Xref: utzoo comp.sys.atari.st:12120 rec.music.synth:5033 Path: utzoo!yunexus!geac!syntron!jtsv16!uunet!ccicpg!peregrine!skywest!brenes From: brenes@skywest.UUCP (Erasmo Brenes) Newsgroups: comp.sys.atari.st,rec.music.synth Subject: Re: MIDI Networking Message-ID: <574@skywest.UUCP> Date: 26 Oct 88 17:30:14 GMT Article-I.D.: skywest.574 References: <3602@druhi.ATT.COM> <5080@saturn.ucsc.edu> <229@obie.UUCP> <4284@boulder.Colorado.EDU> Reply-To: brenes@skywest.UUCP (Erasmo Brenes) Organization: Sky Computers, Irvine, CA Lines: 21 In article <4284@boulder.Colorado.EDU> walkerb@tramp.Colorado.EDU (Brian Walker) writes: >In article <229@obie.UUCP> wes@obie.UUCP (Barnacle Wes) writes: >>If you reprogram these bits with 00, it tells the chip not to divide the >>clock, giving you a clock of 500 Khz, which is adequate for a simple, >>small network (like AppleTalk). > >Best to check that one out. Most USART chips require the clock division to >be set to at least 4 when using the asynchronous mode of the chip. You can >set the clock division to 0 only if you set the chip to synchronous mode. > The ACIA used by the Atari, the 6850B, can only be set to three divider modes, namely, by 1, 16, and 64. For MIDI, it is set to divide by 16 given its input clock of 500KHz. However, to set it to work in the divide by 1, ie. 500KHz, the received clock and data MUST be synchronized externally, for which the Atari ST has no provisions. So, it is not possible to run the MIDI port at 500KHz unless some additional hardware is added. Erasmo. P.S.: The hardware needed is trivial, but you would have to tinker with your soldering iron. :-)