Re: 6526 serial register

From: Michał Pleban <lists_at_michau.name>
Date: Fri, 01 Nov 2019 14:11:18 +0100
Message-ID: <5DBC2EF6.5050707_at_michau.name>
Hello!

Nate Lawson wrote:

> Yes, I implemented this mode for full speed SRQ nibbling in the ZoomFloppy with a 1571. I clock data out at 2 MHz with the max speed (500 Kbit/sec) as well as in from the microcontroller.
> There’s a diagram with my oscilloscope showing this in this presentation: http://root.org/~nate/c64/xum1541/ZoomFloppy20100918.pdf
> It is stable though we’ve occasionally found a few 6526A CIAs that would get errors at this clock rate. The Amiga model seems to be more stable for this.

Thanks! I will try the 500 kHz - 2 MHz range then to see what happens.

> To reset the shift register, you can just reprogram the mode (I think). I know it works fine with no data persistence when I switch from input to output mode, for example.

Tha is also great info, many thanks!

Regards,
Michau.
Received on 2020-05-29 23:22:46

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