ferdimh@gmx.de wrote:
On 10 Jan., 21:29, "Michael J. Mahon" <mjma...@aol.com> wrote:Jerry wrote:I recently bought a Benq FP241W LCD monitor since my old Dell 19" CRT was dying. This new monitor has all sorts of inputs, including an NTSC RCA jack, plus individual R, G, and B RCA inputs. I haven't tried my IIgs on it yet, but an Apple IIc works quite well. There is a very slow roll to the image, but it's quite usable even in 80-column mode.What, exactly, is a "very slow roll to the image." Does the image position change on the monitor? Does a small "ripple" move through it? I'd like to know more.I think it is one of these: 1) The whole picture rolls very slowly as if it was out-of-sync. 2) The picture rolls 1/4 to 3/4 over the screen, then jumps to the original position where it starts to roll again 3) The picture jumps up and down very rapidly. I've seen all of these on different digital displays.
Yes, those are all possibly described as "roll" (though 1 and 2 are the most likely)--but I would find that any of these behaviors would render the display completely unusable.
1 happens on my TV capture card with a bt878 chipset. 2 happened on a video projector. 3 is seen very often. Had it on a 100Hz Doublescan-TV, many video projectors and TV capture cards. All these are very often caused by the lack of interlacing in the Apple ][s video output causing the decoder which actually counts the lines not to sync properly. This can sometimes be remedied by using a setting like "Old game" or "Still display". The only real fix would be to reprogram the video DSP...
Right. It's a shame that digital TVs have become so intolerant of distorted or non-standard signals. It's not really that hard to make the sync algorithm adaptive... I still remember the original RCA 630TS color receiver--it would sync solidly to a signal with such low signal-to-noise ratio that you could barely make it out in the "snow"! Of course, it had 30 tubes, too. ;-) "Analog emulation" would be a nice mode for digital TVs. ;-) -michael NadaPong: Network game demo for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."