From: 22black@sol.cs.wmich.edu (Martin E. Black)
Subject: Re: A4000+DOMINO !!!
Keywords: A4000, DOMINO GFX BOARD
Organization: Western Michigan Univ. Comp. Sci. Dept.
Date: Thu, 1 Oct 1992 04:08:48 GMT

barrett@iastate.edu (Marc N Barrett) writes:

>In article <1992Sep30.164858@cc4.kuleuven.ac.be> stud11@cc4.kuleuven.ac.be (Lode Vande Sande) writes:
>>

>>
>>        If  I'm  correct, the performance of the AA chip set depends on the
>>type  of ram chips you use for your CHIP ram.  Is this true ?  If so, could
>>anyone  please  tell  me exactly what this means and with what kind of CHIP
>>ram the A4000 comes with out the box ?

>   The A4000 comes with 2M of chip RAM, which is the most that the Alice
>chip (replacement for Agnus) can address.  I assume that Commodore is using
>the types of RAM chips that optimize the performance of the Amiga graphics
>system.

Wrong different ram chips


>>        The  A4000's display can range upto 1280x512 (maybe higher, I don't
>>know), but the question is :  is this interlaced ?  

>   Yes, the 1280x512 mode is interlaced.  Even worse, it is interlaced with
>a field rate of 25Hz.  

Completely wrong there.  1280x512 is de-interlaced at 30khz and the scan 
rate is at a pal 50hz.  Nice rock steady display.

>>I have read that the AA
>>chip  set  can  produce  non-interlaced displays, but can it do this in all
>>these  resolutions  ?  

>   No.

True, but only for 640x960 and 800x600.  All else de-interlace in the chip
itself as opposed to de-interlacing outside [ as with a3000] 
And lets not forget a full 8bitplane for all display modes along with 
Ham8 for all modes.


>   The A4000 offers exactly the same non-interlaced modes as the A3000 with
>the Display Enhancer turned on.  The Display Enhancer has effectively been
>moved internally to the Lisa chip, but the non-interlaced modes offered are
>exactly the same.  The highest non-interlaced resolutions offered by the 
>A4000 are 720x480 60Hz NTSC and 720x560 50Hz PAL.  No higher non-interlaced
>resolutions are possible.

As i said all except for those modes requiring higher freq than 31khz which is 
what i said above 62 and 50 respectively

>   In addition, you may have heard about an 800x600 mode, but this mode is
>interlaced at 72Hz (field rate of 36Hz), and has a horizontal frequency of
>24.62Khz.  It is not usable on any VGA monitors, and few multisync monitors
>will support it.  Even if you do find a monitor that supports the rather low
>frequency of 24.62Khz, the monitor must also support interlacing.  And even
>if you do find a monitor that supports the 24.62Khz frequency and interlacing,
>the display will not be nearly as sharp as a VGA 800x600 non-interlaced 
>display.  I would ignore the 800x600 mode if I were you.

First of all the C= 1960 and 1950 works fine in all modes, and could be had
for $400.  



>>  This
>>would  mean  that they would use 62KHz if I'm not mistaken ...  Let's see :
>>normal 640x200 -> 15KHz, productivity 640x480 (non-interlaced) -> 31KHz, so
>>if  the  640x960  would  be  without flicker, it would have to have a 62KHz
>>frequency,  isn't it ...  Again can anyone explain this to me/correct me on
>>this ...


>>	I've  seen  some  postings here that Commodore would be putting in
>>on-board  SCSI,  a  DSP  and  16-bit  sound  by X-mas.  Ok, I know this is
>>advocacy,  but I really would like to get something for my money, so could
>>someone  please  tell me if this has been confirmed or at least heard from
>>several independant sources ?

>   I will believe it when I see it.  I am not expecting Commodore to be 
>bringing out any new systems with SCSI or DSPs as standard hardware within the
>next six months.  Commodore may bring out a Zorro II/III SCSI II card and a
>Zorro II/III card with a DSP, but since the hardware is not standard with
>the systems, the software support will suffer.  

>>        And  as a last question :  will there be an A4000 Tower ?  Does the
>>A4000 have enough free space to install a Syquest ?  (They told me that the
>>A3000 didn't).

>   I've heard rumors of an A4000T, but they were just rumors.

>>+----------------+-------------------+------------------------------------+
>>|/////\\_____\\\\|                   |                                    |
>>|//// /_____ \\\\|  Kurt Haenen      |  Tjee, with this new cruncher,     |
>>|/// /\____//\\\\|  Homsemstraat 53  |  I can put two times as many disks |
>>|\\\/\ \   / / \\|  3891 Borlo       |  in one box than I used to ...     |
>>|\\\/\\ \ / /\/\\|___________________|____________________________________|
>>|\\\/\\\/_\/\/ //|                                       |                |
>>| Kurt \/_\ / ///|  EMAIL : STUDxx @ CC4.KULEUVEN.AC.BE  | 2B || !2B T^ = |
>>| Haenen  \\\/// |                                       | THE QUESTION ! |
>>+----------------+---------------------------------------+----------------+

>---
>| Marc Barrett -MB-  |  email: barrett@iastate.edu
>-----------------------------------------------------------------------
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