[sdiy] Re: bcd stuff

[Roy J. Tellason]

On Tuesday 03 August 2004 12:36 pm, WeAreAs1 at aol.com wrote:
> In a message dated 8/3/04 9:14:11 AM, ijfritz at earthlink.net writes:
>
> << At 03:16 AM 8/3/2004, Oakley Sound wrote:
> >Or a single 2716 EPROM programmed so that its eight outputs were
> >directly decoded by the address lines. I did that for the LED display
> >for my original Walshbank in 1986. But they probably don't make that
> >particular EPROM anymore, but I guess the principle still is OK.
>
> Just as an aside, I noticed that Ocean State Electronics still has the 2716
> listed. >>
>
> Just as another aside, it should be noted that pretty much any EPROM could
> be called into service for this task, even big ones like 27512's.  You're
> only going to use a very small amount (probably just sixteen) of the
> available addresses, so it will feel like overkill, but honestly -- even a
> 2708 would be overkill for this app.  I do like the idea, though.

I wouldn't go any earlier than the 2716,  as the 2708 needs more than one 
power supply to operate.  Though I have some vague recollection of hearing of 
a "2758" that was supposed to be a similar part using +5 only.  Never saw a 
data sheet on those,  though.

There are smaller proms out there,  but they use some sort of a different 
technolgy to program them and are mostly not erasable.  Seems to me like this 
would be a very useful part,  and I'm surprised that it's not more commonly 
used.

And why the heck does this list seem to default to a reply going to the 
individual who posted rather than to the list?  None of the rest of them I 
carry here do that...!