Question about VGA modes

Question about VGA modes

[Christian]

presotto@plan9.ATt.COM wrote:
: 640x480x8 is an extended mode.  The ones that are generic
: VGA are 640x480x{1,2,4}.

So can you define vgasize=640x480[1,2,4] in you plan9.ini file?

The reason I ask is because I define it 
monitor=vga
vgasize=640x480x1 or 8 

The problem I get is that the screen wraps.  I do not know why.  I have a 
Diamond SpeedStar PRO VLB and a GoldStar Standard VGA monitor. 

I look in all the vgadb definitions for the h-sync, v-sync, clock rate, 
and bandwidth and compared them to my xwindows configuration and it is all 
exact can anyone tell me why my monitor is wrapping?

In need of guidence.

Christian Pearce
pear6459@kutztown.edu
pearcec@enter.net
  

Question about VGA modes

[jmk]

you're right, you need to know how the banks are switched.
the notes i posted were extracted from an old example i had where i knew the
vga chip but not how to programme the clock.

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Subject: Question about VGA modes
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I have got the impression recently from a couple of postings
that the 640x480x8 mode is supported on alll VGA hardware - in other
words, that aux/vga doesn't need to know anything about the card
(other than the fact that it's VGA) to do 640x480x8.

I wonder if anyone can cofirm or deny this?  On reason that leads me
to doubt this is that said mode requires >64k of memory to run,
implying that bank switching is necessary - something that is card
dependent.

Any takers?

Martin Harriss
martin@mars.superlink.net

Question about VGA modes

[presotto]

640x480x8 is an extended mode.  The ones that are generic
VGA are 640x480x{1,2,4}.

------ original message follows ------

>From cse.psu.edu!9fans-outgoing-owner Sat Sep 16 15:20:26 EDT 1995
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Organization: SuperNet, Inc., NJ, USA (908-828-8988)
Subject: Question about VGA modes
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I have got the impression recently from a couple of postings
that the 640x480x8 mode is supported on alll VGA hardware - in other
words, that aux/vga doesn't need to know anything about the card
(other than the fact that it's VGA) to do 640x480x8.

I wonder if anyone can cofirm or deny this?  On reason that leads me
to doubt this is that said mode requires >64k of memory to run,
implying that bank switching is necessary - something that is card
dependent.

Any takers?

Martin Harriss
martin@mars.superlink.net

Question about VGA modes

[John]

>I have got the impression recently from a couple of postings
>that the 640x480x8 mode is supported on alll VGA hardware - in =
other
>words, that aux/vga doesn't need to know anything about the card
>(other than the fact that it's VGA) to do 640x480x8.

>I wonder if anyone can cofirm or deny this?  On reason that leads =
me
>to doubt this is that said mode requires >64k of memory to run,
>implying that bank switching is necessary - something that is =
card
>dependent.

Not true.  640x480x4 is the highest standard VGA resolution.

John Carmack
Id Software

Question about VGA modes

[martin]

I have got the impression recently from a couple of postings
that the 640x480x8 mode is supported on alll VGA hardware - in other
words, that aux/vga doesn't need to know anything about the card
(other than the fact that it's VGA) to do 640x480x8.

I wonder if anyone can cofirm or deny this?  On reason that leads me
to doubt this is that said mode requires >64k of memory to run,
implying that bank switching is necessary - something that is card
dependent.

Any takers?

Martin Harriss
martin@mars.superlink.net