blgardne@esunix.UUCP (Blaine Gardner) (01/30/88)
I just got a NEC Multisync monitor for my Amiga this week. It looks
good, but has one big problem: it doesn't display interlace correctly.
Instead of displaying the two frames offset by one scanline, it places
both frames on the same set of scanlines. I get the full flicker effect
of interlace, but since there are two different sets of data being
displayed on each line, text and any detail smaller than 2 scan lines is
unreadable.
I'm using analog RGB, and composite sync. Do I need to use seperate
syncs, or is there an internal adjustment to make interlace display
correctly?
I'm also unhappy with the convergence, so I need to get the tech docs on
this monitor, any suggestions?
--
Blaine Gardner @ Evans & Sutherland 540 Arapeen Drive, SLC, Utah 84108
UUCP Addresses: {ihnp4,ucbvax,allegra,decvax}!decwrl!esunix!blgardne
ihnp4!utah-cs!esunix!blgardne usna!esunix!blgardne
"Nobody will ever need more than 64K." "Nobody needs multitasking on a PC."page@swan.ulowell.edu (Bob Page) (02/02/88)
blgardne@esunix.UUCP (Blaine Gardner) wrote: >NEC Multisync monitor ... doesn't display interlace correctly. Most of the multiscan/sync type monitors have problems with interlace. In fact, I think either NEC's or Sony's even says so. >any suggestions? Get a FlickerFixer, now known as an AGA2000 from MicroWay. The resulting display is *fabulous*. You'll never want to go back. ..Bob (who doesn't have one!) -- Bob Page, U of Lowell CS Dept. page@swan.ulowell.edu ulowell!page "I don't know such stuff. I just do eyes." -- from 'Blade Runner'
cmcmanis%pepper@Sun.COM (Chuck McManis) (02/02/88)
blgardne@esunix.UUCP (Blaine Gardner) wrote: > NEC Multisync monitor ... doesn't display interlace correctly. Then, in article <2582@swan.ulowell.edu> (Bob Page) writes: > Most of the multiscan/sync type monitors have problems with interlace. > In fact, I think either NEC's or Sony's even says so. Putting on my video hat for the moment, when you think about this for a moment the problem becomes self evident. (Well, it did to me, and it might to you too if you have read the Amiga Video tutorial :-)) The answer goes something like this : Monitors originally had fixed horizontal scanning frequencies, television sets used 15,750 Hertz. What the Horizontal sync pulse does is tell the monitor electronics that ``now'' is the time to start a new trace across the front of the tube. Since the beam is moving down at the same time that it is moving sideways, where the hsync pulse occurs determines where, relative to the top of the screen or previous line, the new line will appear on the screen. When the horizontal sync pulses are evenly spaced you get an even distance between lines. Those wizards that brought you Tv though, thought up an even wilder scheme. They said "Gee if on the odd frames we make the first horizontal sync pulse half as wide, then the lines from the odd frames will appear *between* the lines of the even frames." And poof interlace was born. And it was so, and this worked because the beam always traced across the screen at the same frequency. Now, enter 'MultiSync' monitors. These monitors *vary* their own horizontal frequency to match that of the computer. Very whizzy indeed but what does that mean ? It means that there is a phase-locked loop on the Hsync input. And that means that when the monitor sees this little glitch in the horizontal sync pulse, which would start an interlaced frame, it *tracks* it. Yes, that's right, it adjusts it self to get 'back in sync' with the computer. And when it does, by the next two scan lines maximum, it has the display all lined up nicely again and is probably feeling extremely proud of itself. And that means your interlace pictures will probably look really weird on a good multisync. But of course, the FlickerFixer does indeed fix this and that's the end of the problem. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you.
