Path: utzoo!utgpu!cunews!bnrgate!bwdls61!bwdls58!mlord
From: mlord@bwdls58.bnr.ca (Mark Lord)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Dual monitors
Message-ID: <5621@bwdls58.UUCP>
Date: 14 Feb 91 18:48:00 GMT
References: <26810@uflorida.cis.ufl.EDU> <91037.150254BUAD1621@Ryerson.CA> <26753@uflorida.cis.ufl.EDU> <166@cf_su20.cf_su10.Sbi.COM> <169@cf_su20.cf_su10.Sbi.COM> <2819@cod.NOSC.MIL>
Sender: mlord@bwdls58.UUCP
Reply-To: mlord@bwdls58.bnr.ca (Mark Lord)
Organization: Bell-Northern Research, Ottawa, Canada
Lines: 22

In article <2819@cod.NOSC.MIL> bmarsh@cod.nosc.mil.UUCP (William C. Marsh) writes:
<Sorry, the EGA/VGA interface is only 8 bits wide, so even if your VGA
<connects to the '16 bit' connector, the board itself can only do 8 bits
<at a time.  If you look at the memory architecture on the board, you will
<also notice that it is (256, 512, ot 1024) x 8 bits.  All the cards 'fake'
<16 bit accesses in graphics mode.

Utter rubbish!  The paradise vga card I have has memory that is 16 bits wide,
and it does indeed use 16-bit writes to update it (in text mode at the least).

<And anyway, all memory accesses to video memory is sync'd to H or V retrace
<time, so 16 vr. 8 bits really don't amount to much.  (Even in the VRAM 
<adapters too!  What a waste!)

I don't know that much about the VRAM things, but the whole idea of using
dual-ported VRAMs is to overcome the need to wait for retrace cycles before
writing, so this statement is probably as accurate as the first paragraph was.
-- 
 ___Mark S. Lord__________________________________________
| ..uunet!bnrgate!mlord%bmerh724 | Climb Free Or Die (NH) |
| MLORD@BNR.CA   Ottawa, Ontario | Personal views only.   |
|________________________________|________________________|