Sound Card Packet  with AGWPE

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Most recent AGWPE version is:  2013.415  15 Apr 2013

Computer requirements
Packet Engine Pro

Configure AGWPE
Download and Install
Basic AGWPE Setup
2 Radio Setup
2 Card Setup

Sound Device Setup
Basic Device Settings
Rename Sound Device
Additional Settings
Using the Tuning Aid

Program Behavior

AGWPE Features
AGWPE on a Network
Baud Rates & Modes
Remote Control
TCP/IP Over Radio
Tips and Tricks
Traffic Parameters

Compatible Programs:
Setup Help

Radio Interface
Getting Started
Kits and Pre-assembled
USB SignaLink
Receive Audio Cable
Transmit Audio Cable
PTT (TX Control) Cable
2 Radio Modification

About Packet
Packet Overview
Exchange Modes
What To Do with Packet
Common Frequencies
Frame Headers
Further Reading

Running AGWPE on Older Computers

This page is intended for users that are trying to run AGWPE on pre-2005 computers and versions of Windows before XP. Most of the operating issues with AGWPE were resolved with post-2005 computers, so this page has little relevance to newer computers.

Note that it's impossible to give definite minimum requirements for running AGWPE. There are many variables that have an effect on AGWPE operations including processor speed and type, amount of  RAM, video card, sound card, sound card drivers, etc.

1. Older Operating Systems

AGWPE will run fine on Windows XP and, with a "work around", on Vista, Windows 7, 8.0 and 8.1.

For older operating systems (Win 98/ME), an older version of AGWPE,, may work although it obviously will not have any of improvements found in more recent versions of AGWPE. Some users have even been able to run this older version on NT 4.0 and Windows 95, although running AGWEPE on Win95 was a problem even for the program author.
For pre- Windows XP systems, please also see the Windows Update page for information about updating older Window systems. Also see the Enabling the TCP/IP Protocol in Windows page

AGWPE will not run in plain old DOS or Windows 3.1. It also will not run directly on a Mac or on Linux, but it will run under a Windows emulator. There is a product similar to AGWPE for Linux called LDSPED.

2. Processors/CPUs

George SV2AGW, the program author, wrote once that generally a Pentium II or newer processor should work without problems. Older, less capable processors may or may not work.

Here's a posting from one user successfully running AGWPE on a 486 66 MHz computer with Windows 95 and 28 MB of RAM:
"For 1200 baud AFSK digital signal processing (DSP) algorithms (i.e. packet) you do not need a lot of CPU power. If you're into real time video processing, yes, but in general a 486/66 is plenty for the DSP algorithms used in packet radio. Thomas Sailer who developed the algorithms considers a 486/66 as a minimum.

Also, keep in mind that even at a 44KHz sampling rate and at 16-bit resolution, you only need 88Kb to store 1 second of audio. The applications that we are talking about do not store huge amount of data, so a lot of RAM is not necessary for these applications. The only reason you might want to consider more RAM is to keep Windows running at a reasonable speed, leave more processing resources for user space algorithms, and prevent your packet applications from being swapped out to the swap file on the hard drive."

The real problem is how Windows handles resources, and how the drivers are being accessed by the applications. George mentions this on his web site. At this time I have AGWPE running on a small 486/66/28Mb/Win95 with no problem. I can surf the net and start other applications with no problem. WinAPRS and AGWPE keep humming."

And paraphrasing Stephen: "I run AGWPE very nicely on a mere classic Pentium 166 with MMX. If I put a P200 chip without MMX in the same machine, it won't run AGWPE reliably. Ham sound card programs are one of the few real-world applications where MMX actually does make a difference. In nearly every case, the presence or absence of MMX is the critical processor "horsepower" threshold that determines whether a sound card application will run or not. By the way, all Pentiums after the original "Pentium with MMX", in other words, all P-II, P-III, and P4 processors, incorporate the MMX instruction set as a matter of course."

3. Sound Cards

This site does not maintain a list of sound cards that "will not work with AGWPE", mostly because it would be hard to say definitely that the card was the problem, as opposed to the card's driver, or interface, or signal, or interference, or operator problem. Reports of  "receive" problems with some versions of on-board/integrated sound "cards" are fairly common.  Generally speaking, laptops do not have high quality sound "cards". Many have poor SNR ( signal-to-noise ratio) due to large amounts of background noise picked up from the hard drive, various buses, etc., and this makes reception and decoding of packet signal difficult. Transmitting is less of a problem.

