->On 07-27-97  13:25 Rick Was discussing problem with Kenneth<-
 
 RC> On Jul 24 17:35, 1997, Kenneth Burgess of 1:2216/77 wrote:
 
 ->>On 07-22-97  14:57 Dennis Was discussing problem with Rick<-
 
 
 RC->> You can generally receive data with no flow control enabled (because 
 ->> the CPU is so much faster than the modem, the PC never has to tell the 
 ->> modem to "wait 
 
 KB>     Although most often true, not always true. Take for example these 
 KB>   system configurations. Although rare there are still some in use 
oday.
 KB>   System (1) is a bbs user, system (2) is the bbs being accessed.
 
 KB>   (1) -  2mhz CPU, 33.6k modem. Max buss at 19,200  
 KB>   (2) - 33mhz CPU, 33.6k modem. Max buss at max modem through put.
 
 KB>   Modem 1 & 2 can still negotiate a 33.6k link. However cpu #1 can not
 KB>   accept data from it's modem at that rate. If modems #1 and #2 are not
 KB>   BOTH configured for (Modem-Modem Xon/Xoff) flow control. There is a
 KB>   real possibility that buffer overruns WILL occur.
 
 RC> CPU 1 would possibly require flow control in that situation, but with
 RC> a USR  modem it will not connect at 33.6 with a 19.2 port rate.  The
 RC> receiving modem  would assert modem to modem flow control with the
 RC> sending modem, regardless of  the flow control setting used in the PC,
 RC> assuming an ARQ connection. 
 
    Yes you are correct. The max attainable link would be the max buss
  speed of the slower cpu, or the slower modem. Which ever is slowest.
  I should have looked my msg over, but was in a hurry. just didn't
  notice I had said a link of 33.6 (Wrong) instead of 19.2. :)
 
    And yes in that instance cpu #1 does require flow control. It must
  dedicate some of the processor time to screen & memory refresh. Which
  does not allow it enough time for a continous stream from the modem.
___ Blue Wave/DOS v2.30
 
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