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Article View: comp.sys.amiga.tech
Article #9397

Re: WaitTOF in interlace mode

#9397
From: Dale Luck
Date: Wed, 27 Jul 1988 22:00
41 lines
2299 bytes
In article <6639@well.UUCP> ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) writes:
>
>	An inspection of GfxBase structures reveals a lot of intersting and
>promising locations for inspection.  However, since they're undocumented (no
>comments describing what they do), they are most likely private, subject to
>change, don't even think about it, etc etc etc.

You're right if you expect to see 1.5 come out with some more bug's fixed
and even greater features, you keep your dirty hands off my dirty bits.
;-)

How about if WaitTOF returns a number describing the field we are on.
There are actually 4 distinct fields in the generation of ntsc video.
Current hardware only allows easy extraction of the LONGFRAME/SHORTFRAME
information.

> So we are left with a hardware solution.

In general this is a poor assumption.
The hardware guys need a bit of freedom to exercise their abilities
to fix problems and improve the system. There may be times when you will
just have to wait for us to provide a clean and future compatible way
at getting at this information via well thought out software mechanisms..

>
>	The hardware solution is to look at custom.vposr and examine bit #15.
>If it is set, you are in the long field (whatever that means).  If it is
>unset, you are in the short field.  It is unclear which is the even field
>and which is the odd field.  Dale?

The information is in the hardware manual. If bit15 is set then we are
on the Long Frame.

>_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
>Leo L. Schwab -- The Guy in The Cape	INET: well!ewhac@ucbvax.Berkeley.EDU

-- 
Dale Luck     Boing, Inc. {cbmvax|oliveb|pyramid}|!amiga!boing!dale
Although I do contract work for Amiga-LosGatos, my opinions probably
don't represent those of Commodore or its management or its engineers,
but I think the world would be a better place if they did.
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!husc6!think!ames!oliveb!amiga!boing!dale
References: <4860@killer.DALLAS.TX.US> <6639@well.UUCP>

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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!husc6!think!ames!oliveb!amiga!boing!dale
From: dale@boing.UUCP (Dale Luck)
Newsgroups: comp.sys.amiga.tech
Subject: Re: WaitTOF in interlace mode
Message-ID: <343@boing.UUCP>
Date: 27 Jul 88 22:00:06 GMT
References: <4860@killer.DALLAS.TX.US> <6639@well.UUCP>
Reply-To: dale@boing.UUCP (Dale Luck)
Organization: Boing, Milpitas, Ca.
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