RFOWLER@SIMTEL20.ARPA (06/26/84)
From: Ron Fowler <RFOWLER@SIMTEL20.ARPA> I'm involved in a project that involves the interconnection of several Micro's as a local area network under TurboDOS. I had planned to use one of the (very expensive, as it turns out) various new network controller chips, such as the WD2840 or COMM-9026. Recently, however I found out that the Zilog SIO is capable of 800KHz operation (in fact, I've heard that Televideo's TurboDOS implementation employs the SIO as the network controller). Since all of the computers I'm working with already have at least one SIO, I'd prefer to abandon the "fancy" net controller in favor of an SIO. Problem is, it seems that to get this kind of speed, you have to run in one of the synchronous modes (SDLC or Bisync). Does anyone know if this is true? Programming examples would be very helpful also (I don't suppose anyone has a TurboDOS driver already written for a high-speed SIO??? ) Another thing I'm not too sure of is the RS-422 interface itself (I'm considering a bus topology). When one station is transmitting on the RS-422, do all other transmitters have to be tri-stated? If so, what kind of turn-around is required for a station to become a transmitter? Any help will be much appreciated. --Ron Fowler -------