Scandoubler recommendations

[Daedalus]

Hyperspeed wrote:
@Daedalus

So only external scandoublers have this 8:4:4 colour limit? I can't
say I notice it in NTSC but I did in PAL mode. I also got noticeable
vertical lines down the screen no matter how much I adjusted the
potentiometer on the back.

AFAIK, I don't have that trouble with my internal one on my 1200, but I do know the external ones use an extra A/D stage, and it's that that isn't capable of reproducing the full AGA palette. That would add significant cost to the device, and for the majority of cases isn't required.

[Jiffy]

srg86 wrote:
50Hz hmmm.

On my PC, I see flicker at 85Hz refresh rate on plain white. This is enough to cause me eye strain. I run my PC monitor at 100Hz.

I do have one 1989 VGA 14" VGA monitor that afaik is single sync (it has black border arround the outside of the screen so the picture doesn't fill it). at 60Hz I don't see flicker, strange.

Could this cause me problems with scandoubled Amigas on PC monitors.

Flicker still can be seen at 50 Hz on my Amiga 1200. The more recent your CRT, the more you will notice the flicker: old CRTs were made for 60 Hz and therefor had slow decaying phosphor. Current CRTs are often made for 100 Hz or more and thus use much faster decaying phosphor. The netresult is that on the latter screen, flicker will be (much) more noticable when running it @ 50 Hz compared to the older screen designed for 60 Hz operation. Nevertheless, I find my internal flickerfixer in combination with my Compaq V50 15" CRT a perfectly acceptable solution: no more 'black lines' in non-interlaced resolutions, better colours and a very usable high-res/interlaced resolution (I have my workbench set to high-res/interlaced with full overscan).

The 50Hz flicker is ofcourse still noticable: my PC (with 19" Iiyama and Matrox G550) ofcourse has a (much) stabler picture.

If you don't like a pc screen @ 85 Hz then you won't like an Amiga workbench @ 50 Hz. Then again, a high-res interlaced screen @ 50 Hz on a SVGA CRT is _much_ nicer to look at than a med-res non-interlaced screen @ 50 Hz on a 1084... :-D

[Jiffy]

srg86 wrote:

Also, those of you with it fitted it in Desktop A1200s, I was wondering where you put the VGA connector. Have you made a hole for it above the other ports, or possibly left it dangling on it's lead outside the case.

It connects through a small flatcable to the RGB video out of my Amiga 1200 (it is designed to fit here). To be honest, I never questioned its position and thus never wondered if it would work without it being connected to the Amiga's RGB port. Certainly something worth trying, though.

I was also wondering about that little plate on the left hand side of this image (it would be beneith the floppy drive), would the lead reach to mount the vga connector in that? Looking at A1200 motherboard pics, it would seem that it's unused.

Normally, it is indeed unused. The Blizzard SCSI card uses it for the external SCSI connector and there is/are also soundcard(s) which use it.

It would most likely not be ideal to use it for the flickerfixer's VGA connector as the internal flatcable would have to be replaced by a much longer one and I don't know if that would have a nice effect on imagequality...

[patrik]

Daedalus:

The internal DCE ones as well as the CV64/3D scandoubler does have the 8:4:4 limitation. The reason for this limitation is that it only needs 2/3 as wide/much buffer-memory that way (16-bits wide for 8:4:4 instead of 24-bits wide for 8:8:.


/Patrik

[Doppie1200]

It connects through a small flatcable to the RGB video out of my Amiga 1200 (it is designed to fit here). To be honest, I never questioned its position and thus never wondered if it would work without it being connected to the Amiga's RGB port. Certainly something worth trying, though.

That is with a desktop version of the flicker fixer. The tower version does not connect to the RGB port. The flatcable leads to a VGA connector. You can see this on the pictures I posted.

Normally, it is indeed unused. The Blizzard SCSI card uses it for the external SCSI connector and there is/are also soundcard(s) which use it.

It would most likely not be ideal to use it for the flickerfixer's VGA connector as the internal flatcable would have to be replaced by a much longer one and I don't know if that would have a nice effect on imagequality...

The default cable delivered with the tower version is long enough to reach it. Since amiga is not capable of very high dot clocks the signal does not suffer. At least I did not notice anything.

