You have to turn off the analog comparitors on the 628 before you can use Port A
as a digital port.
I'm jealous that you could afford a 4004!  Slight drop in price, eh?
David

Larry Kayser wrote:

> Herbert:
>
> >         As long as one understands the implications of using a non
> interrupt method
> > you shouldn't have a problem with doing it without interrupts.
>
> Yes, I wrote my first hand assembler code over 29 years ago for a 4004.  I
> paid over $500 for the
> 4004 and flew to Texas to get it. It took several months of work to get the
> thing to print a single
> character "A" on an ancient now ASR MODEL 33 teletype machine.   I never had
> a real interrupt routine until I obtained an 8080 in 1974.  I also have
> Issue 1 of Byte Magazine, I go a long way back in this stuff hi.
>
> I still would really like to get in touch with someone who has actually done
> an INTERRUPTLESS
> USART implementation on a 16F628.
>
> I am also currently unable to get the 16F628 PORTA, h'05' but to come up in
> OUTPUT and make it go up and down (from a timer routine).  I have been able
> to ignore this for some time but I would like to see if anyone else can do
> it and how it was done.
>
> Merry Christmas to all on the List
>
> Larry
> VA3LK
>
> --
> http://www.piclist.com hint: The list server can filter out subtopics
> (like ads or off topics) for you. See http://www.piclist.com/#topics

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics