Found a scan doubler ( who would like one ) ?

[hardlink]

-D- wrote:
 I ran the internal DCE unit for years and thought it was great, though now I'm wondering if it skewed my impression of AGA capabilities (like HAM8 photo viewing).

Bummer I sold it, as now would be a great time to make some comparisons... especially if the unit is in fact 16-bit.

You are on this side of the pond and you let an internal SD/FF get away???

The only time I saw one over here was at the EyeTech booth at the 2001 Gateway show. Alan Redhouse did not want to schlepp remaining stock back to the UK, so he offered either the internal or external for about US$60. I couldn't afford both, so I picked the external because it works on any Amiga, and I've been regretting the choice ever since.

That external SD/FF, and probably this new one too, adds a lot of noticeable noise to the image because of the extra Analog->Digital conversion. Still looking for an internal unit for my A1200, after all these years.

[hardlink]

-D- wrote:
One positive thing to consider though, the internal unit runs really hot, as do the custom chips that are covered up by it. Might have an effect on longevity, which isn't an issue with your external version. Also, I found it to be kind of a PITA in a desktop case. (Between the IDE-Fix "Express" and the SD, 3 custom chips were covered up, LOL.)

Yes, those are very good points, especially about the DCE internal. Looks like the Micronik Scandy 1200 was a different design approach, with 2 small bare/passive chip 'snap-ons' and only memory and 2 big custom(?) chips on the main PCB snap-on:

http://www.amiga-hardware.com/showhardware.cgi?HARDID=373

I wonder if a design like this could be resurrected; maybe 3  passive ventilated snap-ons and a PCB that could be placed out of the way. Seems like it should be even simpler than an external unit if you can grab the digital RGB data, saving 3 A/D converters, and the image quality would be MUCH better.

[hardlink]

alexh wrote:
For the best picture quality and colour representation the AL250a could be used on it's own directly attached to the Lisa/Denise chips without an AL875 ADC, but it would be and "Amiga only" solution. You'd need a different one for ECS and AGA Amiga's. It wouldnt be worth it. And it would still be 16-bit ;-)

Now your'e talking! I'm not so sure about needing one for ECS, the A3000 has one built in, and the A500 and A2000 can use the  old ICS Flicker Free Video 2, which seem a lot more plentiful than AGA internal doublers (I even have 2 of the ICS boards). And screw the A600

So for 16-bit quality, you think the AL250a would work? Does it need external RAM?

[hardlink]

alexh wrote:

hardlink wrote:
So for 16-bit quality, you think the AL250a would work? Does it need external RAM?

Yes, no.

Does anyone here have or can they get the full datasheet for the AL250a? Only the 'flyer' seems to be availabe. I am trying to determine if the are enough signals on the A1200 ADV101KP30 video dac, for which I have the full datasheet, to drive the blasted AL250 or the newer(?) AL251.

If this is possible, a very economical and low noise, but limited color resolution, internal A1200 SD/FF should be possible.