Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wasatch!cs.utexas.edu!uunet!mcvax!cernvax!ethz!visinfo
From: visinfo@ethz.UUCP (VISINFO Moderators)
Newsgroups: comp.sys.amiga
Subject: Re: 60 Hz on PAL (50 Hz) Amigas
Keywords: 50Hz 60Hz NTSC PAL
Message-ID: <1494@ethz.UUCP>
Date: 5 Jul 89 13:29:37 GMT
References: <3303@shlump.dec.com>
Organization: ETH Zuerich, Switzerland
Lines: 41

In article <3303@shlump.dec.com> athomson@ayov10.dec.com (Alan Thomson) writes:
>In article <1427@ethz.UUCP>, visinfo@ethz.UUCP (VISINFO Moderators) writes...
>
>>60Hz emulation on PAL Amigas
>>****************************
>
>>Yes, it's true, you CAN produce 60Hz on "normal" PAL Amigas.
>>And moreover, you can have almost all the advantages of 60Hz on your PAL
>>(50Hz) Amiga: less flickering in noninterlaced mode, and an almost
>>acceptable picture in interlaced mode.

>HOW ?? Tell me more, where do I send my money ?? who do I have to kill ?? 
>I would give a lot to have 60Hz (30Hz) flicker in interlace rather than
>the 50Hz (25Hz) I have now.

I plan to release the 60Hz Emulator as one module in a resident utility
I am working at presently. This way you can switch 50/60 at ANY time
and the status survives reboot. However, the PowerUtility is not yet
finished entirely. Also, I have not yet found a convenient way to distribute
it. Hope you can get it before the end of '89... or earlier!

>A question though.. In 60Hz mode, how close can you get back to the PAL
>screen size ? (Using morerows or whatever)

Physically, you have 313 screen lines in 50Hz mode and 261 in 60Hz.
The standard screen size as used by AmigaDOS is 256 lines for 50Hz
and 200 lines for 60Hz. The maximum number of usable vertical lines incl.
overscan is about 280 in 50Hz and 230 in 60Hz. Therefore it is impossible
to get the original PAL screen size in 60Hz. However, you can MIX PAL and NTSC
screens the following way: You boot up with 50Hz and get a PAL Workbench,
you load all utilities you want to bring up PAL screens, switch to 60
and continue work. This way, you really have all the advantages of both
modes.

F. Buergel

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