I was able to use sudo to save a new default file. Minicom behaves exactly the same running from the live CD. Here is the diags from Windoze 7 - it seems ok to me 01-07-2013 21:46:16.925 - File: C:\Windows\system32\tapisrv.dll, Version 6.1.7601 01-07-2013 21:46:16.925 - File: C:\Windows\system32\unimdm.tsp, Version 6.1.7601 01-07-2013 21:46:16.925 - File: C:\Windows\system32\unimdmat.dll, Version 6.1.7601 01-07-2013 21:46:16.925 - File: C:\Windows\system32\uniplat.dll, Version 6.1.7600 01-07-2013 21:46:16.925 - File: C:\Windows\system32\drivers\modem.sys, Version 6.1.7600 01-07-2013 21:46:16.925 - File: C:\Windows\system32\modemui.dll, Version 6.1.7600 01-07-2013 21:46:16.925 - File: C:\Windows\system32\mdminst.dll, Version 6.1.7600 01-07-2013 21:46:16.925 - Modem type: U.S. Robotics V92 Fax PCI 01-07-2013 21:46:16.925 - Modem inf path: oem35.inf 01-07-2013 21:46:16.925 - Modem inf section: Modem_00D3 01-07-2013 21:46:16.925 - Matching hardware ID: pci\ven_12b9&dev_1008&subsys_00d312b9&rev_01 01-07-2013 21:46:16.956 - 115200,8,N,1, ctsfl=1, rtsctl=2 01-07-2013 21:46:16.956 - Initializing modem. 01-07-2013 21:46:16.972 - Send: AT 01-07-2013 21:46:16.972 - Recv: OK 01-07-2013 21:46:16.972 - Interpreted response: OK 01-07-2013 21:46:16.987 - Send: AT&F1E0Q0V1&C1&D2S0=0 01-07-2013 21:46:16.987 - Recv: OK 01-07-2013 21:46:16.987 - Interpreted response: OK 01-07-2013 21:46:17.003 - Send: ATS6=8 01-07-2013 21:46:17.003 - Recv: OK 01-07-2013 21:46:17.003 - Interpreted response: OK 01-07-2013 21:46:17.018 - Send: ATS7=60S19=0L1M1&M4&K1&H1&R2&I0B0X4 01-07-2013 21:46:17.018 - Recv: OK 01-07-2013 21:46:17.018 - Interpreted response: OK 01-07-2013 21:46:17.018 - Lowering DTR before closing port 01-07-2013 21:46:17.128 - Session Statistics: 01-07-2013 21:46:17.128 - Reads : 24 bytes 01-07-2013 21:46:17.128 - Writes: 68 bytes ATQ0V1E0 - OK AT+GMM - H.324 video-ready rev. 1.0 U.S. Robotics AT+FCLASS=? - 0,1,2.0 AT#CLS=? - COMMAND NOT SUPPORTED AT+GCI? - +GCI: ÿÿ AT+GCI=? - +GCI: (20,B5) ATI1 - 7AA0 ATI2 - OK ATI3 - U.S. Robotics 56K FAX INT V5.22.91 ATI4 - U.S. Robotics 56K FAX INT Settings... B0 E0 F1 L1 M1 Q0 V1 X4 Y0 BAUD=115200 PARITY=N WORDLEN=8 DIAL=TONE ON HOOK CID=0 &A3 &B1 &C1 &D2 &G0 &H1 &I0 &K1 &M4 &N0 &P1 &R2 &S0 &T5 &U0 &Y1 S00=000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=008 S07=060 S08=002 S09=006 S10=014 S11=070 S12=050 S13=000 S15=000 S16=000 S18=000 S19=000 S21=010 S22=017 S23=019 S25=005 S27=000 S28=008 S29=020 S30=000 S31=128 S32=002 S33=000 S34=000 S35=000 S36=014 S38=000 S39=000 S40=001 S41=000 S42=010 LAST DIALED #: ATI5 - U.S. Robotics 56K FAX INT NVRAM Settings... Template Y0 DIAL=TONE B0 E1 F1 L1 M1 Q0 V1 X4 BAUD=115200 PARITY=N WORDLEN=8 &A3 &B1 &C1 &D2 &G0 &H1 &I0 &K1 &M4 &N0 &P1 &R2 &S0 &T5 &U0 &Y1 S00=001 S02=043 S03=013 S04=010 