[Hyperspeed]

I can't believe this!

So even DCE were selling these things knowing they were cut down and
saving themselves extra buffer chips? When I bought mine I complained
that I was getting 8-Bit colour but the shop just ignored me and told
me to live with it.

I'm curious about NTSC though, PAL was pretty rough but I seem to be
getting perfect display from NTSC/PAL 60Hz. I do notice a slight
banding on smoothe gradiants but I put this down to 19-bit HAM8 as
opposed to 24-Bit True-Colour.

So are you sure even the INTERNAL scandoublers/flicker-fixers were
limited to 8:4:4?

:-(

What about the Picasso-IV, I know Amiga Format rated that much more
highly than the CyberVision 64/3D's flicker fixing ability.

[Doppie1200]

Sadly it is true. I checked it by connecting both my 1084 and svga. The copper sky on xtr-racing is different.

If the DCE flicker fixer would use 16 bits colour that would explain the effect. It would not be able to mix all the colours needed to produce the gradient.

So; after this thread I can summerize this about an internal scandoubler:

Minus:
-Could be a hassle to fit inside
-Does not reproduce all AGA colours (16 bit)
-Has a tendancy to get hot

Plus:
+Interlaced modes are rock solid
+Use of most VGA monitors (which has alot of advantages on its own)
+Access to more screen modes (15..31kHz)

Sure this list can be enlarged. Maybe this can turn into a FAQ or something.

[Jiffy]

Doppie1200 wrote:
So; after this thread I can summerize this about an internal scandoubler:

Minus:
-Could be a hassle to fit inside

All is relative, ofcourse. My internal scandoubler/flickerfixer was easy to fit in my desktop A1200, when you take in mind the upper shielding had to be removed and the harddisks cradle also didn't fit. Nothing a small piece of cardboard couldn't fix... ;-)

-Has a tendancy to get hot

Seems not to be a big problem. The chips on the flickerfixer are _very_ tolerant to high temperatures. Apart from that, I have a 2.5" 4 GB harddisk put on top of the flickerfixer and there's only a slight increase in temperature on the outside of my A1200 at the spot where both harddisk and flickerfixer are placed. My Blizzard 1260 is much more of a heatsource.

Plus:
+Interlaced modes are rock solid

'Rock solid' as in 'compared to normal interlaced modes', ofcourse. The flickerfixed image is still only 50 Hz (PAL) and a slight flicker can therefor still be noticed. The better your CRT, the better it will be noticed.

All in all, I am very satisfied with the unit:
- if you're not to shy to open up your A1200, it's an easy fit;
- much improved imagequality;
- no heatingproblems;
- you can use a standard (S)VGA CRT.

BTW: is there anyone with any experience connecting a TFT to a flickerfixer? I like the idea of connecting one to my A1200, but don't have one handy to test the result. I know, high-res interlaced doesn't compare to well to a TFT's native resolution and most TFTs prefer at least 60 Hz. But I still would like to know... :-)

[srg86]

Right, I've got my Amiga and my dad and I have fitted the internal scandoubler in a similar fashion to Doppie1200. First of all PAL modes are completely fine. I can't test the different screen modes yet because the prefs didn't work on the existing hard disk installation which was almost trashed anyway. I can't reinstall workbench because the disks are foobar'ed and won't even boot. Other disk are the same untill formatting. I've ordered another set of disks to use but if I have troubles with these then the drive could be out of calibration (need new drive).

Anyway, through the scan doubler, in a workbench screen (booted from HDIntall disk) I'm finding that Whites are slighly off, they have a slight yellowish tinge to them. Could this be because of the reduced colour pallette, is it because of the relative darkness of shadow mask monitors? Or is there something I've done wrong?

srg

[srg86]

Doppie1200 wrote:
Sadly it is true. I checked it by connecting both my 1084 and svga. The copper sky on xtr-racing is different.

If the DCE flicker fixer would use 16 bits colour that would explain the effect. It would not be able to mix all the colours needed to produce the gradient.

