soft V42", you may experience problems connecting to high speed modems that are using error correction/data compression.
    If you are using the COMit software that came with your modem, go to the SETTINGS menu, select PORTS, and check on the option ENABLE SOFT V42.
    If you are not using COMit, you may want to check to see if the software you are using supports RPI or "Soft V42."
  • PROBLEM #2 "I can't upload any files to America Online or Compuserve."
    ANSWER: At the present time, some online services are having problems with RPI modems.
    Rockwell has created a program called WINRPI that corrects these problems. If you haven't received this program with your modem, you can download it from the Cardinal BBS at 717-293-3074. The file RPICIM.EXE can be found from the main menu or in the RPIMODEM library of files.
  • PROBLEM #3 "After installing the WINRPI program, I still can't get AOL or Compuserve to work properly."
    ANSWER: Make sure you have the correct modem selection in AOL or Compuserve software. Though choosing a compatible modem from the list may initialize the modem, it needs the +H3 command to activate the WINRPI program.
BAUD RATE = 57,600
For additional help, please contact us from one of the following.
Cardinal Tech Support line (717) 293-3124 8am-8pm EST
Cardinal Support BBS (717) 293-3074
FAX (717) 293-3043
EMAIL techs@cardtech.com
America Online type keyword CARDINAL


WWW server : http://www.zoomtel.com

Zoom recommends that Internet users site contact tech support

A4. End user comments

From: Christopher W. Hafey on Sat, Jul 15, 1995 10:43 AM
Subject: Zoom 14.4 PC RPI+ Modem performance report

Hiya Baudman,

     Well, I bought a Zoom 14.4 PC internal faxmodem, rpi+, in May,
1995.  I paid 50 dollars for it.
     Prior to that, I'd been contenting myself with a no-name 9600 bps
internal modem (no fax capability).
     The install disks for the Zoom 14.4 PC included software that was
adequate for any Windows-based telecommunications: WinRPI.
     The newly-installed Zoom 14.4 PC modem worked flawlessly, though I
noticed right away I could only use it with the included WinRPI driver,
and only under Windows---DOS-based modem apps were not supported.
[Note: DOS is supported through COMM apps with RPI bulitin.]
     I could not use it with GSZ.EXE, a favorite dos-based file transfer
protocol, nor FrontDoor..nor  any of my DOS-based telecomm software.
     I'm hoping to find a universal TSR that will work in DOS, similar to
how FOSSIL drivers are transparent in DOS, but enable certain things to
work correctly.. in this case, enable the soft v.42.
     Trumpet Winsock was one of the Windows-based programs I tried with
my new Zoom 14.4 PC RPI+ modem.  I had very good results, after tweaking
the Winsock for ideal internet settings.


     I have finally achieved, through experimentation, settings
for MTU, TCP RWIN, and TCP MSS that idealize this particular modem,
while running TCPMAN.EXE.


    MTU: 1500   TCP RWIN: 5840  TCP MSS: 1460.

    Baud Rate: 57,600 bps


  -Internal PPP
  -Hardware Handshake
  -Van Jacobson CSLIP compression

     These settings were changed under the "File, Setup" dialog for
TCPMAN.EXE (Trumpet Winsock).

     These settings have yielded, on a 386 dx 33 with 4 megs of RAM
running Windows For Workgroups 3.11, approximately 1700 cps file
transfer rates... in both sending from my PC to the Unix host, and
receiving (downloading) from that host, via ftp.  I've seen no
problems.. nor in fact could distinguish that I'd been doing so in a
soft v.42 environment (rpi+).

     Of course, my modem init for trumpet had to be correct:

# excerpted from login.cmd of TCPMAN.EXE program
$modemsetup = "&FQ0E1V1X4&C1&D2+H11S7=45S11=55s95=44F10M0"
# ATF10 locks to 14.4 kbps modem-to-modem
# ATF8  locks to 9600 bps modem-to-modem
# ATF5  locks to 2400 bps modem-to-modem

     There's probably some system.ini and win.ini settings which effect
this transfer rate.

System.INI includes:




     The only setting I'm aware of that was altered since installing the
WinRPI driver was the COM2FIFO setting, which was recommended by
Delrina's WinFax Lite software install.

     That's enough for now.  I'm hungry and it's past lunchtime!

     73, thanks for the web pages,

     de Christopher W. Hafey, WA1TNR since 1974

e-mail:		tingri@ntplx.net
www:		http://www.ntplx.net/~tingri/
voice:		(203) 826-6469
usnail:		43 LaSalle Court, #5
		New Britain, CT 06051-1074

A5. Vendor Contact Information

Aspen Computer Inc
5550 Main St, PO Box 346 
Buffalo, NY 14231-0346 
Phone: 716-626-0315   Fax: 716-626-1541 
(Aspen 14.4)
Best Data Products Inc
21800 Nordhoff 
Chatsworth, CA 91311 
Phone: 818-773-9600   Fax: 818-773-9619 
Email: bestdata@aol.com
(Best Data 1442VF, 1442FTQ, 1442FQ, 1442VTQ, 1442FTX)
Boca Research Inc
6413 Congress Ave 
Boca Raton, FL 33487 
Phone: 407-997-6227   Fax: 407-997-0918 
Email: support@boca.org
BBS: 407-241-1601 
(Boca 1440AE)
Cal Com Products
Placentia, CA 
Phone: 714-961-1888 
(CalCom 1442I)
Cardinal Technologies Inc
1827 Freedom Rd 
Lancaster, PA 17601 
Phone: 717-293-3000   Fax: 717-293-3055 
BBS: 717-293-3074 
AOL Forum Keyword: CARDINAL
Email: techs@cardtech.com
(Cardinal MVP144I, MVP144XF)
Cambridge Telecom Inc
Address Unknown
Phone: 408-980-0885   Fax: 408-980-0880 
(Cambridge 1414H)
(DataFax) Adtech Micro Systems 
43120 Christy St 
Freemont, CA 94538 
Phone: 510-659-0756   Fax: 510-659-9364 
(Datafax FX3 14.4)
DATASTORM Technologies
3212 Lemone Blvd.
Columbia, MO  65201
Tel: 314-443-3282      FAX: 314-875-0595
Delrina Corp
895 Don Mills, 500-2 Park Cntr 
Toronto, Ontario M3C 1W3 
Phone: 416-441-3676   Fax: 416-441-0774 
BBS Phone: 416-441-2752 
(Delrina 4 in 1)
(Dynalink)Computer Friends Inc 
14250 NW Science Park Dr 
Portland, OR 97229 
Phone: 503-626-2291   Fax: 503-643-5379 
Dynalink 1414H
Fountain Technologies Inc
50 Randolph Rd 
Somerset, NJ 08873 
Phone: 908-563-4800   Fax: 908-563-4999 
(Fountain Technologies 1414H)
Global Village Communications
685 E. Middlefield Rd, Bldg B 
Mountain View, CA 94043 
Phone: 415-390-8250   Fax: 415-390-8361 
BBS Phone: 415-390-8334 
Email: techsupport@globalvillage.com
(Global Village Gold II)
WWW:  http://www.maxcorp.com
FTP:  ftp://ftp.maxcorp.com/pub
Email: support@maxcorp.com
Compuserve : 71333,44
Prodigy:  Jump manufacturers BB
AOL: MaxTech
Phone (201) 586-8686     Fax   (201) 586-2264
Prometheus Products Inc
9524 SW Tualatin Sherwood Rd 
Tualatin, OR 97062 
Phone: 503-692-9600   Fax: 503-691-5197 
BBS Phone: 503-691-5199 
(Prometheus 14.4i)
Supra Corp
7101 Supra Dr SW 
Albany, OR 97321 
Phone: 503-967-2400   Fax: 503-967-2401 
BBS Phone: 503-967-2444 
Email: supratech@supra.com
Zoltrix Inc
437517 Seabreeze Dr 
Fremont, CA 94538 
Phone: 510-657-1188   Fax: 510-657-1280 
BBS Phone: 510-657-7413 
(Zoltrix FM 144 ATI, FM 144 ATE, FM 144 ATF)
Zoom Telephonics Inc
207 South St 
Boston, MA 02111 
Phone: 617-423-1072   Fax: 617-423-5536 
BBS Phone: 617-423-3733 
(Zoom 14.4 EX\PC Models 100, 110, 115, 150 and 160)
Sales -Toll Free  800-631-3116  9-6 Mon-Fri (Switchboard 8:30-6)
Fax- Sales        617-423-3923  24 hrs
Voice Main        617-423-1072  8:30-6
Repairs           617-423-2564  
Voice Tech Supp.  617-423-1076  8:30-11 Mon-Fri  9-5 Sat
Pay Tech Support  900-555-COMM  95 cents/min 8:30-6 M-F
Fax- Tech Support 617-423-5536  24 hrs
Faxback           617-423-4651  24 hrs
BBS               617-423-3733  24 hrs
AOL (keyword)     zoomt     
AOL Email         ZoomRep
Compuserve    GO  ZOOM                
Compuserve Email  76711,770
Internet Email    ZoomRep@aol.com           (Tech support)
Internet Email    76711.770@compuserve.com  (Tech support)
Other Tech Email  zoomrep3@aol.com    zoomtech@aol.com 
Internet Email    zoom@zoomtel.com   (General- will forward msgs, so slow)
Employment opportunities at Zoom               martyl@zoomtel.com
Investment information about Zoom              investor@zoomtel.com
Webmaster for comments regarding the Web site  webmaster@www.zoomtel.com
Zoom recommends that Internet users use the tech support form in their WWW site http://www.zoomtel.com/techsupport/index.html
©2008 Zoom    Home | About Zoom | Technical Support | Partners | Where to Buy | Products | Contact Us | Search