Re: Prototype card and info needed for project

[fhc <frankc@srv.net>]

Michael Spangler wrote:

> >
> >      As shown in the attached pic, you can interface to an 8255 using the
> > Device Select, R/W, RST, and a few address lines. D0-D7 on the 8255 go to the
> > D0-D7 Slot card lines.  (The addresses shown are for placement in Slot 2.)
> >
> >      The decoding uses the 8255's separate R and W lines and permits the IC
> > to be always selected (i.e. Chip Select is always active) in order to enhance
> > speed. Including A2 in the decoding makes it easier to add a second 8255.
> >
> >
> >
> > > Does anyone know a source of prototype cards for the Apple II?
> >
> >      Jameco may still sell Apple II prototype boards. However, the approach
> > suggested by Patrick is probably the one used by most experimenters.
> >
> >
>
> >      The Intel 8255 data sheet does a good job of explaining the different
> > possible configurations.
> >
> >
> >
> >
> > Rubywand
>
> A picture too! Now that's helpful. That answered the questions nicely.
>
> I found the 8255 specs at Jameco's web site. They do not have A2
> prototype cards any more, nor does Mouser, nor does digikey. The latter
> two do have commodore 64 cards though. So I'll have to get out the
> dremel and slice a PC board down.
>
> Thanks for the help. It was faster than I was expecting.
>
> Mike

I would just take a PC prototype board and cut off the extra contacts and if
needed cut the top down to fit in an Apple.  The spacing is the same for the
contacts.