George SV2AGW the program author has reported that some cards, such as the first versions of the SoundBlaster PCI128, have trouble with stereo channels, so you can only use them in AGWPE's Single Port sound card mode. He also found that the SoundBlaster SB16 inverts the channels during transmission -- if you send something to the left channel it will end up on the right channel.

Some older ISA cards are not Full duplex-capable and are troublesome.  Full Duplex means a card can playback while recording.   Imagine this situation: AGWPE wants to transmit, so it uses the sound card to listen to the frequency, hears that it is clear and, using the slottime/persist algorithm, picks a time to start the transmission. In full duplex mode, the transmission would start immediately. But if the card is not full duplex-capable, AGWPE has to tell the soundcard to stop recording (listening) and then wait for the soundcard to playback. This is important for packet, since relatively quick RX-to-TX switching times are critical. Cards that are not Full Duplex-capable will usually have problems maintaining a connection with another station and may just stop working with AGWPE after a few hours. For more information about FULL DUPLEX testing, visit the Problems with Packet Connections page

Some users have reported that cards which will work with other sound card programs, such as MixW or Digipan, but they will not work with AGWPE. George SV2AGW, the program author, says that one explanation may be that AGWPE uses the sound card in STEREO mode and at 22050 or 44100Khz sampling rates. Other programs use it only in MONO mode at a lower 11025 kHz sampling rate. The higher demands of AGWPE and packet may be too much for some cards/drivers/CPUs.

So, it's not uncommon to have a sound card problem, but most sound cards should be compatible with AGWPE.

4. Sound Card Problems?

If you experience problems that may be related to your sound card, here are some suggestions:

1. Temporarily plug in your speakers to the LINE IN jack, so you hear your packets.  If your computer/or driver is not fast enough, you will here interruptions or stuttering on the packet stream. In that case use only the left sound card channel in AGWPE. Also, set your VGA card accelerator a click below full level and adjust your soundcard sampling rate and quality until you find an optimum setting.

2. Make sure you have the most recent drivers of the card for your version of Windows. Those drivers should be on the card manufacturer's web site (as opposed to the computer manufacturer's site) or, for on-board sound "cards", contact the mother board manufacturer.

3. George SV2AGW also say that: "Another thing that you must have in mind is IRQ sharing. When your computer starts watch what IRQ assigns to Soundcard and if this IRQ is used by another device. If this is the case, adjust the IRQ from the BIOS and/or change the slot where your soundcard is located.

4. Other possible fixes reported by users are:

  • Upgrade to a newer version of Windows
  • For Win98SE and later try the VXD drivers for Win95/98OEM instead of the WDM drivers see footnote #1 below
  • Remove conflicting devices or drivers that access the sound card or its IRQ setting, e.g. the Philips WebCam audio driver was reported to be a problem. Use the BIOS or Windows to change the IRQ settings  or ...  
    plug the card into a different slot on the computer see footnote #2 below
  • Contact the sound card manufacturer directly and ask for a "raw" driver that might fix the problem. You can determine what soundcard chipset is being used in on-board, built-in sound "cards" with the Windows Control Panel Device Manager. You can then possibly go to the motherboard maker's  website -- not the computer maker's -- and download a driver for that particular chip and your version of Windows. see footnote #3 below

5. If the card still will not work, consider installing a second sound card. Note that Windows and AGWPE will support multiple sound cards, so you can continue using the original sound card for playing CDs, Windows' sounds, etc., while the second card can be used exclusively for AGWPE. (AGWPE will let you select which card to use.)
For desktops, you can purchase an inexpensive but compatible sound card for about $30 US. Or look for "used" cards at hamfests, computer stores, and in discarded computers.

There are also now USB sound cards, which may be a particularly attractive option for a notebook computer. One recommended device is the Griffin iMic for us$30-35.
Another option is the Tigertronics USB SignaLink which includes both a built in sound card and a VOX (voice activated) PTT circuit that negates the need to use a COM or LPT port on the computer for PTT purposes.

6. You can try using MixW's TNC emulation mode if your sound card will not work with AGWPE. If MixW works with the sound card, install the MixW virtual serial port emulation drivers mentioned on the MixW's TNC emulation mode page. Your application programs or AGWPE can then hook to one of the virtual serial ports and thus to MixW and its packet modems. So you could use MixW as the sound card modem and then use AGWPE's hosting services to share the MixW modem with multiple programs while it also manages any other "real" TNCs.

