Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!usc!elroy.jpl.nasa.gov!lll-winken!ames!amdahl!key!beep!kris
From: kris@beep.UUCP (Port'naybl)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: MIDI
Message-ID: <109@beep.UUCP>
Date: 16 Nov 90 19:50:02 GMT
References: <4840.tnews@basso.actrix.co.nz> <3341@bruce.cs.monash.OZ.AU> <2464@cod.NOSC.MIL>
Distribution: comp
Organization: The Three Gadgeteers
Lines: 21

In article <2464@cod.NOSC.MIL>, bmarsh@cod.NOSC.MIL (William C. Marsh) writes:

 >However, the 8250's (and their offspring) have a built in baud rate generator,
 >which, unfortunatly, can not generate 31.25K 'baud'.  So, No, there isn't a
 >problem with the UARTS working faster (at least on faster machines) than
 >19.2K baud, but Yes, there is a problem generating 31.25K baud for MIDI.

     If I remember correctly, the 8250 baud rate generator is just a 16-bit
counter/divider.  I you feed 3MHz square wave into it, a divisor of exactly
96 will get you 31.25Kbits/sec.  Of course this is assuming your SIO clock
is 3MHz, otherwise the divisor would have to modified to fit.

     My apologies if I've stepped on any toes, but I wanted to mention this.
There is a UART, a 2681 I believe, that has its data rates limited to the
"standard" ones and won't do 31.25Kbits/sec.

-- 
						Port'naybl

key!beep!kris
woodowl!beep!kris

"Look what they've done to my program, look what they've done to my code;
 They stuck it all on this floppy disk, and I think they got it wrong, ma..."