DFB1 + Nova Falcon Graphicadapter...

[alexh]

ATT20C490 is "looking for datasheet!" I don't know what it actually means?

I think it means that back when the author wrote his driver he couldn't get hold of the datasheet required to support that RAMDAC?

It is available top of Google today.

[markus0321]

SC1183CN and 15025CN have just arrived.
I replaced this original DAC chip on my Tseng board and my PC works in hicolor-16bit modes for 800x600 resolution now! :D
But the SC15025CN does not work in 24bit mode, I wonder why?
Edit:
Of course, for 24 bit I set the resolution to 640x480.
Edit 2:
My Falcon works properly in 640x480x24bit mode with this DAC replaced with SC15025CN!

IMG20230210170516.jpg

IMG20230210170046.jpg

[Wolfgang]

I added routines for DAC detection with my newer drivers. I assume the Windows drivers don't work the same way and therefore don't support 24bit.
There is no guarantee that changing the DAC will work on any given card.

[markus0321]

I added routines for DAC detection with my newer drivers. I assume the Windows drivers don't work the same way and therefore don't support 24bit.
There is no guarantee that changing the DAC will work on any given card.

I also tried with SC11483CN and it also works fine in hicolor mode, in the 640x480x24bit mode it starts but the colors are decoded incorrectly, so your DAC detection method works great because it gives you the opportunity to experiment with different DAC systems :).
These chips cost 8-9 USD in Utsource, so it's probably worth trying.
I have image distortions (damaged pixels, sometimes incorrect letters on the screen) but for me it is not a problem with the jumper I wrote about earlier, it turned out that the problem is the arrangement of the tapes connecting both PCBs of the adapter.
For me, it helps to connect additional ground from the card to, for example, the modulator.

I have another question. Is it normal that the 16-color and 65536-color modes do not work properly on my modified card?

[Wolfgang]

Afair the SC11482/83/84 are 5-5-5 DACs that support 32768 colors max.
I dropped the support of the 16 colors mode a while ago, since it is not any faster than the 256 color mode.
Also when a DAC supports 15 and 16 bit modes, I usually don't put extra energy in supporting both. Often it helps to use the correct BIB file, but it is too time consuming for me to create these files. Thankfully Frank Lukas has invested a lot of time in creating the correct files for most of the cards, but we only have a limited amount of cards for testing new driver versions.

[markus0321]

So my reworked tseng card works fine :-).
At the current prices of these cards, it is worth trying with these DACs. I bought another one with this 8-bit converter and I will also try to upgrade it to the 24-bit version. It is a pity that there are no drivers for Tseng ET4000/32p, these are cheaper and more available, and you can mount 2MB video ram to them.

[frank.lukas]

Problem is that you need with a 2MB W32 card a 120Mhz-135MHZ DAC. I mod a little MACH32 with a BT 85Mhz DAC with a 110Mhz one. But the 110Mhz is not enough. There are in the back days 2MB W32i card in the USA but with a 80Mhz DAC.

https://www.microlabs.com

There are a W32i Nova VME driver but only for 1MB cards and only with W32i chips. W32p are for 32bit PCI or VLB cards I think. The speed is the same ET4000AX vs ET4000/W32i ...

https://forum.atari-home.de/index.php/t ... 398.0.html

[frank.lukas]

Make a Case ...

... but it is not finished yet.

https://forum.atari-home.de/index.php/t ... #msg264576

Alucase_roh.jpg

Deckel_Löcher_passt.jpg

[Badwolf]

It's looking very nice, @frank.lukas!

BW

[JezC]

I have a DeskTopper case that I used to use on my Falcon...but that build by Frank looks much more aesthetically pleasing!

:thumbup: