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.
The latest version of this document will always be available under the Technical Information section on the Rockwell Semiconductor Systems Web Site, located at http://www.rss.rockwell.com.
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.
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.
Look for the any of the following phrases in the feature section of the modem carton:
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.
A RPI modem will have the following string in its response:
AFEP-V1.xxx-BP39 ROCKWELL RPI (TM) MODEM
A RPI+ modem will have the following response:
AFEP-V1.xxx-BP39 ROCKWELL RPI (TM) MODEM+
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
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.
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.
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?|
|RCx288ACi||1.400 and above||Yes||RPI+||-|
|RCx144ACF||2.400 and above||Yes||RPI+||-|
|RCx144ATF||2.400 and above||-||RPI+||Yes|
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+:
For the sake of discussion, 3 terms can be used to describe the differences between some of the members in the F-class products:
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). See the "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.
Any communications program that uses the standard Windows COM interface, including:
The following have been tested 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.
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.
WinDAPI must be used with RC224ATx and RC229ATx chipsets.
Users on the Internet have reported that the following modem vendors have WinRPI available:
|Best Data||+1-818-773-9627||via WWW|
|Cardinal||+1-717-293-3074||for MVP144i and MVP144XF (not MVP144WIN)|
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.
For Windows 95 users, make sure you download WinRPI95 instead of plain 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.
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."
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 and are available here.
|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|
|Global Village||Gold II||Macintosh|
|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|
|Serial# xxxZA1ixxx or xxxZA2ixxx are plain RPI models|
|RPI+ models include serial# xxxZF1ixxx or xxxZF4ixxx|
The following are not RPI modems even though they do not have hardware ECC (amongst other things):
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:
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 UART.
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 :
COMM.DRV = WRPI.DRV
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.
(Rockwell generic AT command manuals are available here.)
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:
chgcomm WRPICOM.DRV ORG_COM
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:
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.
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 WIN ------------- ----- --- -------------------------------- 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 - email@example.com (QM46TD.zip - 2400 bps only) WWW: http://www.mustang.com
Help File for MVP144I/MVP144XF RPI Modems 6/6/95
"What Does RPI mean?"
RPI stands for ROCKWELL PROTOCOL INTERFACE
Zoom recommends that Internet users use the tech support form in their WWW site http://www.zoomtel.com/tech-sup.html
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. TCPMAN.EXE Setup I have finally achieved, through experimentation, settings for MTU, TCP RWIN, and TCP MSS that idealize this particular modem, while running TCPMAN.EXE. Specified: MTU: 1500 TCP RWIN: 5840 TCP MSS: 1460. Baud Rate: 57,600 bps Enabled: -Internal PPP -Hardware Handshake -Van Jacobson CSLIP compression -DCD (RLSD) 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: [boot] shell=progman.exe comm.drv=wrpi.drv SCRNSAVE.EXE=(None) [boot.description] [386Enh] COM2FIFO=0 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: firstname.lastname@example.org www: http://www.ntplx.net/~tingri/ voice: (203) 826-6469 usnail: 43 LaSalle Court, #5 New Britain, CT 06051-1074
========================== 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: email@example.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: firstname.lastname@example.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: email@example.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 CANADA 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: firstname.lastname@example.org (Global Village Gold II) =============================== Maxtech/GVC WWW: http://www.maxcorp.com FTP: ftp://ftp.maxcorp.com/pub Email: email@example.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: firstname.lastname@example.org ========================== 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 800-666-6191 9-6 Mon-Fri (Switchboard 8:30-6) Sales -Toll Free 800-631-3116 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 email@example.com (Tech support) Other Tech Email firstname.lastname@example.org email@example.com Internet Email firstname.lastname@example.org (General- will forward msgs, so slow) Employment opportunities at Zoom email@example.com Investment information about Zoom firstname.lastname@example.org Webmaster for comments regarding the Web site email@example.comZoom recommends that Internet users use the tech support form in their WWW site http://www.zoomtel.com/tech-sup.html