Path: utzoo!attcan!uunet!lll-winken!ames!xanth!nic.MR.NET!umn-d-ub!uwvax!astroatc!nicmad!madnix!aaron
From: aaron@madnix.UUCP (Aaron Avery)
Newsgroups: comp.sys.amiga
Subject: Re: Multiple Serial Ports (Re: vt100 v2.9)
Message-ID: <372@madnix.UUCP>
Date: 10 Jan 89 08:44:48 GMT
References: <8812150227.AA09671@postgres.Berkeley.EDU> <14049@oberon.USC.EDU> <554@sunkisd.CS.Concordia.CA> <3241@sugar.uu.net>
Reply-To: aaron@madnix.UUCP (Aaron Avery)
Organization: ASDG Incorporated
Lines: 34

In article <3241@sugar.uu.net> karl@sugar.uu.net (Karl Lehenbauer) writes:
>To anyone who might be developing a multiport serial board, two things:
>
>1) Consider using the NEC 16550A's rather than 8250's or whatever, because
>the 16550's have a 16-byte typeahead buffer.  At high speeds, it is very

Thank you for the suggestion, but all of the multiport serial boards that
I'm aware of are well past the hardware design phase (I guess all but ours
would almost have to be, for me to know about them!).

The chip we use is the Zilog 8530 SCC. This is probably the chip most people
are planning to use. The 8530 can receive 3 full bytes before an overrun will
occur. Granted, 16 would be better, but it's not quite as bad as you perhaps
thought it was. Is the 16550A a superset of the 8530? The 8530 has some very
nice built-in features that a designer wouldn't want to give up. If it's pin
and software compatible with the 8530, maybe I'd like to look into it further.
Is it?

>2) Please support MIDI as well as RS-232.  Supporting MIDI requires only

Our device driver supports any baud rate from 110 through 38,400. So we fully
support MIDI in the software. In fact, our driver handles it better than the
serial.device does.

As for the hardware end, you'd have to adapt the port to MIDI just like you
would any other RS-232 port. Our little modules may be a little more hackable
than the Amiga motherboard, if you wanted to save a little money, but, of
course, that would void your warantee.

-- 
Aaron Avery, ASDG Inc.         "A mime is a terrible thing to waste."
                                 {decvax|att}!               -- Robin Williams
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