Re: A new pseudo-disk for Apple 2.

["Alex Freed" <alexf@mirrow.com>]

"sicklittlemonkey" <Nick.Westgate@gmail.com> wrote in message
1153462554.229508.225530@p79g2000cwp.googlegroups.com">news:1153462554.229508.225530@p79g2000cwp.googlegroups.com...
>
> About swapping disk images - I'm not a hardware guy, but if you had one
> external pushbutton (think Wildcard), could you use DMA to stop the CPU
> and read the keyboard for the image number?

Yes, it can be done but requires a lot of logic (and wires on a prototype).
For DMA we have to drive all 16 address lines. Several TTL chips or
one more CPLD.

Thanks for the idea. I already thought of one button, but for NMI rather
than DMA.

-Alex.