gcw20877@uxa.cso.uiuc.edu (George Wang) (01/15/90)
I am having problems uploading files with Zmodem (with hardware CTS flow control ON) at high speeds... I have my COM port opened at 38,400 and the actual connection is at 14.4K... In this situation the manual says that one needs to use some kind of flow control... hardware preferred... Therefore, I *AM* using Hardware Flow control (even tried BOTH Hardware & Software) but both Zmodem and YModem-G fail with FLOW ERRORS.... I have a XT system with a multi-io that has a NS16550AN High Speed UART installed.... I have no problems DOWNLOADING files but when I UPLOAD files I get a FLOW error ever 4-5K and the transfer never goes through correctly... THe only way I can get UPLOADS to work is if I open the com port at 9600 and CONNECT at 9600 but this seriously HURTS the overall throughput!! Does anyone know how to fix this??? I would really like to get uploads going at an opened COM port of 38.4K for best results.. Could it be my XT system?? I heard that with the NS16550AN chip that even a XT system should be able to deliver speeds of 115,200 baud (IE, for NULL modem connections!) Thanks in advance! George -- George Wang University of Illinois gcw20877@uxa.cso.uiuc.edu
w8sdz@smoke.BRL.MIL (Keith Petersen) (01/15/90)
gcw20877@uxa.cso.uiuc.edu (George Wang) writes: >I am having problems uploading files with Zmodem (with hardware >CTS flow control ON) at high speeds... I have my COM port opened >at 38,400 and the actual connection is at 14.4K... In this >situation the manual says that one needs to use some kind >of flow control... hardware preferred... Therefore, I *AM* >using Hardware Flow control (even tried BOTH Hardware & Software) >but both Zmodem and YModem-G fail with FLOW ERRORS.... I use my HST modem with CTS/RTS flow control and DSZ's Zmodem protocol. Here are the settings I've found best for my application. Pay particular attention to &H1 and &R2, which are necessary for proper hardware flow control. Software flow control should not be used for file transfers in most applications where you are in direct phone contact with another HST modem (i.e., no packet switched networks inbetween). ati4 USRobotics Courier 9600 HST Settings.... C=1 E=1 F=1 M=3 Q=0 V=1 X=6 B=1 BAUD=19200 PARITY=N WORDLEN=8 DIAL=HUNT ON HOOK TIMER &A0 &B1 &G0 &H1 &I0 &K0 &M4 &N0 &P0 &R2 &S0 &Y1 S00=000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07=045 S08=002 S09=006 S10=007 S11=070 S12=050 S13=000 S14=000 S15=000 S16=000 S17=000 S18=000 S19=000 S20=000 S21=010 S22=017 S23=019 Keith -- Keith Petersen Maintainer of SIMTEL20's CP/M, MSDOS, & MISC archives [IP address 26.2.0.74] Internet: w8sdz@WSMR-SIMTEL20.Army.Mil, w8sdz@brl.arpa BITNET: w8sdz@NDSUVM1 Uucp: {ames,decwrl,harvard,rutgers,ucbvax,uunet}!wsmr-simtel20.army.mil!w8sdz