Re: Apple //e RGB Card to CGA pinout?

["Bryan Parkoff" <nospam@nospam.com>]

"Knut Roll-Lund" <kr-lund@nogarbage.online.no> wrote in message 
news:-I2dnWRQnuGcrYPeRVnzvA@telenor.com...
> Bryan Parkoff wrote:
>>     There is no monitor FAQ.  How can I get information about the Apple 
>> //e RGB Card's DB-15 port pinout and CGA Monitor DB-9 port pinout?
>>     Do I need to find a adapter cable?  Or...Do I need to make adapter 
>> cable from my own scratch?
>
> I'm now waiting for my IIe RGB card so I'll have to figure that out. And I 
> have a CGA monitor and no AppleColor 100 RGB.
>
> CGA DB-9
> 1 Ground
> 2 Ground
> 3 Red
> 4 Green
> 5 Blue
> 6 Intensity
> 7 Reserved
> 8 Horizontal
> 9 Vertical
>
> according to "the PC programmer's sourcebook"
>
> IIe RGB DB-15
> 1 Ground
> 2 Green
> 3 Composite Sync
> 4 (not used)
> 5 Red
> 6 Ground
> 7 -5V
> 8 +12V
> 9 Blue
> 10 Intensity
> 11 (not used)
> 12 (not used)
> 13 Ground
> 14 (not used)
> 15 (not used)
>
> according to Marco Orlandi 
> http://www.exosystem.it/apple2/TheMarcorlandiModification_TTLRGB.pdf
> (it was not easy to find the pinning of that)
>
> I think; to use a CGA monitor I would need to extract the Horizontal and 
> Vertical sync signals before they are combined. This is probably possible 
> (analyzing the card when it comes) but...:
>
> Actually the trick that Marco explains in the document above is a rather 
> good one and I looked and I have a Mitsubishi HF2400 non multisync monitor 
> that can take R G B and combined sync so wow this is my solution I think. 
> Thank you Marco! When I got that monitor I thought that it would do 
> composite video too but no...
>
> His solution is very simple and I think it might even give a better image 
> if intensity would intensify only the active colors. In this simple 
> solution the intensity will also add to the inactive colors making a kind 
> of gray addition. Maybe the bright, active colors are so bright that the 
> effect on the inactive channels are not that noticeable. To do intensify 
> only the active colors would need analog switches etc.
>
> Knut
Knut,

    Thank you very much for the information.  I would use it to have 
feedback from you.  Please note that RGB will never work without NTSC design 
because RGB Card has to use NTSC's 4-bit color which it has 16 colors.  RGB 
Card has some transistors to detect NTSC's 4-bit color and convert it to 
4-bit R, 4-bit G, and 4-bit B like Apple IIgs' motherboard did.  I believe 
that RGB Card would depend on 14MHz to maniuplate video cycle while 
outputting to the RGB screen.
    I am trying to draw schematic from scratch by looking at RGB Card like 
Apple //c's video DB-15 port.

Bryan Parkoff