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Re: Apple II Video Generator

Subject: Re: Apple II Video Generator
From: Alex Freed <alex_news@alexfreed.com>
Date: Sat, 20 Oct 2012 16:07:21 -0700
Bytes: 1354
Newsgroups: comp.sys.apple2
Organization: Aioe.org NNTP Server
References: <6e405148-05d0-4ffc-94c6-20cbe931bffa@googlegroups.com> <a9428337-af9c-4118-ba99-40019e978f2e@googlegroups.com> <b4d40b5c-9b2e-436d-871b-047f098e8768@googlegroups.com>
User-agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20120907 Thunderbird/15.0.1

Apple 2 doesn't have any DAC circuitry. It can only output 3 levels onthe video out: sync, black and white. The gray low res color is coded as$5 or $A - either way it's a square wave with an average level of 1/2between black and white. 0 is black, $F is white. All others areinterpreted as colors because there is a component in the signal thatlooks like a 3.58 MHz color carrier to the NTSC TV.


-Alex.

References:
- Apple II Video Generator
  - From: Immortal Nephi <Immortal_Nephi@hotmail.com>
- Re: Apple II Video Generator
  - From: Kevin <kevin@hackaday.com>
- Re: Apple II Video Generator
  - From: Immortal Nephi <Immortal_Nephi@hotmail.com>

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