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From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: Quetsions about the 3000...
Message-ID: <14916@cbmvax.commodore.com>
Date: 5 Oct 90 20:27:50 GMT
References: <90276.132159IO91461@MAINE.BITNET>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 51

In article <90276.132159IO91461@MAINE.BITNET> IO91461@MAINE.BITNET (Tom Nezwek) writes:

>          I have a few questions that maybe some 3000 owner
>     could answer...

How about a 3000 designer (although I had little to do with the areas in
question...).

>          1. Does the amber chip fill in the missing scanlines
>             when in non-interlace mode like the flicker fixer
>             does?  IE: are there missing scanlines in 300 x 200 mode?

Amber is clever enough to do scanline doubling for any non-interlaced mode.
What this means is that a single 15kHz scan line is buffered and then sent
out as two 31kHz lines.  So you don't see the black line bands as with normal
NTSC type display, and there's no full screen buffering as with Amber's
de-interlacing modes, so you don't get any slowdown effects -- everything
still acts as a 50 or 60Hz mode should.

>          2. Is the built in SCSI controller basically a 2091?

It is essentially a high speed, 32 bit A2091.  The A3000 disk software is an 
update of the A2091 stuff.

>             If I bought a 3000, I would want to be able to put at least
>             2 Quantum 105s in one.  

Two would fit inside; you'll need an external box for more of them.

>             If the built in controller is like the 2091 then I would have 
>             problems transfering files from one hd to the other without 
>             crashing...  This is a well known bug in the 2091 controller and 
>             has been discussed recently..

Well, this problem actually has nothing to do with the 2091 per se, it's a 
bug in the Western Digital SCSI chip used for both 2091 and A3000.  The last
revision of the SCSI chip had bugs that broke reselect capability at the high
level of software, so the A2091 and A3000 SCSI drivers solved the problem using
low level commands.  The new release of the chip fixed the high level commands
but broke the low level commands.  So, in multi-drive 2091 or 3000 setups 
using this chip, it is best to say "no" to the "supports reselect" option in
HDToolBox, and everything is cool.  A new device driver will apparently fix
this, going to the fixed high level commands in the new chip.

>                            -Tom Nezwek


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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	Standing on the shoulders of giants leaves me cold	-REM