These look interesting. Got a few questions for you.
-It looks like this is an up-to-date version of th A520 adapter (minus the now-useless RF stuff). Is that a fair assessment?
-This is probably my most pressing question: Let's say I have an NTSC Amiga. What happens if I put the Amiga into a PAL screenmode with this device attached (or vice versa)?
-And if weird things happen per the scenario above, can the NTSC/PAL switch be toggled while the power is on? Any chance of an autoswitching version in the future?
Thanks, and thanks again for your development work!
Hmmm, I'm not quite sure how to answer the first question :-S The old A520 uses a Motorola MC1377P , which needs more supporting circuitry to work, from memory. Amazingly, this IC can still be bought new! I remember looking at the datasheet, and thinking, nah, the AD724 is easier to implement. I actually looked at the data sheets of several video encoding IC's, and ended up coming back to the AD724, due to ease of use. Also the fact that my supplier had them way cheaper than anyone else convinced me. So I would have to say other than taking the RGB and SYNC signal(s) from the video port, and changing them into something else, it has nothing in common with the old A520. I was not thinking of the A520 when designing the PCB. The whole saga started some time ago on EAB actually. A guy with the nick of "narmi" started a thread about a home made adapter he made based on the AD724. After more than a year I think, still no one had made an adapter for the masses, as far as I can tell. I actually forgot about it for a while, then remembered, so I checked out the thread again. Since I had
lots of free time on my hands, I made the decision to make my own adapter. The result of my labour is what I am now selling
With your other questions, I can only answer partially. I have only PAL Amigas, but I did switch to NTSC for testing purposes, and out of curiosity. Colours were normal, but the image looked stretched, or elongated, maybe zoomed in. My TV is also PAL. I think it can display NTSC as well, although I am not 100% sure. I have watched an NTSC DVD with no problem on it. But this could be my DVD player doing the work. I don't have any NTSC software to test either, after switching the Amiga to NTSC mode. I can't remember if switching to NTSC mode made any difference, with PAL software, or just the boot screen. It may depend on the circuitry of the TV, in how it tells the TV to display the image. It may squeeze it to fit, simply crop a bit off (which seems common) (NTSC), or stretch it to fit, as mine seems to have done (PAL) - but this is just speculation. I couldn't say for certain, unless I also had an NTSC Amiga and/or NTSC TV powered by 60Hz AC? I could try playing around with NTSC display on my PAL setup and taking notes this time if you like
I'm sure there are people that actually know what they are talking about here on Amiga.org, that could tell us what to expect
I also tried switching between PAL and NTSC with everything on. It didn't seem to do any harm, but maybe it is not wise to do it often? So I think one could try it, to see what the differences are immediately, if curious.
As for autosensing, I doubt it. I want to keep the hardware cheap and simple. By adding more IC's and supporting circuitry, this will make things more expensive. Also, to be honest, that is not something I have bothered to research, so I don't even know how I would do it
