W8SDZ@SIMTEL20.ARPA (Keith Petersen) (11/25/86)
The following message is relayed from my Remote CP/M system. --Keith Date: November 23, 1986 To: ALL US Robotics Courier Users From: Bob Clyne Subject: Courier drop back to 1200 bps when calling 2400 bps. There appears to be a problem with some Couriers which causes them to drop back to 1200 bps even though the answering end is at 2400 bps. I recently purchased a BYTCOM modem and in testing it I discovered that when I tried to call it at 2400 bps with a Courier modem that the Courier would usually drop back to 1200 bps even though the BYTCOM stayed at 2400 bps. After several telephone calls to both BYTCOM and US Robotics technical support I was finally informed by a US Robotics technician that the Courier sometimes mistakes the 2400 bps answer tones for 1200 bps answer tones. He would not say how widespread the problem might be but did give me a RMA number to send the Courier in and said they would check it and correct any problems. Let me re-emphasize that this problem only occured when the Courier was the "originate" modem, it worked correctly when it was the "answer" modem. It appears the problem only occurs with some other modems but occured with two different Couriers when calling the BYTCOM modem so it is apparently not an isolated case. The BYTCOM technician indicated he thought the problem occured with some but not all other makes of modems using the Rockwell chip set. For the record: there were no problems when using the BYTCOM modem with another brand of modem or with another BYTCOM modem. If you have experienced any similar problems, it might be adviseable to contact US Robotics and I (and probably others) would be interested in hearing about it. Perhaps we can determine how common or rare the problem is. Please send information to me at Royal Oak RCP/M (313-759-6569).