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Re: Apple Graphics Tablet



Vladimir Ivanov wrote:

Hey Alex,

On Mon, 18 Jun 2012, Alex Freed wrote:

On 6/18/2012 11:10 PM, Vladimir Ivanov wrote:


Q3 is more like strobe than clock - both composite and non-50% duty
cycle. The creative abuse in Disk II interface won't work for all
scenarios.


Actually a 50% duty is not often needed for a clock - the circuits like flip-flops and counters only care about one edge.


True. I was merely pointing out that there is no regular 2 MHz clock in the Apple II.

I don't know the MockingBoard, Phasor and the likes, but if they feed re-generated 2 MHz to the internal sound oscillators (i.e. don't have on-board master clock) that explains why Q3 wasn't suitable.

The Mockingboards use a slightly delayed (RC delay) Phase 0 clock
(1 MHz).

-michael

NadaNet 3.1 for Apple II parallel computing!
Home page:  http://home.comcast.net/~mjmahon/

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