[comp.sys.amiga.hardware] Still more A3000 questions...

hood@cbmvax.commodore.com (Scott Hood) (05/02/90)

In article <1990May1.213054.16935@ux1.cso.uiuc.edu> menelli@cs.uiuc.edu (Ron Menelli) writes:
>Despite all of the wonderful A3000 information floating around thanks to
>Dave Haynie and the rest of the crew, I still have managed to come up with
>a few questions no one has covered yet...
>
>1). I have a pretty good idea about what kind of output the de-interlacer
>    gives for each graphics mode, but I'm a little unclear on the PAL
>    resolutions. Any A3000 can do PAL mode, right? I believe I've seen
>    software that switches between the modes (PALBoot ?), so I'm assuming
>    that is how you can get to these modes. The real question is, is the
>    de-interlacer output for PAL mode still at 31.5 KHz, or is it something
>    else? And if it is 31.5 KHz, how does it handle the extra vertical
>    resolution? By using overscan?

Any A3000 can output PAL video modes, so that the display enhancer can
either de-interlace or scan-double the output to produce a 31.25Khz
horizontal scan rate and a 50Hz vertical rate.  Any multiscan monitor
can handle this if it is even close to being VGA compatible.  To access
the PAL video modes the user will open the `monitor' drawer and click on
the PAL monitor icon.  Then in the `prefs' drawer the user can run
`wbscreen' and select the default screen modes or the now present PAL
video modes.  The NTSC video modes are 15.734Khz (31.46Khz
de-interlaced) horizontal and 60Hz vertical FYI. 


Scott

>
>2). I plan on getting a NEC MultiSync 3D monitor (regardless of whether the
>    PAL resolutions require it) for future compatibility reasons (can you
>    say ULowell?) Does anyone have any experience with this monitor or just
>    happen to know if it would work correctly? The problems I could forsee
>    are: Weird cable needed (ala DiamondScan), interlace not supported (for
>    1280x400 and 640x960 modes), anything else I've missed(?)
>
>Thanks in advance for any help,
>Ron "I want my A3000 NOW!!!" Menelli
>menelli@cs.uiuc.edu

daveh@cbmvax.commodore.com (Dave Haynie) (05/03/90)

In article <1990May1.213054.16935@ux1.cso.uiuc.edu> menelli@cs.uiuc.edu (Ron Menelli) writes:

>1). I have a pretty good idea about what kind of output the de-interlacer
>    gives for each graphics mode, but I'm a little unclear on the PAL
>    resolutions. Any A3000 can do PAL mode, right? I believe I've seen
>    software that switches between the modes (PALBoot ?), so I'm assuming
>    that is how you can get to these modes. 

Same basic mechanism, though of course supported in 2.0 via a preferences editor.
An NTSC machine in PAL mode will be 1% off, as will a PAL machine in NTSC mode.
Only an issue if you're genlocking.

>    The real question is, is the de-interlacer output for PAL mode still at 
>    31.5 KHz, or is it something else? 

It is still at 31.5KHz

>    And if it is 31.5 KHz, how does it handle the extra vertical resolution? By using 
>    overscan?

The same way PAL uses the basically same horizontal frequency as NTSC and still gets
the extra lines -- by increasing the vertical display time.  So NTSC gives you 60Hz
vertical refresh, PAL gives you 50Hz.  

>2). I plan on getting a NEC MultiSync 3D monitor (regardless of whether the
>    PAL resolutions require it) for future compatibility reasons (can you
>    say ULowell?) 

We've used a number of NECs here, and never had a problem to my knowledge.  I
think they're among the best.

>    interlace not supported (for 1280x400 and 640x960 modes)

I'm not sure if anyone's tried those modes with the NECs.  I'm still using a Moniterm,
or I probably would have tried those out myself.  

>Thanks in advance for any help,
>Ron "I want my A3000 NOW!!!" Menelli
>menelli@cs.uiuc.edu


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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	"I have been given the freedom to do as I see fit" -REM