Date   : Wed, 19 Apr 2006 18:25:11 +0200
From   : Anders Carlsson <anders.carlsson@...>
Subject: Re: Using an AKF30 with a Beeb

On Wed, 19 Apr 2006, Joel Rowbottom wrote:

> AKF30 [..] another "standard" I'd not heard of called PGA.
>
> Some rampant Googling forwarded me to this:
>  http://project64.c64.org/hw/1084s%20Monitor.txt

The 1084 monitors often are rebadged Philips 8xxx series. Some of those
have two RGB inputs; a 6-pin DIN for analog RGB and a 8-pin DIN for TTL.
I read that the AKF30 has a DB9 though, just like my 1084 monitor.

>> In TTL mode the picture was stable (not scrolling around) but red on black
>> and slowly fading away. The analog mode works much better on my monitor.

At least I know it probably isn't my monitor that is partially broken. :-)

It is probably due to feeding composite sync to a horizontal sync input,
but I tried to connect vertical sync to both 0V and the same csync input.
Neither worked well. Perhaps some circuit to split composite sync into
the two components would be useful for you guys.

The 1084 variant with a 8-pin DIN is specifically said to take either
composite or horizontal sync on the same pin, but apparently there is
a difference in the TTL RGB circuit on how the input is used.

-- 
Anders Carlsson