Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rutgers!cbmvax!grr
From: grr@cbmvax.commodore.com (George Robbins)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: A3000 Memory
Message-ID: <11389@cbmvax.commodore.com>
Date: 6 May 90 07:15:33 GMT
References: <1990Apr26.003754.13905@mintaka.lcs.mit.edu> <11099@cbmvax.commodore.com> <1990Apr26.234239.25763@mintaka.lcs.mit.edu> <11171@cbmvax.commodore.com> <2970@ultb.isc.rit.edu> <11219@cbmvax.commodore.com> <45@bcstarc.UUCP>
Reply-To: grr@cbmvax (George Robbins)
Organization: Commodore, West Chester, PA
Lines: 34

In article <45@bcstarc.UUCP> root!bcstarc@nadia.UUCP (Frank Pecher) writes:
> In article <11219@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes:
> >In article <2970@ultb.isc.rit.edu> dcr3567@ultb.isc.rit.edu (D.C. Richardson ) writes:
> >
> >>since I'm here)  Will the 640x960 mode flicker?  If so, will it flicker
>                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> >Yes it will, and you probably need a multiscanning monitor of some kind to
>  ^^^^^^^^^^^
> 
> Now what??? I thought that only the "super" modes (1280 * XXX) would
> flicker? I was looking forward to a rock steady new Amiga display!
> Now would somebody please tell me which modes flicker and which do
> not?

In a sense, nothing has changed in that modes that require interlace, that
is two fields alternating at 30 Hz, will flicker.  The 31 KHz scan rates
supported by the ECS Agnus and Denise chips provide a way to do 640*400*4
(colors) without interlace, but the underlying mechinsims also let you muck
with a bunch of other modes, some of which may be interlaced.

The A3000 Display Enhancer can take any of the traditional Amiga displays
and de-interlace them, but does not handle the faster pixel rates implied
by the ECS 640*400*4 or 1280*X modes.

The two approaches are basically aimed a the same goal - providing a high-
resolution, non-flickering display.  ECS was inteneded as a basic chipset
capability, usable in any machine, the Display Enhancer is a value/cost
added adapter that happens to be built into the A3000.

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)