automatic monitorswitch for any graphiccard

[Crumb]

@Ratte

your board looks promising! BTW, a friend of mine had an automatic external switcher on his A3000 with RetinaZ3, it worked with CGX without any special patch, it seems both CGX and P96 set vsync/hsync to a constant voltage level when Amiga screen is active (at least using certain tooltypes), wouldn't be possible to detect when vsync&hsync are in that state in the gfx card?

Wouldn't be possible to give priority to one of the outputs (Amiga) output unless vsync&hsync are set to certain level in the gfx card output? In the worst case I think it would be possible to read the signals from the VGA Feature connector located in many gfx cards (with the exception of CVisionPPC/BVisionPPC)

http://tech.groups.yahoo.com/group/Amiga-Hacks/message/1427

"both CyberGFX and P96 have
such a function but realized in a more clever way: a sync signal (V or H) is
set to a costant voltage level when an Amiga native screen becomes frontmost.

But this system is depending on the chipset used by the board: normally all
those support DPMS are able to set the sync signals this way.

There are some commercial switchers available that work this way: the Javosoft
one, the Eyetech one and one for the Retina card.

Strangely this feature is not documented on the RTG manuals."

[Crumb]

Retina V-Code Switch is limited to the V-Code Module of the Retina.
The V-Code is converting the Retina Image to S-VHS and Composite-Video.
The V-Code Switch is an Extension for the Extension (Sandwitch) for the Retina.
And it works only with 15kHz Modes and needs min. Retina Software V2.2

My friend was using CGX that's for sure, his box was black instead of white the VCode external box photographs I have seen but perhaps V-Code was also produced in an external black box version and CGX supported it. His Monitor was a 1960 so that would make sense.

But for your information ... I allready played with this idea.
Jens also gave me the H&V-Sync hint.
You can see a separate 10pin header on the special Radeon-Switch (next to the extra manual switch connector).
http://www.a1k.org/forum/showpost.php?p=302777&postcount=1 (last picture)
They are delivering H&V-Syncs, Vcc, GND and the Select-Line.

Did it deliver better signal quality? It looked very nice too (although current model is delicious)

Specialdesign for prototyping this way ... played with the idea of a Maxim-IC, but it is EOL and I dropped the Idea.
On the other side my software is working like CGFX and P96 did it.
I had the chance to talk with Frank Mariak (CGFX) on a PowerDev-Meeting and the way I controlled the switch is identical to the CGFX-way for Cards with inbuild-switches.
We were snooping the same systemfunction ... the only difference is, that Voodoos, CVPPCs, Radeons didnt have a separate signal line for a switch signal.

My point was that perhaps there was some chance of generating yourself the "select line" scanning the values of gfx card hsync&vsync signals and enabling it when the values of these signals imply aga output should be enabled instead of using a software patch (don't take me wrong, I don't have a clue about electronic and my questions are pure curiosity, your solution is still very elegant)

So I had to take a signal from the CIA 8520 for this.
And the best choose seems to be the CTS-Signal from the Serial-Port, but it is also possible to use the Select-Line from the Parallel-Port.
But I think that there are more Amigas with parallel printers out there, than Amigas with serial modems ... thanks to LAN and DSL.

If the hsync&vsync signals change to certain value when an amiga screen is being shown perhaps it may be possible to generate the "select line" using some extra logic (the disadvantage would be that circuit would become more complex). Your approach sounds very reasonable for 68k but for OS4 I guess some stuff could be left out of kickstart layout file so it works like 68k version too. Booting MorphOS may be interesting too... does any of your testers have PPC boards?

All in all your board looks sweet, thanks for taking care of amiga community, many users really need this! :-)


PS: what's that PaulaPlus stuff in one of your videos? :-)

[Crumb]

PaulaPlus is a joke .. like the complete DONOP movie.

oh! what a pity! ;-(

Regarding the H&V-Sync, the idea isnt bad. I loved the idea, too.
But searching for some shematics or ready-to-use DPMS-ICs showed off some problems.
These ICs take a while to switch the signal, DMPS allways waits some seconds before the signal will be switched.
Sitting in front of an Amiga and waiting for arround 5 sec. for a screenchange isnt very funny ...

Oh I see... then I guess ready to use DPMS-ICs would have to be ruled out since the wait would be too long. A custom circuit would be required that doesn't wait so much time.

PPC development isnt possible for me, my CSPPC got lost at Vesalia in 2001.
I have no change to get some HW back (I tried many times).

Sad to hear that :-/

For those OSes (also 68kDebian or LinuxAPUS) you can add a manual switch, to override the "software" setting.
(1-0-1 switch = software controlled - hardwired aga - hardwired gfx)

That would be a very good solution :-) Do you plan to sell the parts and the board as DIY kit?