Robert Davis

Page last modified, URLs and HTML verified ... 13 February 2000
On this page:

- About your Amiga and 56k modems

- Specific information about the Sportster 56K

On other pages:

- To the first hints page

- To the second hints page

- Net security and the Amiga

- Return to my home page

Some important stuff:

All the information in these Hints files involve modifications to software and hardware which I have done myself, and which worked on my Amigas. If you have a problem, you are encouraged to send me e-mail describing the difficulty, but I will not be responsible for any of the changes or modifications you make to your own computer and its software.

Using 56k modems with your Amiga

This page is certainly going to change. I'll add links as I discover them and more information as I learn more about higher speed telephone modems and the Amiga. Please check back here now and then to see what I've added.
An aside .. you must understand that there are two data speeds we need to talk about. The first is the data rate between your computer and the modem, called the DTE or Data Terminal Equipment speed. The other is the data rate between your modem and the remote modem, called the DCE or Date Communication Equipment speed. For things to work correctly on modern systems, the DTE speed should be higher than the DTE speed.
My personal experience first:
I recently added a 3Com/USR Sportster 56k modem to my A3000. This particular unit is the X2 and v.90 compliant external modem, model 5686. It worked right out the box, with no changes to its configuration, without my even reading the nearly useless manual.
I just plugged it in and got a 48000 bps connection with x2 protocol to my local ISP.

Amiga requirements

Return to top of page. or goto remote system requirements.
Also, see specific information about the 3Com/USR Sportster.

To use a higher speed modem, your Amiga must be able to send and receive data to and from the modem at 57600 bps or faster, preferably 115,200 bps. Almost certainly, this will require a serial port other than the built in Amiga serial port which is not useful at higher speeds. (Remember that your Amiga serial port was designed back when a 2400 bps modem was state of the art.)

On my A3000, I use a GoldenGate II bus card and a PC-ISA type 16550 buffered UART card which works well at 115,200 bps. Those speeds are also useful even if your modem is a v.34 or v.34+ type, with line speeds of up to 33,600 bps.

There are many serial port options available for the different models of the Amiga. Older machines with a 68000 cpu and only a 7.15 Mhz system clock may have big problems with any high speed serial transfer, so you should plan on a CPU upgrade if you want faster Internet access.

Also, the serial port preferences settings on your Amiga do not apply when you use any modern communication program or TCP/IP program. Read that sentence again, ignore the preferences serial port settings.

Remote system requirements

Return to top of page.or goto Amiga requirements. Or check out some links to manufacturers.

The current state of the art for modems connected to telephone lines is like this:
An Internet Service Provider (ISP) can have a true digital connection to the telephone company switching equipment for a very high speed connection. Not all do have such a connection.
If the ISP does have the digital connection, then the ISP may choose to use a bank of modems which will send data at up to 53K (in the USA) or 56K (elsewhere). That particular type of modem can receive data at a different rate from which it sends data. Your upload data rate is limited to 31,200 bps. Note that data rate is not 33,600 bps.

Other modems, using the v.34+ standard, receive and send data at the same rate. Therefore, data transfers at 33,600 bps are possible with v.34+ modems at both ends of the connection. But your v.34+ modem will only connect to a so-called 56K modem at the remote modem's maximum data rate of 31,200 bps.

So here is a set of rules for modem (not just Amiga) users:
Your modem connection is always determined by the least capable of the two modems involved.
If you call BBSes, and want maximum speed on a telephone connection, get a v.34+ modem, which can connect as fast as 33,600 bps, but may not.
If you call an ISP, and want maximum speed on a telephone connection, get a modem compatible with the system used by the ISP. Your choices are usually v.34+, X2 (almost always 3Com/US Robotics), K56flex (Rockwell chipset, non-USR modems) or v.90 (the standard which should work, eventually, on all ISPs)

Here are some links to general information about high speed modems ...

Read about 3Com/US Robotics modems or read about the ITU v.90 specification.
The 'official' K56flex web site is maintained by Lucent Technologies the former Bell Labs company.

Be prepared for a sales pitch at all of those sites.

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Specific stuff about the 3Com/USR Sportster v.90 External Modem

The 3Com/USR Sportster v.90 external has a set of switches on the back of the modem. Here are the default settings as the modem comes from the factory. Look at the back of the modem, switch one adjacent to the telco connector.
Switch Functionon/upoff/down
2-Verbal codes-on-
3-Suppress codes
4-Echo commands-on-
5-Auto Answer
6-Carrier detect-on-
7-Use NVRAM-on-
8-Dumb modem
3Com/USR does not supply a printed instruction manual with the Sportster modem. A CD with lots of Windows and Macintosh stuff comes with the unit, certainly nothing about the Amiga is included. The user guides for several different 3Com/USR modems are on the cd.
is the path to the user guides, all stored in Portable Document File (.pdf) format.
On the aminet archive, you will find the xpdf program for viewing such images. Find it in the /gfx/show/ directory. As of August 1998, the filename on aminet is xpdf5e. There are versions for Amigas with 68020/030 cpus and for Amigas with 68040/060 cpus.

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Created on Amiga