1. How to make GM56flex (internal modem) work under Windows NT?
2. My 56K modem connects at 33.6K or less!
3. How to know the firmware version of GM56flex or GM56flex-E?
4. How to find out if the modem supports V.90 standard?
5. If I upgrade my K56flex to V.90, will I still be able to connect to K56flex modems at 56K speeds?
6. Why I often get modem disconnects?
7. Modem won't dial out under Windows 9x
8. What init strings enable/disable V.90?

How to make GM56flex (internal modem) work under Windows NT?

1. Adjust the jumper setting to non-pnp mode.
2. Avoid using com1 and com2, they are built-in com ports. Set the comports to either com3 or com4. Befor use any irq or i/o address, make sure they are not used by any other device. You can find this from Windows NT diagnostic program.
3. After setting up the modem and install the driver, check from the windows NT diagnostic program to make sure that IRQ number and IO number do not appear twice in the IRQ or IO list

My 56K modem connects at 33.6K or less!
If your Internet service provider doesn't support 56K, or one of you uses x2 and the other uses K56flex, you're out of luck. 56K requires that both ends have 56K modems, and they both have to use the same kind of 56K technology (x2 or K56flex).
Some Internet service providers have separate phone numbers for 56K. Make sure you're calling the right number.
If this is a Rockwell-based K56flex modem, issue an ATI3 command in a Hyper Terminal program. If the version is 1.0 something, you should try adding S202=32 to your init string.
Try disconnecting additional telephone devices (fax, phones, answering machines, etc.) from the phone line. This is a basic and useful step in modem troubleshooting.

How to know the firmware version of GM56flex or GM56flex-E?

1. Go to Windows control panel
2. Click modem and then diagnostic.
3. Please confirm that ATI6 is RCV56DPF L8570A Rev 45.0/45.0 or higher.
4. If it is RCV56DPF L8570A Rev 45.0/45.0 or RCV56DPF-PLL L8571A, you do not need to upgrade your firmware. This modems allready support V.90 standard.

How to find out if the modem supports V.90 standard?

GM56flex modem
Issue this command in a terminal program: AT+MS=?

The modem will respond like this:

(0,1,2,3,9,10,11,12,64,69)

The 12 represents support for V.90.

GM56PCI-L modem
Issue an ATI3 in a terminal program, or check the ATI3 response in the Windows 95 Modem control panel. If the ATI3 response shows firmware version 5 or higher, the modem supports V.90.

If I upgrade my K56flex to V.90, will I still be able to connect to K56flex modems at 56K speeds?
For GM56flex and GM56flex-E the answer is a definite "no". You'll be limited to a maximum 33.6 connect with the V.90 code loaded, and will have to go back to the K56flex code to get speeds greater than 33.6.

Please note: This does not apply to GM56flex (Version 2) that supports both K56flex and V.90. It has enough memory to support K56flex and V.90 simultaneuously. It only applies to K56flex modems that have been upgraded to V.90 with software, and is caused by limited memory in the modem.

Why I often get modem disconnects?
Generally, there will probably always be an occasional disconnect. After all, we are dealing with phone lines being pushed to their limits with V.32 and V.34 modems. Phone lines were designed for voice, not for data transmission. But if you're getting a lot more than the occasional disconnect, something is wrong and you should methodically follow the steps below.

1. Disconnections may be caused by momentary drops of DTR (Data Terminal Ready). By default, most modems respond to a drop of DTR by hanging up. With US Robotics and other modems, add S25=200 to your Modem String. This sets the duration, in hundredths of a second, that DTR must be dropped so that the modem doesn't interpret a random glitch as a DTR loss.
2. A similar possibility to the one above is that your modem could not distinguish between a line hit, or other disturbances that momentarily break the connection, from a true disconnect by the remote modem. Add S10=100 to the Modem String to set the duration, in tenths of a second, that the modem waits after loss of carrier before hanging up.
3. If you have call waiting and a call comes in while you are connected, your modem might interpret the second signal as a disconnect by the remote modem. Ask your phone company how to temporarily disable call waiting. Also, keep in mind that many ISP set their sites having an idle timeout. If there is no modem activity on your end for a certain length of time, say 15 minutes, you will be disconnected.
4. If you're disconnected shortly after logging in, you may be attempting simultaneous logins on the same account. Make sure no one is logged-in to your account such as a family member at home. If this isn't the case, try to add a Modem String to make your connection stronger. Check your modem's instruction manual for specific information about settings.

Modem won't dial out under Windows 9x
To make modem working properly, check the following steps:

1. Use Windows Hyper Terminal program and use standard windows modem driver to try. If you still have problem, it must be with either your system or the modem itself.
2. If step1 does not succeed, it is not necessary to proceed. Otherwise, you can try the following. Change the driver to the supplied modem driver and try. If it still does not work, change to other driver.
3. If the above two steps work, you need to install the modem using control panel's modem icon and click the diagnostic tab to see if it responds good. You also need to install the Microsoft dial-up adapter from the network icon of Control Panel.
4. If you are exploring the Internet or using Hyper Terminal to dial up BBS, you also need to setup the Dial-Up object correctly in the dialup networking icon.

What init strings enable/disable V.90?

GM56flex modem with V.90 firmware upgrade

GM56flex V2 modem (supports 56flex and V.90)

V.90 preferred (K56flex will still work)	+MS=12,1
V.90 only, K56flex and V.34 disabled	+MS=12,1,34667,56000
K56flex preferred (V.90 will still work)	+MS=56,1
K56flex only, V.90 and V.34 disabled	+MS=56,1,34000,56000
Disable V.90 and K56flex, use V.34 (28.8/33.6)	+MS=11,1

GM56PCI-L modem