Xref: utzoo comp.sys.ibm.pc.misc:10569 comp.dcom.modems:10479 Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!bloom-picayune.mit.edu!athena.mit.edu!pshuang From: pshuang@athena.mit.edu (Ping-Shun Huang) Newsgroups: comp.sys.ibm.pc.misc,comp.dcom.modems Subject: Re: 4.77MHz PC sufficient for 19200 bps modem? Message-ID: Date: 19 Jun 91 23:47:44 GMT References: <1991Jun18.201125.6198@cs.cmu.edu> Sender: news@athena.mit.edu (News system) Organization: Massachusetts Institute of Technology Lines: 24 In-Reply-To: jch+@cs.cmu.edu's message of 18 Jun 91 20:11:25 GMT In article <1991Jun18.201125.6198@cs.cmu.edu> jch+@cs.cmu.edu (Jonathan Hardwick) writes: > We'd really like the extra speed if possible. Is the PC going to be > able to keep up with 19200 bps? How about 9600 bps? I think the original IBM-PC would be hard pressed to keep up with even 9,600 baud modems, much less a 19,200 connection. It may be just barely possible for this to work if you have (a) a communication program which doesn't impose too much overhead -- obviously comm programs which run under Windows are out, but character-based comm programs vary widely in the CPU time they "waste" in doing other processing; I would try {commo}, which is a very un-memory-intensive, un-CPU-intensive shareware comm program; (b) a serial port which knows how to buffer incoming characters (FIFO = First In, First Out). There's a serial port chip called 16xxxA, which can buffer a few characters. I don't know the details about the new Hayes smart serial ports, but they almost certainly also implement buffering, too. If you want to upgrade to better CPU, I would imagine a 12Mhz 80286 should do the job... probably better if you still consider (a) & (b). -- Above text where applicable is (c) Copyleft 1991, all rights deserved by: UNIX:/etc/ping instantiated (Ping Huang) [INTERNET: pshuang@athena.mit.edu]