Scandoubler recommendations

[Doppie1200]

Hi,

Recently I aquired one of those DCE internal scandoubler/flickerfixers.

It is a pcb that is clipped over Lisa.
The thing works great. The smallest chip on the pcb does get rather hot.

I'm in the progress of installing it in my desktop A1200.
Next week I'll be adding passive cooling to the small hot chip. The harddisk will be moved to the right. I'm modifying the tinware to make all this possible.

Anyway to make a story short;
An internal Scandoubler/Flicker fixer is difficult (and a lot of work) to install proparly.
If you are not a Do It Yourself (DIY) man I would not recommend it. If you are, an internal is definatly the best (matter of opinion). If you're not try to get an external one. An external can be used on other miggy's too that might join your fleet in the future.

Good luck.

[Doppie1200]

@Brain

No I'm not kidding. But perhaps you found an easier way.

I need to relocate my hardrive because it does not seem to fit at it's original location. This can be very tricky. Also I want the original tinware inside to remain as intact as possible.

When I succeed I'll post some pictures of the interiour of my machine.

[Doppie1200]

I removed the cap displayed on the far left of your photo.

An old VGA card was sacrificed and I modified the PCI bracket so it would fit nicely.

I can take photo's of it if you like and email them to you.
(or post pictures here if interest exists)

Anyway I got that idea from anouther thread about this which I started. Maybe you can read more about it there.

Avoid cutting up the plastic outer cast. It wil never turn out to be as straight as you imagine it to become when you start

[Doppie1200]

hehe, I'll take some pictures tomorrow.

BTW, beware that a modern vga is very very very sharp. It makes games look pretty ugly sometimes. That is because some effects relying on the blurry 1084 screen do not work anymore. Looks really like those old 320x200 games on PC used to look.

But I love the 640x512 flickerfree desktop  :-o
Haven't played around with it enough cause my mod is not finished. Harddisk is still not relocated.

[Doppie1200]

Hi,

I uploaded three photo's. The mod I'm doing has progressed a little further than is displayed by the photo's. A passive cooler has been glued on the small ic in the lower right corner (used special thermo glue). The tinware has been adapted to fit nicely again and the harddisk bracket has been relocated.

All I need is to drill holes for the harddisk in the harddisk bracket and tinware. Then I'm done.

The photo's do not seem to appear yet. I quess the have to go by the moderators or something.


@x56h34
I think games look bad cause of the incredible dot pitch of modern crt's and the scanlines gone missing :-o
Find a poor quality vga and it all look 1084 again.
I usually take of my glasses.

[Doppie1200]

Hi,

I dont think the heatsink is really needed. Although the chip is getting very hot and is managing to warm up my heatsink pretty good. But alot of people are using these devices without one. I choose to release the straign on the chip. First I downloaded the datasheet which states the chip brakes down at a junction temprature of 150 degree (C). So I knew it would be safe to skip the heatsink. Hoewver I choose against it in an attempt to lenghthen its life.

When you can still toutch the chip without burning you can be sure the junction temprature is below the stated maximum. It's beyond the scope of this reply to explain junction temprature and I'm not the best person to explain it to you.


I'll post the pics of my finished mods tomorrow. The photo's are already taken but I am in no mood to get them off my camera right now

As for cutting the case. It is a matter of opinion and guts I guess. I would avoid it at any cost since it will never look as straight as something out of the factory.

As for hot glue guns. I got mine for a dime at a local DIY store. Take a look around. You need no military spec. glue gun to do this kind of project

BTW This is my first message posted with a real A1200 by me on amiga.org. That scandoubler is working great!

[Doppie1200]

Hi all,

I posted the pictures of my mod. They should appear when the moderator clears them of all offensive language  :lol:

Anyway I have a stock 17" XGA with OSD and stuff. It works really nice on 49.9 Hz. Perhaps I lucked out.

It is true that VGA is supposed to be 60 Hz.

When I get around to it I will try my 15" TFT. But since it is only 1024x768 I doubt it will get the amiga screen good on the display. The Amiga screen is 640+overscan by 512+overscan. I doubt this will be a multiple of 1024x768.

[Doppie1200]

Thanks! I'm a bit proud of it myself.
The scandoubler does fit under the tinware. The tallest chip touches the tinware though. I checked if it would short anything out but it wouldn't. However you cannot place the harddrive and the tinware on top of the scandoubler. That will not fit. Perhaps leaving off the tinware would make it fit.

As for instability. I'm having alot of instability. Freezes, crashes or sudden reboots.
Since my previous A1200 has the same trouble I'm suspecting the fastram on my accelerator.

If the trouble I'm having is related to the heat from the scandoubler I'll keep you all posted.

[Doppie1200]

The motherboard is untouched.

Extra slids were cut to let the shortened legs through. The legs where shortened to about one millimeter. I glued a strut under the tinware that rest on the motherboard. This provides extra strength. The tinware would bend towards the motherboard since the slids weakend it and it is not designed to carry the weight of the harddrive.

The extra holes were cut so a modern drive can be fitted.
These drives have screws on the front and back rather than in the middle. If you use an old drive you need no extra holes since the screws will be where the clock port expantion is to be. I would recommend to INSULATE the clockport header since the old screw holes are directly above the header. The head of the screw might short your address/databus sending another amiga to the recyclers.


[EDIT] The stability problems the A1200 had were not related to the mod. It was software related.

Take care!

[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.

[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.

[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.

[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: