Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!sun-barr!newstop!texsun!letni!rwsys!merch!cpe!hal6000!nemesis!uhclem
From: uhclem@nemesis.UUCP
Newsgroups: comp.sys.tandy
Subject: Re: <11712@techbook.com>
Message-ID: <-31053@nemesis>
Date: 18 Mar 91 11:42:09 GMT
References: <11712@techbook.com>
Lines: 20
Nf-ID: #R:techbook.com:11712:nemesis:-31053:000:981
Nf-From: nemesis.UUCP!uhclem    Mar 17 11:16:00 1991


<>
>Me too.  I want to make a MIDI interface.  I intend to model it on the design
>published in the MISOSYS Quarterly (V.i) for TRS-80's.  I need to know what I/O
>controller chip I can use to replace the Z80-SIO that that design calls for. 
>The 80C85 processor on the Tandy 102 that I have uses a multiplexed address and
>data bus.

You can use either a Zilog 8030 or a 8530 (I think it's the 8030, but my data
sheets are not available right now).  
The 8030 handles a multiplexed bus, while the other wants a de-multiplexed bus.

The 8030/8530 (also called Z80-SCC) are supersets of the Z80-SIO, in that
the first 8 registers are identical to those in the SIO.  The additional
registers allow you to fancier modes SDLC, NRZI,NRZ encoding, etc.


Frank Durda IV <uhclem@nemesis.lonestar.org>|"How do I know?  Well, I designed
...letni!rwsys!nemesis!uhclem	            | a multiport serial and a mini-net
...decvax!microsoft!trsvax!nemesis!uhclem   | board using the 8030/8530."