Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!cbmvax!daveh From: daveh@cbmvax.cbm.UUCP (Dave Haynie) Newsgroups: net.micro.amiga Subject: Re: Memory && Disks && Flicker Message-ID: <934@cbmvax.cbmvax.cbm.UUCP> Date: Tue, 28-Oct-86 11:41:08 EST Article-I.D.: cbmvax.934 Posted: Tue Oct 28 11:41:08 1986 Date-Received: Tue, 28-Oct-86 21:34:39 EST References: <2834@garfield.UUCP> Organization: Commodore Technology, West Chester, PA Lines: 68 > Keywords: *subject_line > > - now I know why blue was always my favourite colour. Blue disks work. > Tan-coloured ones don't. This does appear to be true; I've had lots of success with blue disks, only a few have gone bad. I tried very light tan disks once; never again! Black disks seem almost as good as blue :-). > - why are there 2 Amiga monitors? The one in front of me is a 1080, with > the brightness, etc controls written in black on the little door on the > front. The screen is much more glare-prone, flicker-prone, and colour- > not-as-good prone than the other monitors, also 1080, with the controls > labelled with raised words the same colour as the rest of the case (the > same colour as those tan disks!). They're probably from different vendors. Commodore OEM's the monitors. If the newer one is the better one, its called an improvement (if not, its called a cost reduction). > - even so, I frequently work in hi-res, without going blind yet. I change > the "white" in hi-res to a medium grey, and the title bars stop flickering. > If I need to use white, I make a different colour white; same with black. > According to a rumour (and Lord knows there are enough of those, with > precious little in the way of official announcements) the first 2 colours > on the palette (called the "clear colours" by the rumourer) are not > well liked by the Amiga's video chip, which results in their being more > flickery than the others. Nope. The video chip itself (Denise) puts out 4 bits of digital info for each of R, G, and B. The D-A conversion is done with a precision resistor network. The chip doesn't see any difference between a white and a grey. It most likely your eye. In interlaced mode, the perceived flicker is based of the apparent persistance of the image. This is a combination of how long the image actually remains on the screen, and how long the image is retained after that by your eye. The eye will retain a low brightness image longer than a high brightness image, that's why grey flickers less. Also, you'll see less border flicker between similar colors than between contrasting colors. If you really want some flicker, fill and interlaced screen with something like alternating lines of black and white. Also, in rectangular images, you get lots of boundary flicker, since you have large boundaries along two neighboring scan lines. A natural image, like what you see on TV, breaks boundaries up along several neighboring scan lines, so you wouldn't see as much, or even any flicker (compare Dave W.'s HAM images to a CLI or terminal in interlaced mode). This isn't a fault of the Amiga video per se, other than the fact that its a fault of the NTSC standard and the Amiga was designed to be compatible with this standard. > Disclaimer: Only I know what I'm talking about, and sometimes not I always > though don't. > > Interesting thing to do: Naw, that's enough for now, I'll put it in next time. > > John Russell > UUCP: {akgua,allegra,cbosgd,ihnp4,utcsri}!garfield!john13 > CDNNET: john13@garfield.mun.cdn -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dave Haynie {caip,ihnp4,allegra,seismo}!cbmvax!daveh "Laws to supress tend to strengthen what they would prohibit. This is the fine point on which all the legal professions of history have based their job security." -Bene Gesserit Coda These opinions are my own, though for a small fee they may be yours too. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~