Re: Prototype card and info needed for project

[Michael Spangler <spangler@gorge.net>]

> 
>      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