Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!sri-unix!ctnews!pyramid!oliveb!sun!clem!stoltz From: stoltz%clem@Sun.COM (Ben Stoltz) Newsgroups: comp.sys.mac Subject: Re: Programming for High Baud Rates Message-ID: <17343@sun.uucp> Date: Fri, 24-Apr-87 14:54:55 EDT Article-I.D.: sun.17343 Posted: Fri Apr 24 14:54:55 1987 Date-Received: Sun, 26-Apr-87 03:36:08 EDT References: <8254@clyde.ATT.COM> <441@wang.UUCP> Sender: news@sun.uucp Reply-To: stoltz@sun.UUCP (Ben Stoltz) Organization: Sun Microsystems, Mountain View Lines: 26 In article <441@wang.UUCP> lee@wang.UUCP (Lee Story x77155 ms 019 890) writes: >In article <8254@clyde.ATT.COM>, saf@moss.ATT.COM writes: >> >> The only problem is that again, you can't do this with the standard driver, >> you have to write your own. >> Steve Falco AT&T Bell Laboratories > >The rest of Steve's posting seems impeccably accurate, but I must take issue >with the comment that the standard driver won't support external clocking. >Indeed, you have to retrieve the SCC's control address from low memory and >poke the chip into "clock channel A from TRxC" and "divide-by-(16,32,64)", >but having done so, I've had no trouble running MIDI data capture, filtering, >rechannelizing and echoing utilities written entirely in Lightspeed Pascal >(even the poking for setup is done in Pascal). The ROM serial driver of >the Mac+ works fine and is remarkably efficient. >I can't guarantee that the 64K ROM driver or the RAM driver work, >but I suspect suspect that they do. > > Lee Story @ Wang Labs I've done the same on my 512e(quivalent). RAMSDOpen followed by "clock channel A from TRxC" and "divide-by-(16,32,64)" works very well as long as you don't need your driver to time stamp the data (which I don't). Ben Stoltz stoltz@sun.com