| From: | Colin Wenzel |
| Date: | 24 Jan 2000 at 03:40:41 |
| Subject: | Re: gfx cards - CV64/3D vs. Spectrum? |
From: Colin Wenzel <colstv@hotkey.net.au>
On 24-Jan-00, Brian Haug wrote:
-snip-
> (I'm assuming the monitor plugs directly into the video card's
> external slot.)
Yep... High density D15 socket.
> Talking about the _AMIGA_ boot-menu(i.e. selecting boot-drive): I
> guess one of the problems is that I don't understand this whole
> 'pass-through' thing..
OK here goes..... Before you run the Picasso / Cybergraphics
software your machine is basically a stock standard AGA machine
with video coming out of the normal RGB socket on the back.
The amiga does not support retargetable graphics natively, so,
to be able to use graphics cards, some software magic had to be done.
This is sort of like hijacking the ROM fuctions that are responsible
for all the graphical output to the AGA chip & hooking in new ones
that send the graphics to the gfx card instead of the AGA chip.
So, until you get the Gfx card software running to hijack the graphics
you only have stuff on the AGA RGB output.
The "Pass Through" is so that you can send the AGA gfx to the same
monitor BEFORE the gfx card software hijacks the ROM code &
patches itself in. Otherwise, if nothing is watching the AGA-RGB
output, you won't see anything until the gfx software kicks in.
If your startup sequence breaks, or you use the boot menu,
your gfx card software hasnt been run yet, so nothing is coming
out of the card.
That's why you need to "Pass Through" the AGA video.....
>Before my new 17" I had a Daewoo(sp?) 13" --
> the 13" 'displayed' this screen in a 'wrap-around' kind of fashion -
Thats because you were trying to display a scan speed your monitor
couldn't display.
> I could still make out and use the functions but it required some
> effort to decipher.
Seeing you have a Cyberstorm like me, there is an early boot
menu you can access by holding down the escape key after a
reboot (quickly after) it will give you the option to display
32Khz boot screens, that way, if you need the boot menu,
it will display in 32khz mode instead of 15Khz...
The Amiga defaults to 15Khz mode on startup, but if you have a
VGA - SVGA monitor connected, they cant sync below 29Khz.
So Phase5 put a (sort of) DBLPAL monitor driver in their
Cyberstorm EEPROM, that way it can change it's default speed
to 32 Khz so that your VGA monitor won't shit itself trying to display
15Khz startup screens.
EEPROM = Electrically-Erasable-Programmable-Read-Only-Memory.
>
> My new 17" displays this screen _normally_.
>
> If I got a gfx card without all this 'pass through-flicker fixer-scan
> doubler' "stuff", do they still treat the boot-menu screen as if it
> is just another screen??
Because you have a cyberstorm, you won't need the scan doubler
because of the (above) 32khz option..
>(i.e. if I got another monitor that didn't
> display this screen normally and just 'wraps' it around, would I
> still see it? I could live with the 'wraping' - but do gfx cards
> COMPLETELY block the boot-menu screen?)
It would diplay normally.
>
> (sigh) This is bringing up more questions than answers! ;)
>
> I'm now leaning toward the Spectrum again because of the 'boot-screen
> stuff', but would lean back toward the CV64/3D because of it's mem
> size...
>
Spectrum card has been ideal for me, (I got it for free too !!!)
I did have to make a pass through cable for it though.
If you didn't know about the early option screen on your Cyberstorm
I would also guess that you havn't done a EEPROM update on it either.
If you dont have the 31Khz options or something is missing,
you may need to update your Cyberstorm EEPROM first.
-------------------------------------
Colin Wenzel. Australia.
EMAIL: mailto:colstv@hotkey.net.au
URL: http://www.hotkey.net.au/~colstv/
ICQ: 17608330
'AMIGA' 4000T With CYIII-060, O.S 3.5
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