Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!ames!ucbcad!ucbvax!decvax!decwrl!pompeo.dec.com!zabot From: zabot@pompeo.dec.com (Adv.Tech.Mgr-ACT Torino) Newsgroups: comp.sys.amiga Subject: PAL and flickering (NTSC programs on PAL Monitor) Message-ID: <7482@decwrl.DEC.COM> Date: Mon, 12-Jan-87 04:40:51 EST Article-I.D.: decwrl.7482 Posted: Mon Jan 12 04:40:51 1987 Date-Received: Mon, 12-Jan-87 18:48:09 EST Sender: daemon@decwrl.DEC.COM Organization: Digital Equipment Corporation Lines: 39 Randy (Spencer) writes: | PPS, what does an NTSC Amiga program look like on the PAL monitor? Does it | only display in the bottom 200 lines of the monitor when opening a screen? | Do they have the spaces between the lines when not in interlace mode, Do they | have an interlace mode? No, they wouldn't. So they just duplicate every | line twice when in (fake non interlace mode) But boy they must have flicker | *all* the time! First: relax ! We do NOT have flickering all the time, so if you plan to relocate to europe you can still enjoy an AMIGA !! NTSC-PAL problem. Professional. Most professional terminals and PC (DEC-IBM-..) are using some sort of NTSC standard also in Europe. Home computer (ALL of them) are using PAL standard. So even a C64 has the same problem. The result is very simple. The apparence is that we have a smaller usable area on the video screen and a different ratio ( vert size vs oriz. size). This means that a CIRCLE in NTSC is an oval in PAL.This is due to the higher number of lines (625) on the same phisical space ( screen size) compared to the NTSC (525 ??). The differnt ratio creates a lot of problem with many traditional computer and programs ( think of a CAD program :-) drawing a circle !!). This is not the case with many programs on the Amiga 'cause they use the intuition interface, so you can resize the window and the ratio as well. One think that is difficult to understand is the relation of the 200/400 lines with the 525 in NTSC. I never counted the border lines, are they 125 ? Let's now consider Amiga. 1.1 is the same old story. ( smaller screen area). With 1.2 PAL has an extra area usable, for a total of 256 lines ( or 512 in interlace mode). That's a figure I like more ( a power of two has always the right to appear in a computer ! :-). And we can really use that area which is visible via Intuition. This means ,most of the time, that you can drag any window in this area, but very seldom we can enlarge your window to include this bottom area. This depend only on the way your program was written. To make a long story short. A good sighted guy can have as many as 51 lines on his terminal emulator. Or better , anyone can have a regular 25 lines terminal emulator PLUS an extra window ( 6-7 lines long ). Flickering. In Europe the monitors are totally different from the US ones. I think C= is using Philips monitors. The final result is that, even if these monitors seam to be a better quality that the NTSC ones, we have the same level of flickering under the same conditions. marco