Standards
K56Flex: This is one of the first 56k protocols developed. It was developed before the ITU standard, so not everyone supported it. It was supported by most modem manufacturers except US Robotics, and USR clones. Some most ISP's also chose to support it.
X2: This is the other of the original standards, supported by US Robotics and some ISP's.
v.90: This is the new ITU standard. Most ISP's and modem manufactures are migrating to this. Mostly all KFlex and X2 modems are upgradable to v.90. (NOTE: Don't upgrade to v.90 until your ISP does. If your modem is v.90 and your ISP isn't then you will lose 56k access!)
Firmware
The firmware is the code that is stored in the modem's ROM. You can check your firmware by issuing the ATI3 command. If you have a KFlex modem, it will report something simular to: K_56_Flex_DSP v1.05. If your modem is X2, ATI3 will report OK. For v.90 modems, ATI3 will also report the firmware. Most modem firmwares are flash upgradable , which means that you can get a file from your modem manufacturer which will upgrade your firmware. It is advisable to upgrade your modem to the latest firmware.
Modem Command Strings
| K56Flex | |
|---|---|
| Rockwell Chipset | |
| Disable KFlex | +ms=11,0 |
| Enable KFlex, Disable v.90 | +ms=56,0 |
| Disable KFlex, Enable v.90 | +ms=12,0 |
| Lucent Chipset (LT WinModems) | |
| Enable v.90 | -v.90=1 |
| Disable v.90 | -v.90=0 |
| Enable K56Flex | S38=1 |
| Disable K56Flex | S38=0 |
| Lucent Chipset (Venus) | |
| K56Flex only, v.90 disabled | S109=0 |
| K56Flex and v.90 | S109=1 |
| v.90 only, K56Flex disabled | S109=2 |
| X2 | |
|---|---|
| Sportster | |
| Disable X2, enable v.90 | S32=34 |
| Enable X2, Disable v.90 | S32=66 |
| Disable X2 and v.90 | S32=98 |
| Enable X2 and v.90 | S32=2 |
| Courier | |
| Disable X2, enable v.90 | S58=1 |
| Enable X2, Disable v.90 | S58=32 |
| Disable X2 and v.90 | S58=33 |
| Enable X2 and v.90 | S58=0 |