Re: Z80 its refresh pin

[David Wilson <mcs6502@gmail.com>]

On Mar 29, 12:52 am, srk...@gmail.com wrote:

> > 2. SoftCard has to use a very special clocking scheme to be able to
> > access the Apple's memory transparently. It pulses twice during PH0 and
> > stays low during PH1. Well documented.
>
> I think i might have this bit ok. An image of the captured FPGA wave
> form shows it seems to look the part;
>
> http://users.tpg.com.au/srkh//PH0%2BPH1%2BPIN6.png

Unless my eyes deceive me, you have the double pulse during PH1 rather
than PH0.