So; after this thread I can summerize this about an internal scandoubler:

Minus:
-Could be a hassle to fit inside
-Does not reproduce all AGA colours (16 bit)
-Has a tendancy to get hot

Plus:
+Interlaced modes are rock solid
+Use of most VGA monitors (which has alot of advantages on its own)
+Access to more screen modes (15..31kHz)

Sure this list can be enlarged. Maybe this can turn into a FAQ or something.

Mainly because of this minus:

-Does not reproduce all AGA colours (16 bit)

I've decided to sell my DCE internal flicker fixer, I was thinking in the range of about £50.

BTW With my Doppie1200 like A1200 mod, it didn't get that hot at all.

srg

[Doppie1200]

Well, maybe I have one that likes to get hot then  :lol:
Anyway I feel better about the heatsink.

The 16 bit limitation does not bother me at all. It is hardly noticable in most games. The other improvements are more impotant to me. But that is a matter of opinion.

Good luck.

[Karlos]

Well, any pre aga games will look just fine with 4-bits per gun anyway.

I still think RGB 844 was completely the lamest choice imagimable. They really should have used some sort of proper 16 bit 5:6:5, or if such quantization was not possible then at least give 8 bits to green.

[Hyperspeed]

That was a good summary Doppie.

:-)

I was always suspicious about my colour palette in relation to 24-Bit
but it doesn't make much difference between 16-Bit and 19-Bit HAM8.

The reduction was more noticeable in PAL 50Hz than in PAL 60Hz for
some reason though.

So if the internal scandoublers have the same limit with colours as
external, what exactly are the benefits of an internal scandoubler?

1)Hassle to open up the Amiga
2)Can't use it on different machines like CD32/CDTV
3)Can't swap it between your Amigas in emergency
4)Could heat up your motherboard and hard disk


Why not the easy plug-in external one? In PAL 60Hz (/NTSC) you lose
next to no quality at all.

The only downers about the external one are:

1)Protrudes 3" from 23-pin port
2)Blocks 23-pin from RGB Scart/Genlock/Grafitti card
3)Slight loss of picture quality (only noticeable on mesh patterns)

:-)

Would it be fair to say then, that the Picasso-IV is the SUPREME
scandoubler/flicker-fixer with full 24-bit pass-thru of AGA in HAM8?

[Doppie1200]

Thanks, but as others say it is all relative. If you don't mind a DIY project, or if you cut some corners an internal is no hassle to install.

Anyway what benefits are left. The biggest benefit would be the solid conversion. It takes the digital signal from the chip.

The two biggest flaws identified are indeed colour limitation and inflexibility. You cannot hook it up to your A600. As for heat, I seem to be the only one seeing the need for the heatsink  :-P.

If I could get an external one I still would. Not as replacement for the one I just built in but for my other miggy's (A500 and A600).

I think this thread has become very resourcefull for someone wanting to know something about scandoublers. We should rename it to 'all you ever wanted to know about scandoublers but was afraid to ask'-thread  :lol:

[Jiffy]

Doppie1200 wrote:
Anyway what benefits are left. The biggest benefit would be the solid conversion. It takes the digital signal from the chip.

This for me is a big pro: I've seen the image on several internal and external flickerfixers for different types of Amigas during time and I find my current one to have a nice & stable picture. Much better compared to, for example, my Multivision 500 of the early nineties...

The two biggest flaws identified are indeed colour limitation and inflexibility. You cannot hook it up to your A600.

Indeed. Again, this is personal. In practice, I hardly notice the colourlimitation (I come from the A500-era, so the 8:4:4 is still quite an improvement).

As for inflexibility: I prefer to put my computersystems together and leave them like that. My other Amiga is a 2000 and I'm not going to rip that one apart to take out, for example, my X-Surf II or my Multivision 2000* just because I need it on another Amiga...

*which currently is not being used as I 'only' have a 1084 to connect to my 2000.

I think this thread has become very resourcefull for someone wanting to know something about scandoublers. We should rename it to 'all you ever wanted to know about scandoublers but was afraid to ask'-thread  :lol:

:-D

[Tahoe]

Excellent thread guys!

All posts here refer to the the DCE Internal Flicker Fixer. I am considering buying the Eyetech one. Is this identical to the DCE? Not according to some old reviews I dug up.
Would this also suffer from the 16bit limitation?