Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!rochester!cornell!uw-beaver!tektronix!tekcrl!tekfdi!videovax!stever From: stever@videovax.Tek.COM (Steven E. Rice, P.E.) Newsgroups: comp.sys.amiga Subject: Re: Possible new hack Message-ID: <4494@videovax.Tek.COM> Date: Wed, 15-Jul-87 11:10:38 EDT Article-I.D.: videovax.4494 Posted: Wed Jul 15 11:10:38 1987 Date-Received: Sat, 18-Jul-87 04:03:50 EDT References: <1699@amiga.amiga.UUCP> Reply-To: stever@videovax.Tek.COM (Steven E. Rice, P.E.) Distribution: na Organization: Tektronix Television Systems, Beaverton, Oregon Lines: 36 In article <1699@amiga.amiga.UUCP>, Dale Luck (dale@amiga.UUCP) writes: > For you guys that need 120 hz refresh but can get by with half the number > of lines are your display, you could try this. > I haven't tried this out , but it shoudl work. > Write the beam counter in the middle of the display to bump it down > to the end. I don't remember if the copper can write the beam counter, > the chip designers might have gone crazy again with their arbitrary > limitations. But anyway, write it so it is about 255 or so, it will then > continue counting up to 262 or so and trigger vblank and the display > will start again. Most monitors should not have any trouble with this. > Well, I'm no hardware guy so that is just a guess to. No luck, Dale! Most monitors will ignore a vertical interval in the middle of the active picture area. Those that don't will have a fit trying to synchronize to something that is twice normal rate. (The deflection magnetics are usually resonated at the scan rate to reduce drive power requirements.) > This response prompted by some guy in toronto wanting to quad lace > the display. I remember the tektronics stereo displays were running at ^^^^^^^^^^ Aaaaaarrrrggggggghhhhhh!!!!! That's TEKTRONIX!!! No "c"s. No "s"s. > twice refresh rate so this idea just popped up. Meaning they were > interlacing at 120 instead of 60hz per field. Special monitors. Big bucks. Not interlaced -- progressive scan (how progressive!). Since the liquid crystal light valve can switch polarization between frames, every other frame is a "left eye" frame. Steve Rice ----------------------------------------------------------------------------- new: stever@videovax.tv.Tek.com old: {decvax | hplabs | ihnp4 | uw-beaver | cae780}!tektronix!videovax!stever