Article 40434 of comp.sys.cbm: Xref: undergrad.math.uwaterloo.ca comp.sys.cbm:40434 Newsgroups: comp.sys.cbm Path: undergrad.math.uwaterloo.ca!csbruce From: csbruce@ccnga.uwaterloo.ca (Craig Bruce) Subject: Re: Desterm question Message-ID: Sender: news@undergrad.math.uwaterloo.ca (news spool owner) Nntp-Posting-Host: ccnga.uwaterloo.ca Organization: University of Waterloo, Canada (eh!) References: <3uueln$89f@news.cc.utah.edu> Date: Mon, 24 Jul 1995 15:18:26 GMT Perry Eidelbus wrote: >Not having a 128, nor even a copy of Desterm, I have a question >concerning it: does it have a hardware flow control (RTS/CTS) option? No, it only has software (XON/XOFF) flow control. >He claims that >Desterm defaults to RTS/CTS when the flow control is turned off. If >Desterm does not have RTS/CTS, as he claims, then that explains why his >best cps rates (with null-modem connection and downloading to the buffer) >are no more than 720 cps. His explanation is that "The >modem-to-motherboard speed is 4800 baud, period" on a 64, and 9600 on a >128; that the SwiftLink's enabling a 64/128 to go past the CIA chips' >speed is _hogwash_; that the many of you whom I have seen claiming all >these super cps rates are outright _liars_. What your friend is saying IS hogwash. The modem-to-motherboard speed is more like 8,181,816 bits/sec. The problem with Desterm's speed (or lack thereof) is Software Overhead, including the overhead of whatever downloading protocol is being used. If possible, you should try FX with your friend's setup, and you would see more than 960 cps throughput on a 128. >(BTW, I would figure that, once a few of you found out CMD's SwiftLink >cartridge didn't deliver on its promise of 38.4K bps, you'd not only be >complaining here but also getting together and filing a class-action >lawsuit against CMD for fraud.) The SwiftLink does indeed work at 38.4Kbps, because if it were more than 5% off from this figure, it wouldn't work at all. Your friend has much to learn about asynchronous serial communication. In fact, the SwiftLink's main chip is specified to work up to 125Kbps (given the right external serial clock rate). Keep on Hackin'! -Craig Bruce csbruce@ccnga.uwaterloo.ca "It's hardware that makes a machine fast. It's software that makes a fast machine slow."