Remember, if your sound card won't work with AGWPE, it may not be AGWPE's fault. AGWPE uses Windows to do the actual hardware reading and writing in conjunction with the sound card's Windows device driver. In fact, it is the driver that has the hardware specific code in it, not Windows or AGWPE. With a well-written driver linking the sound card to Windows, a Windows program like AGWPE can operate under different versions of Windows and work with a wide range of sound cards without any sound card-specific program code. Since AGWPE doesn't link to the card directly, there is no way to add a "fix" in AGWPE for your card. AGWPE expects a sound card to have basic features and behaviors. Most cards do. Those that don't are the problem.  This is a bit of an oversimplification, but I hope you get the picture. (For more information from AGWPE's author, see this page:

Also remember that sound cards are subject to noise from the various other parts within your computer. This can create difficulties, particularly on receive, that can't be corrected.

Some programs to test your sound card are:


1  Chris has advice for installing VXD drivers instead of WDM drivers in Win98SE/WinME:
"I will not take credit for this. These fixes came from this group, the net and from a little experimenting.

It seems that many of us are using sound cards with Windows operating systems of 98SE and beyond. I see that WIN95 and the WIN98 doesn't have as much problems as the others systems. I'm not sure about XP, but I do work with the other operating systems.

I tried this on 3 computers and ran 98SE, ME, 2000 on these computers to check the drivers. If you have Win98SE, ME or 2000 and are having receiving problems.... check and see what drivers you are running for the sound card. You may need to run the VXD drivers, and not the WDM type (used by 98SE and above). Here are the steps to find out what driver you have:

1: On the desktop, right-click the "My Computer" and select "properties"

2: Click on the "Device Manager" tab.

3: Scroll down until you see "Audio (or Sound), video and game controllers" and click the "+" sign to expand it if it isn't expanded already.

4: Look to see if the audio driver (usually the first one) states WDM in its name or any of its associated files.
(a) If your files don't say anything, then click the the audio driver and select the "Properties" button.
(b) On the new pop-up window select the tab "Drivers"
(c) If this doesn't say WDM on anything (which is rare), then click the button "Driver File Details...".
(d) If you have any drivers in the WINDOWS\SYSTEM32\DRIVERS directory, then assume they are WDM.

If you do have WDM drivers, you might try downloading and using the WIN95 drivers.  These drivers are VXD type. You may have noticed that some of your drivers may say VXD, but that may not be the case as I found out.

You may be able to remove your existing drivers with an un-install program or my manually removing them. I recommend removing these files with the supplied un-install program if possible. Even with the uninstall program, you may have to remove the INF file in the WINDOWS\INF directory. You will need to know the INF file name.

Download the drivers for Windows 95 for your specific sound card. The reason I mention downloading is that most supplied sound card drivers on the disk/CD that came with the card are already out of date. Better to get the latest version. Remember WHERE you stored the driver. I recommend making a directory in your root drive called AUDIO and storing your driver file there on download. Then make sure you unzip, expand or whatever is required to that directory as well.

After you do this, it is recommended that you reboot the computer.

Once you do this, windows will boot up and state that it has found some new hardware or sound card. Tell windows WHERE you placed your driver, rather than having it search for the driver. If you let it search, it will load the WDM drivers and you will have to start all over again.

Hope this helps... Chris N0TTW"
2 Ramon reported "My video card is an AGP card located in the AGP slot. Now it seems, that often (because of the lack of interrupt), the AGP card shares resources with PCI Slot 1, which is the PCI slot next to the AGP slot in many systems. I read somewhere, that the first thing to try is moving any card from PCI slot 1.

So I moved my second audio card (for PSK31) from slot 1 to slot 6. I booted the computer, and it looks already a lot more stable after about 18 hours uptime. Note, that this was pure "trial and error", and that I didn't confirm that the IRQ overlap was a problem. If you have a rewriting problem, you could try this and see if it helps."

3  The Via website says: install onboard sound drivers provided by (your) motherboard manufacturer in preference to these (generic) audio drivers. This is because of the ID process in the Microsoft certification guidelines. Microsoft require a four part ID for PnP device drivers. If VIA has not received the appropriate ID from motherboard manufacturers, then the drivers from this package will use the generic ID instead. In some instances users may receive an error message or may even not be able to install the drivers. If this occurs, please contact your motherboard manufacturer for updated AC97 drivers.

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