Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!boulder!paulc
From: paulc@boulder.Colorado.EDU (Paul Connally)
Newsgroups: sci.electronics
Subject: Alphanumeric LED driver
Message-ID: <9733@boulder.Colorado.EDU>
Date: 27 Jun 89 22:46:37 GMT
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Reply-To: paulc@boulder.Colorado.EDU (Paul Connally)
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Organization: University of Colorado, Boulder
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	Many thanks to all those who responded to my posting.
All the solutions I received were very enlightening but I have one
final question to this problem.

	I've decided to purchase a BCC-180 multitasking single board
computer from Circuit Cellar Ink.  The reason for this is that I have
some other processes that I'll definitely need it for (I know it would
be a waste just to program LED's with it!).  

	It has 48-bits of parallel I/O which will be plenty to multiplex
the LED segments with.  My question is, can I directly connect the anodes/cathodes , 74148 encoder, and the 7445 decoder to the parallel I/O lines.
The chips that the CPU (an HD64180) uses for these are 8255's.

	Or am I going bout this entirely wrong in connecting to the
parallel I/O?

	The CPU board also has an 8-bit BCC-bus, 2 asynch. serial ports, and
1 clocked serial port.

Paul Connally            	paulc@boulder.colorado.edu
University of Colorado  	High Voltage Electron Microscope Lab
MCDB  -  Box 347 		"A higher potential for 
Boulder, CO  80309		                 better penetration."