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Author Topic: NTSC DCTV work on PAL Amiga?  (Read 6121 times)

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Offline Motormouth

Re: NTSC DCTV work on PAL Amiga?
« on: July 30, 2011, 04:33:52 PM »
Quote from: T3000;618995
DCTV really needs 2mg chip ram to work properly. A stock 500 will struggle tremendously with DCTV setup and stomp all over your funtimes. I tried long ago and ended up running it on an A2000 with 2mg chip, Supra28, 8mg ram, harddrive, etc. A second monitor for the output is also handy as the DCTV unit displays a composite signal. Not to mention, the capture is a slow scan and not an instant grab. The paint program was awesome for it's time.
Good luck.

Why would the DCTV need 2 meg of chip ram?  

The DCTV came out before the A3000 and 2 megs of chip

The DCTV uses the same 3-bit and 4-bit plane IFF that the Amiga uses.  The memory usage is similar to any standard OCS/ECS 8 or 16 color IFF hires or hires-interlaced image.  The decompression is done on the fly and does not require CPU.

The first line of the image has the compression information that the DCTV uses.  Just about any iff viewer, including deluxe paint, can be used to view DCTV compressed IFFs, as long as it shows the first line of the image.  However in you want you manipulate DCTV compressed IFFs you need a DCTV compatible paint program or image converter (like ADpro).

1 meg of chip is more than plenty for image viewing.  I used a DCTV with my A500 with 1 meg chip for years without any problems.  In fact you probably get away with 512k of chip ram.  If anything you probably need some fast ram.  A 1meg chip/2meg fast ram A500 or A2000 with a stock 68000 works just fine.

Where things get screwy with the DCTV is digitizing.  some 030, including the A3000, had timing problems with the digitizer.  This was suppose to be later fixed in software.

I do agree a second monitor is nice to have with the DCTV or RGB/composite button on a A1084 works well.
« Last Edit: July 30, 2011, 06:07:28 PM by Motormouth »
 

Offline Motormouth

Re: NTSC DCTV work on PAL Amiga?
« Reply #1 on: July 30, 2011, 06:25:15 PM »
Quote from: XDelusion;652249
Well here's what I just amassed to play with:

SuperGen and SuperGen +
ChromaKey + (with blue screen).
DCTV
DCTV RGB Adaptor
Cannon Camera (actually I've had that for a while)

All NTSC, both my Amigas are PAL. Might have to buy a NTSC A600, will see.


All my Amigas are NTSC and my DCTV is NTSC, but my guess and this is only a guess, is the difference between and NTSC and PAL DCTV is probably on the Digitizing end, as timing is important.

Again I am guessing, but image viewing would probably be the same whether the image is PAL or NTSC.  It has been years since i used my DCTV, I should bring it out of storage, but I think I could display both PAL and NTSC  hires/ hires-lace on an A1084 monitor with it.