TTL HEX LED driver chip

Dan Roganti ragooman at gmail.com
Tue Nov 2 12:09:25 CDT 2010


On Mon, Nov 1, 2010 at 8:00 PM, Chuck Guzis <cclist at sydex.com> wrote:
>
> On 1 Nov 2010 at 16:28, alan canning wrote:
>
> > I must admit I have not read thru all the posts so if somebody else
> > suggested this my apologies. Why not a one chip solution; use a 74S188
> > and program whatever you want the character set to be (i.e. hook or no
> > hook on 6s, etc. )?
>
> That's where we started.  Tony wanted to see what the minimum in
> combinatorial logic would be.  To date, I've not seen a solution that
> doesn't use decoders or demuxes, just AND OR and NOT elements.
>
> Anyone care to give that a crack and see what the optimal case is
> using SSI TTL--say, nothing more complex than a 7486?
>

I bet you enjoy changing the rules :)
Ok, but you didn't say >only< --- or no diodes ;)

>
> I'll eliminate some of the grunt work for folks and offer the
> following document, which contains all of the Karnaugh maps and a
> simple logic diagram.
>
> http://www.strivingafterwind.com/EE/EE112/ee112formal.pdf
>
> I'd probably start by using a 7404 and distribute the binary input
> and its complement... :)
>

oh gee, thanks :)

try this
http://tinyurl.com/2fjfnm5
excuse google for using a rather obtuse url for linking simple files

=Dan
--http://www.vintagecomputer.net/ragooman/



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