S05=008 S06=004 S07=060 S08=002 S09=006 S10=014 S11=070 S12=050 S13=000 S15=000 S19=000 S21=010 S22=017 S23=019 S25=005 S27=000 S28=008 S29=020 S30=000 S31=128 S32=002 S33=000 S34=000 S35=000 S36=014 S38=000 S39=000 S40=001 S41=000 S42=010 Strike a key when ready . . . Template Y1 DIAL=TONE B0 E1 F1 L1 M1 Q0 V1 X4 BAUD=115200 PARITY=N WORDLEN=8 &A3 &B1 &C1 &D2 &G0 &H2 &I2 &K1 &M4 &N0 &P1 &R1 &S0 &T5 &U0 &Y1 S00=001 S02=043 S03=013 S04=010 S05=008 S06=004 S07=060 S08=002 S09=006 S10=014 S11=070 S12=050 S13=000 S15=000 S19=000 S21=010 S22=017 S23=019 S25=005 S27=000 S28=008 S29=020 S30=000 S31=128 S32=002 S33=000 S34=000 S35=000 S36=014 S38=000 S39=000 S40=001 S41=000 S42=010 STORED PHONE #0: #1: #2: #3: ATI6 - U.S. Robotics 56K FAX INT Link Diagnostics... Chars sent 0 Chars Received 0 Chars lost 0 Octets sent 0 Octets Received 0 Blocks sent 0 Blocks Received 0 Blocks resent 0 Retrains Requested 0 Retrains Granted 0 Line Reversals 0 Blers 0 Link Timeouts 0 Link Naks 0 Data Compression NONE Equalization Long Fallback Enabled Last Call 00:00:00 No Connection ATI7 - Configuration Profile... Product type US/Canada Internal Product ID: 00561002 Options V32bis,V.80,V.34+,V.90,V.92 Fax Options Class 1/Class 2.0 Line Options Caller ID, Distinctive Ring Clock Freq 92.0Mhz EPROM 256k RAM 32k FLASH date 7/28/2006 FLASH rev 5.22.91 DSP date 7/28/2006 DSP rev 5.22.91 ATQ0V1E0 - OK AT+GMM - H.324 video-ready rev. 1.0 U.S. Robotics AT+FCLASS=? - 0,1,2.0 AT#CLS=? - COMMAND NOT SUPPORTED AT+GCI? - +GCI: ÿÿ AT+GCI=? - +GCI: (20,B5) ATI1 - 7AA0 ATI2 - OK ATI3 - U.S. Robotics 56K FAX INT V5.22.91 ATI4 - U.S. Robotics 56K FAX INT Settings... B0 E0 F1 L1 M1 Q0 V1 X4 Y0 BAUD=115200 PARITY=N WORDLEN=8 DIAL=TONE ON HOOK CID=0 &A3 &B1 &C1 &D2 &G0 &H1 &I0 &K1 &M4 &N0 &P1 &R2 &S0 &T5 &U0 &Y1 S00=000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=008 S07=060 S08=002 S09=006 S10=014 S11=070 S12=050 S13=000 S15=000 S16=000 S18=000 S19=000 S21=010 S22=017 S23=019 S25=005 S27=000 S28=008 S29=020 S30=000 S31=128 S32=002 S33=000 S34=000 S35=000 S36=014 S38=000 S39=000 S40=001 S41=000 S42=010 LAST DIALED #: ATI5 - U.S. Robotics 56K FAX INT NVRAM Settings... Template Y0 DIAL=TONE B0 E1 F1 L1 M1 Q0 V1 X4 BAUD=115200 PARITY=N WORDLEN=8 &A3 &B1 &C1 &D2 &G0 &H1 &I0 &K1 &M4 &N0 &P1 &R2 &S0 &T5 &U0 &Y1 S00=001 S02=043 S03=013 S04=010 S05=008 S06=004 S07=060 S08=002 S09=006 S10=014 S11=070 S12=050 S13=000 S15=000 S19=000 S21=010 S22=017 S23=019 S25=005 S27=000 S28=008 S29=020 S30=000 S31=128 S32=002 S33=000 S34=000 S35=000 S36=014 S38=000 S39=000 S40=001 S41=000 S42=010 Strike a key when ready . . . Template Y1 DIAL=TONE B0 E1 F1 L1 M1 Q0 V1 X4 BAUD=115200 PARITY=N WORDLEN=8 &A3 &B1 &C1 &D2 &G0 &H2 &I2 &K1 &M4 &N0 &P1 &R1 &S0 &T5 &U0 &Y1 S00=001 S02=043 S03=013 S04=010 S05=008 S06=004 S07=060 