New Scandoubler ready!

[alexh]

mike- wrote:
Didn't it turn out that the doubler supported 24-bit?

Absolutely NOT.

[alexh]

TheDaddy wrote:
I am confused.

Does it or does it not support 24 bit? :-?

WTF? What part of "Absolutely NOT" gets you confused? :-)

[alexh]

Yes it is an absolute.

The unit is based on the reference design for the Averlogic scandoubler chipset found in a lot of low cost LCDTV's. The AL250A and the AL875 which is not a 24-bit system.

This has been discussed time and time again.

With AGA games you will get some colour/detail loss.

Plus it is an external scandoubler which means there is Digtal->Analog->Digital->Analog conversion which never offers the top quality!

The prototypes had unsheilded ribbon cables which made things even worse.

But as has been said for $65 you cant complain ;-)

[alexh]

redrumloa wrote:
I also don't think interlace modes will display on LCDs with my current unit.

If your LCD supports 50Hz vertical sync it will.

[alexh]

It wont receive 24-bit colour, no.

RGB565 input only and AGA is RGB888

[alexh]

Nlandas wrote:
Correct me if I'm wrong but all AGA games would be supported by that?

I'll correct you. You are wrong.

Nlandas wrote:
(They were all 8-bit were they not?)

Crap not another person who doesnt understand the difference between palettes entries vs colour depth ;-)

AGA is 24-bit. It has 256 palette entries each 24-bit.

How badly affected a game would be obviously depends on the 256 colours the game uses. If it uses lots of subtle shades of one colour the effect will be much worse than if it uses lots of widely different colours.

Nlandas wrote:
It'd be certain HAM modes and demos that would not be supported fully - correct?

Wrong. All AGA modes not fully supported.

[alexh]

Nlandas wrote:

alexh wrote:
Crap not another person who doesnt understand the difference between palettes entries vs colour depth ;-)

I am amazed every day at the number of really nice and helpful people here on Amiga.org and the number of rude ones.

Heh, you see the smiley winking face at the end. That indicates that the previous sentance is _sarcastic_. It was actually dig at -D- who asked me the same thing in a different thread several months ago.

Edit: Oh, I am so sorry! Sincerest apologies. I just noticed you were an American. You dont have sarcasm do you? ;-)

Nlandas wrote:
Indexed color was always confusing to me. I roughly understand the the on screen palette of colors is selected from a "master" 24-bit palette and can be changed at any time affecting the whole screen.

Perfect description.

Nlandas wrote:
However, I never understood how a 16-bit "master" palette couldn't be changed on the fly as well to accommodate the actual colors selected for the smaller on screen palette.

The scandoubler and the AGA chipset are not coupled in any way. The graphics have already been converted from 8-bit indexed to 24-bit direct colour by the time they arrive at the scandoubler. It does not matter that there are only 256 different colours, there is no way the scandoubler can know this, or do anything about it if it did! It just has a direct colour input. What you put in is what you get out and because the full 24-bits cannot be fed into 16-bits, the least significant bits (LSB) of each colour component (RGB) are not connected. Colours which were distinguished by these lost LSB's are now indistiguishable from others.

A 16-bit "master" palette as you call it can never display some of the colours contained in a 24-bit master palette, the information is lost.

Nlandas wrote:
The AL875 chip already outputs 24 bit.

The AL875 is an unremarkable chip. It is just a 3 channel ADC. There are lots of similar chips, from other manufacturers.

Nlandas wrote:
The bottle neck is the AL250. If I can find a 24 bit replacement who knows

Unfortunately when the colourspace is Chroma/Luma (found in CVBS / SVideo)16-bits is more than enough for accurate colour representation, this is why most chips just have 16-bit inputs :-( You're gonna find it difficult to find a chip which is as cheap as the AL250A or as integrated for the money. You could easily make your own 24-bit scandoubler with a CPLD and some RAM (akin to the internal DCE Flicker Magic) but the cost would go up to $120+

[alexh]

You know what? I'm going to take back some of the things I said about you Americans ;-)

Nlandas wrote:
That's probably why Roy chose it.

I *think* his box is based on the Averlogic developers board that they ship to potential customers. Naturally it has as many Averlogic chips on it as possible.

And perhaps there is a price break if you buy the two (AL250a, AL8375) together?

I still stick to my guns and say there is no real profit to be had in making scandoublers just for the Amiga.

Internal scandoublers (the best kind) would need at least 3 different PCB's  (A500, A2000/4000, A1200) unless you indend to disappoint some people. All adds to the R&D cost.

We'll see :-D

[alexh]

It would put potential buyers minds at rest if they knew if your new scan doubler would work with an Elbox Fast ATA with a riser and if the two would fit together in an A1200D desktop case.

If you don't own one, could you see if AmigaKit would kindly lend you one for testing?

[alexh]

All that have analog VGA inputs.

[alexh]

Schoenfeld wrote:
Production start by the end of this month [April 2008], availability in summer, target price 129,- EUR each.

Any news?

[alexh]

ManRaven wrote:
Nice pics but it's all in German.
Can anyone paraphrase it into English?

[alexh]

Jens, if you ever read this, regular updates would keep potential customers from going with an inferior, but available solution.

[alexh]

The circuit diagram is useless without the code stored within the programmable logic chips

[alexh]

It will have it's own VGA connector just like any other internal scandoubler.