rsb584@leah.Albany.Edu (Raymond S Brand) (02/03/88)
My Mitsubishi DiamondScan (AUM-1371A) works real nicely on my 1000 in interlace mode. RSXB
cs178abu@sdcc8.ucsd.EDU (John Schultz) (02/04/88)
My multisync II doesn't seem to have any problems with interlace. I have run Prowrite and Digipaint; they look great. I made my own cable and it's hooked up to a 2000. What's the deal? The only time it hosed up was when the cable was wrong... John
blgardne@esunix.UUCP (Blaine Gardner) (02/05/88)
in article <2582@swan.ulowell.edu>, page@swan.ulowell.edu (Bob Page) says: > blgardne@esunix.UUCP (Blaine Gardner) wrote: >>NEC Multisync monitor ... doesn't display interlace correctly. > > Most of the multiscan/sync type monitors have problems with interlace. > In fact, I think either NEC's or Sony's even says so. > >>any suggestions? > > Get a FlickerFixer, now known as an AGA2000 from MicroWay. The resulting > display is *fabulous*. You'll never want to go back. Yes, I'm planning to. The Flicker Fixer, and other de-interlacers that are supposed to be coming RSN, are the big reason that I got the Multisync. (The fact that I only paid $225 was also a big reason!) But until the price on the Flicker Fixer comes down considerably from $600, or my computer fund makes a drastic jump, I'll be without a Flicker Fixer. (Why $600? At $200, I'd buy it. At $300, I'd think about it, then buy it. At $600, well... I guess flicker isn't all THAT bad.) But until the day I get a Flicker Fixer, isn't there ANYTHING I can do to get interlace to work right (besides put the NEC back in the box, and use the old 1080 again)? -- Blaine Gardner @ Evans & Sutherland 540 Arapeen Drive, SLC, Utah 84108 UUCP Addresses: {ihnp4,ucbvax,allegra,decvax}!decwrl!esunix!blgardne ihnp4!utah-cs!esunix!blgardne usna!esunix!blgardne "Nobody will ever need more than 64K." "Nobody needs multitasking on a PC."
king@dciem.UUCP (Stephen King) (02/08/88)
In article <40648@sun.uucp> cmcmanis@sun.UUCP (Chuck McManis) writes: > ... an even wilder scheme. They said "Gee if on the odd frames we make the >first horizontal sync pulse half as wide, then the lines from the odd frames >will appear *between* the lines of the even frames." ... Not exactly. Horizontal sync pulses are ALWAYS the same width. What changes is the relationship between H & V sync. NTSC requires 262.5 horizontal lines per field (525 lines per frame). This means that, during display of field 0, V sync starts in the middle of the last line. Consequently, for display of field 1, V sync ends halfway through the first line and starts up again at the end of the last line. Voila - INTERLACE (no poofs here :-) ...sjk -- * Defence & Civil Institute * {decvax|ihnp4|watmath}!utzoo!dciem!king * of Environmental Medicine * or uwbeaver!utcsri!dciem!king - Simulation & Training Group - or uunet!mnetor!dciem!king (may or may not endorse my opinions) or dciem!king@zorac.arpa
blgardne@esunix.UUCP (Blaine Gardner) (02/09/88)
in article <782@sdcc8.ucsd.EDU>, cs178abu@sdcc8.ucsd.EDU (John Schultz) says: > My multisync II doesn't seem to have any problems with interlace. > I have run Prowrite and Digipaint; they look great. I made my own > cable and it's hooked up to a 2000. What's the deal? The only time > it hosed up was when the cable was wrong... Could you tell me what pins your cable is using? I'm running the analog RGB and composite sync lines, are you using Composite or seperate syncs? Perhaps something need tweaking inside the Multisync, or maybe there is some difference between your Multisync II, and my original Multisync. The 1080 really looks poor now that I've used the Multisync for a couple of weeks, I'd hate to have to go back to it. -- Blaine Gardner @ Evans & Sutherland 540 Arapeen Drive, SLC, Utah 84108 UUCP Addresses: {ihnp4,ucbvax,allegra,decvax}!decwrl!esunix!blgardne ihnp4!utah-cs!esunix!blgardne usna!esunix!blgardne "Nobody will ever need more than 64K." "Nobody needs multitasking on a PC."