S08=002 S09=006 S10=014 S11=070 S12=050 S13=000 S15=000 S19=000 S21=010 S22=017 S23=019 S25=005 S27=000 S28=008 S29=020 S30=000 S31=128 S32=002 S33=000 S34=000 S35=000 S36=014 S38=000 S39=000 S40=001 S41=000 S42=010 STORED PHONE #0: #1: #2: #3: ATI6 - U.S. Robotics 56K FAX INT Link Diagnostics... Chars sent 0 Chars Received 0 Chars lost 0 Octets sent 0 Octets Received 0 Blocks sent 0 Blocks Received 0 Blocks resent 0 Retrains Requested 0 Retrains Granted 0 Line Reversals 0 Blers 0 Link Timeouts 0 Link Naks 0 Data Compression NONE Equalization Long Fallback Enabled Last Call 00:00:00 No Connection ATI7 - Configuration Profile... Product type US/Canada Internal Product ID: 00561002 Options V32bis,V.80,V.34+,V.90,V.92 Fax Options Class 1/Class 2.0 Line Options Caller ID, Distinctive Ring Clock Freq 92.0Mhz EPROM 256k RAM 32k FLASH date 7/28/2006 FLASH rev 5.22.91 DSP date 7/28/2006 DSP rev 5.22.91 About the (A) question - I think it is of no consequence, especially keeping in mind that the modem worked ok at first. Also: "One drawback of the earlier 8250 UARTs and 16450 UARTs was that interrupts were generated for each byte received. This generated high rates of interrupts as transfer speeds increased. More critically, with only a 1-byte buffer there is a genuine risk that a received byte will be overwritten if interrupt service delays occur. To overcome these shortcomings, the 16550 series UARTs incorporated a 16-byte FIFO with a programmable interrupt trigger of 1, 4, 8, or 14 bytes. Unfortunately, the original 16550 had a bug that prevented this FIFO from being used. National Semiconductor later released the 16550A which corrected this issue. Not all manufacturers adopted this nomenclature, however, continuing to refer to the fixed chip as a 16550.[1] The 16550 also incorporates a transmit FIFO, though this feature is less critical as delays in interrupt service would only result in sub-optimum transmission speeds and not actual data loss." [1] ^ What are UART and How Do They Affect Performance? ( http://www.pccompci.com/uarts.html - good info here too) About "from your lspci output: "Kernel driver in use: serial"; this is not a module, correct?" - I don't know how to answer this. A bit more detail, please? About "from the setserial output: "Flags: spd_normal skip_test"; skip_test is usually set when there is a fake 16550 present; try without this flag, and see if the uart gets tested ok.", I also need more detail on exactly what to do. roger@roger-desktop:~$ sudo lspci -vvvk|grep "IRQ 17" [sudo] password for roger: Interrupt: pin B routed to IRQ 17 Interrupt: pin A routed to IRQ 17 roger@roger-desktop:~$ /etc/serial.conf - none present /etc/init.d/setserial... - "/etc/init.d/setserial" is present. Also, /etc/init.d/etc-setserial is present. Thanks!