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From: RMS.G.HNIJ%MIT-OZ@MIT-MC.ARPA (John S. Labovitz)
Newsgroups: net.music
Subject: Re: rs232 midi interfaces
Message-ID: <8450@brl-tgr.ARPA>
Date: Fri, 22-Feb-85 01:41:12 EST
Article-I.D.: brl-tgr.8450
Posted: Fri Feb 22 01:41:12 1985
Date-Received: Tue, 26-Feb-85 20:36:33 EST
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> From: dave%rocksvax.uucp@BRL-TGR.ARPA
> Date: 20 Feb 85 16:35:00 GMT
>
> Typical asynchronous formats use 10 bauds to transmit 8 bits.  (1 start
> bit, 8 data, 1 stop bit)  Assuming that the thing is async, I believe
> it is, then, 30000/8= 3750 bytes/sec which would be sent at a rate of
> 37500 baud.  Most of the UART chips require a 16x clock to synchronize
> the data to its internal shift register so the chip requires a 600Khz
> clock.  Most old UARTS just make this.  I believe this was the reason
> they picked that rate and the crystal for the oscillator is an off the
> shelf value.
>
> Dave
> 
> arpa: Sewhuk.HENR@Xerox.ARPA
> uucp: {allegra,rochester,amd,sunybcs}!rocksvax!dave

actually, midi uses 31.25 kbps.  it comes out to a 500khz clock rate if
used at X16.

unfortunately, my cp/m box has a crystal the correct frequency to generate
all the `standard' baud rates (300, 1200, etc), but i can't get it to do
anything else.

i wish i'd kept my heath h89 -- it had an 8250, and could do any rate
(up to 56kpbs or so).

	@hnij@
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