Xref: utzoo comp.sys.tandy:2978 comp.sys.laptops:2066
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rutgers!zodiac!bittel
From: bittel@zodiac.rutgers.edu
Newsgroups: comp.sys.tandy,comp.sys.laptops
Subject: Re: Model 100: How to interface with system bus?
Message-ID: <607.27c3c879@zodiac.rutgers.edu>
Date: 21 Feb 91 13:17:45 GMT
References: <1991Feb10.203444.18109@daffy.cs.wisc.edu> <23244@well.sf.ca.us>
Organization: Rutgers University - Computing Services
Lines: 21

In article <23244@well.sf.ca.us>, tswift@well.sf.ca.us (Theodore John Swift) writes:
> Please help!  I'm trying to attach peripherals (A/D converters, analog
> multiplexers) to the system bus socket of a Model 100.  I have a copy of
> _Inside the Model 100_, which describes circuits for exclusively input
> or output buffers/latches, but nothing bidirectional.  All my attempts
> at hooking up a bidirectional buffer (using the read-not, write-not, and
> chip-select lines) either get no results or latch up the machine.
> Please reply if you've figured out how to do this, or if you'd like to
> chat about ideas.
> -- 

A great way to interface with the 8085 (model 100 microP) is using the 
Intel 8155 .. (remember to use the CMOS version 81C55)..  This chip
will interface directly to the bus and has three bidirectional ports!!
In fact, a look at the tech man. reveals that this chip is used within the
model 100 to drives the display, printer port, etc.. If you need more info
Email me.. 

Hope this helps..

-harry


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