REQ: Someone Mass-Produce Scandoubler/Flicker Fixers

[alexh]

Myself and Jens Schoenfeld of Individual computers are trying to bring back the Indivision external scandoubler / flicker fixer which used to retail at 99 euros.

The problem is trying to get hold of 250 pairs of chips that make up 1/2 of the device, they are both no longer manufactured, so I am trying to contact some people in china.

I will try my best to help Jens bring this part back to you.

[J-Golden]

THANK YOU ALEXH!!!!

I started a thread (most of all the SD/FF threads of recent actually) asking for this and I'm SOOO glad people w/ power are looking on.

J-Golden

[xaccrocheur]

Mm. I just checked the mailbox, nothing innit yet. Don't get too excited  ;-)

[Cefa]

alexh: What do you think of my idea of doing the scandoubling and flickerfixer in software (using a pci card on the PC ) to cut down on chips as much as possible. Using a clip that attaches to the chips inside the Amiga like the internal scandoublers. Although making a pci card with just a buffer without a ADC could be expensive

It would be cool if you could connect them using USB2 or firewire but they are problably to slow.

Cheers

[Dr_Righteous]

@alexh

Bingo! Precisely what I was hoping for.

[alexh]

We just have to wait to see if any of the people who CLAIM they have stock of the DAC and ADC chips originally used on the indivision actually have any.

No, I doubt Jens would design another using readily available chips, he's got too many of the PCB's, plastic cases and other chips.

No, I dont know how long after Jens gets the chips he will manufacture them.

No, I dont know how many he intends to make, but I volunteered to help him source the chips and he's asked me to try to source 250 pairs of chips.

Jens has been trying on and off to source these chips for 2 years without success. Lets see if anything happens.

[Zac67]

Just wanted to add: what most of you keep forgetting is, that a generic scan converter/doubler will sample the horizontal scan lines at arbitrary intervals - that's why the output's usually pretty crappy.

For reasonable results, the SD must sample the pixel right where Amy's putting them (at pixel clock intervals); it must be adjustable and/or automatically synchronizing to the pixel stream (like most TFTs do w/ PC like pixel streams) or the resolution must be so extremely high that no pixels are cut in half. If you don't understand what I'm talking about, look at a FF that is tuned way off (little screw): some pixels are doubled, some are missing, some even flickering - not a pretty sight.

That said, I don't believe there are many (if any at all) non-Amiga scan doublers around that are of any use.

[Johan Samuelsson]

hey! i want one too!

i even spoke to gunne/ggs data and tried to get him to co-op with individual computers to manufacture one! =)
i just wrote him a mail and tipped him about this thread.

edit: just tossed away a mail to individual computers aswell, let's see what happens.. .

[xaccrocheur]

@Zac67 : That's exactly what I had in mind, but was unable to word. All external FF that I saw produced that pixel mess that you described in technically correct terms. A FF/SD (still don't know the difference, if any) that would sync the way you described, is the thing I'm willing to actually buy if it's ever produced.

[Zac67]

Well, I use Flicker Fixer for special Amigaish hardware and Scan Doubler for more generic hardware that converts incoming 15 kHz Video to 31+ kHz - that's according to general use as the term Flicker Fixer is only known to Amigans, while Scan Doubler or the more general Scan Converter is widely used for various video hardware.

What I was wondering about since the thread started:
Lots of current PC graphics cards have TV-in connectors. These inputs are sent through conversion ICs that produce YUV (RGB?). It might be possible to put in Amiga video and have it overlayed full screen to any screen mode the card can produce. While this would be a cheap scan converter (of lesser quality of course), using a PCI board in an Amiga w/ Medicator etc would yield a decent RTG board as a 'side effect', so quality of FF'ed video would matter too much. That way you could run native, scan converted screens in a window or full screen for games and use the RTG for work. How does that sound? Anyone here having hardware knowledge of nVidia / ATI / Matrox chips?

[X-ray]

@ alexh

Would the final product that Jens makes be 24 bit or would it be 16 bit?

[JimS]

Cefa wrote:

It would be cool if you could connect them using USB2 or firewire but they are problably to slow.

Cheers

I thought of that too... I'm sure either USB2 or firewire would be fast enough. I've seen a couple FPGA boards that program through a usb2 port, and can transfer data via usb as well.
nice to think about anyway.

opalkelly.com

[Zac67]

I guess Firewire or USB would produce too much overhead for graphics to run smoothly. Of course it's possible since there are USB port replicators including VGA ports, so they must include a complete graphics adapter.
OTOH, this is no FF/SD but an RTG card...

[Cefa]

Yeah but those card probably are doing some kind shortcuts. Like the video usb card i saw which only supported 320x240 resolution USB2 and firewire are probably to slow remember that the Amiga sends out 50/60 Hz every second which you must somehow take care of. Thats why i would like to have a simple PCI card which buffers the signals and sends them to the PC, Pegasos, AOS4 whatever. Then you write a scandoubler/flickerfixer in software and using maybe the mplayer sources as guide or using them directly.

But i dont have the skill (PCI cards arent like easy ISA cards ) nor the money to do it


Dak’kon: "Strength lies in *knowing* oneself.

Cheers

[JimS]

I did a quick & dirty calculation, and figure that an Amiga screen, assuming overscan and sending over the 12 bits of screen data would only need 1/4 of the USB2 bandwidth.

BTW, over on "Hack a day" there's a link to a guy who did hack a pci interface... of course he cheated by not following a number of the PCI rules..

[Zac67]

Dunno what you calculated with, but SHires AGA lines have appr. 1450 pixels/line x 15625 Hz x 24 bit = 544 Mbit/s - a bit too much for USB 2.0. But just how did you want to get to the video data into USB2?