Newsgroups: comp.sys.mac.misc
Path: utzoo!utgpu!watserv1!watcgl!imax!dave
From: dave@imax.com (Dave Martindale)
Subject: Re: Surely A Iifx Blows An Amiga 3
Message-ID: <1990Oct30.171538.14327@imax.com>
Organization: Imax Systems Corporation, Oakville Canada
References: <7876.271B9F29@fidogate.FIDONET.ORG> <1990Oct23.193646.8067@usenet.ins.cwru.edu>
Date: Tue, 30 Oct 90 17:15:38 GMT

In article <1990Oct23.193646.8067@usenet.ins.cwru.edu> pab@po.CWRU.Edu (Pete Babic) writes:
>
>Mac's have Interlaced video also. The video runs at 90Mhz so you don't notice
>the flicker, but its interlaced none the less. The 90Hhz video is one reason
>the Mac is hard to use for video, the Amiga video runs at standard NTSC rates.

Where did you get this information?  Any Mac video that I have ever looked
at was NOT interlaced.  The frame rate is typically somewhere around 70 Hz.

Do you have any actual measured numbers for any Mac video card - horizontal
and vertical frequency, or pixel clock.  Or data sheets that claim this?

It is not possible to provide "workstation" quality in screen images
while using NTSC-standard (actually EIA RS-170A) video timing.  Amiga chose
to use RS-170 timing, and so it fits in the low-cost video world very well.
The Mac family chose to be a workstation, with video suitable for that world.

As a result of these choices, the Amiga suffers from interlace flicker and the
Mac doesn't.  I have heard of a device called the FlickerFixer for the Amiga -
but if it eliminates flicker, it also eliminates NTSC compatibility.