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From: alun@sunatb.UUCP (Alun Saunders)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Do you need 1M on video card for non-interlaced 1024x768
Message-ID: <393@sunatb.UUCP>
Date: 8 Apr 91 12:34:47 GMT
References: <nbeck.670969545@weber>
Organization: BSO/Automation Technology Breda B.V., The Netherlands
Lines: 29

nbeck@weber.ucsd.edu (Nathaniel Beck) writes:

>I am getting a 486 system. I want to be able to use 1024x768 (or
>whatever the correct numbers close to that are) on a non-interlaced
>monitor (a Seiko 1450, I think). One vendor has told me I need 1M on
>the video card to support non-interlaced SVGA, another has said that
>a much cheaper (ATI Wonder) card with only 512K will do. Which
>vendor is correct, or am I totally confused, or both?

>Thanks in advance

>Neal Beck

If you only want to use 16 colours then 512k is fine, only if you want
to do 1024x768x256 do you need the full 1 Meg.

You can quite easily confirm this by working out 1024*768=768k. For 16
colours you only need 4 bits per pixel, ergo you only need 384kbytes
video memory. For 256 colours you need 1 whole byte per pixel, i.e.
768kbytes.  The next round figures for these amounts are 512k and 1M
respectively.

BTW, the interlaced vs. non-interlaced issue has no effect whatsoever on
the amount of memory you need. Its only a question of timing on the
card.

Hope this is useful.

Alun Saunders