[comp.sys.amiga.hardware] A3000 Memory

daveh@cbmvax.commodore.com (Dave Haynie) (05/02/90)

In article <2970@ultb.isc.rit.edu> dcr3567@ultb.isc.rit.edu (D.C. Richardson ) writes:

>  Two quick questions: (I think I just answered the one myself, but
>since I'm here)  Will the 640x960 mode flicker?  If so, will it flicker
>on the A3000 through the VGA Port/De-Interlacer? 

Yes it will, and you probably need a multiscanning monitor of some kind to
display it.  The 640x960 mode is a 31kHz mode, so the on-board VDE device
gets out of its way automatically.  Which is good, because the VDE device
doesn't have enough memory for a 960 line display, and it only samples
70ns pixels, not 35ns pixels.

>Daniel C. Richardson


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	"I have been given the freedom to do as I see fit" -REM

jita@polaris.utu.fi (Marko Katajisto) (05/02/90)

[Dave writes...]
>Yes it will, and you probably need a multiscanning monitor of some kind to
>display it.  The 640x960 mode is a 31kHz mode, so the on-board VDE device
>gets out of its way automatically.  Which is good, because the VDE device
>doesn't have enough memory for a 960 line display, and it only samples
>70ns pixels, not 35ns pixels.

Too bad, I'd be glad to see a 1024*512 four colour display on my Nec 3D :(
How disturbing the interlace in 960 mode (1024 in PAL?) actually is? Is it
as bad as the flicker in 512 mode?

BTW: Can I use those 4MB (80ns ZIPs) I bought for my A2620 in A3000? They
don't support burst mode (I suppose) so how much faster would A3000 with
4 Megs of real SCRAM go?

Lots of thanks to you Dave and other people in A3000 team, really excellent
work I would say !!!

>-- 
>Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
>   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
>        "I have been given the freedom to do as I see fit" -REM

--
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    Internet: jita@utu.fi  Bitnet: jita@firien.bitnet  Tel: +358 21 325910
--
Jita  -  Marko Katajisto, TKO
-- 

barrett@jhunix.HCF.JHU.EDU (Dan Barrett) (05/03/90)

In article <JITA.90May2175745@polaris.utu.fi> jita@polaris.utu.fi (Marko Katajisto) writes:
>How disturbing the interlace in 960 mode (1024 in PAL?) actually is? Is it
>as bad as the flicker in 512 mode?

	No, it isn't.  It looks sort of like little ants "crawling" or water
"flowing" up the vertical lines.  There's little or no "shaking" or "jitter"
like the 400-line interlace you're used to.

	At least this was how Workbench 2.0 looked to me in super-hires
interlaced mode.

                                                        Dan

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

In article <JITA.90May2175745@polaris.utu.fi> jita@polaris.utu.fi (Marko Katajisto) writes:

>BTW: Can I use those 4MB (80ns ZIPs) I bought for my A2620 in A3000? 

Yup.

>They don't support burst mode (I suppose) so how much faster would A3000 
>with 4 Megs of real SCRAM go?

Guesstimates say that SCRAM memory goes about 20% faster in a 25MHz
machine.  It's possible future Coprocessor Slot or Zorro III DMA devices
will get even more of a boost from them.

>Jita  -  Marko Katajisto, TKO



-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	"I have been given the freedom to do as I see fit" -REM

LDSHANER@MTUS5.BITNET (Leon D. Shaner) (05/03/90)

I've not seen an answer to this yet:.

Given there is space on the mother board for ZIPs upto 4 or 16 MB depending
on the type of chip....

There is also space for an additional 1 MB of chip ram (meaning 2 total)...

What would happen if one was to just add the additional 8 chips in the CHIP
ram sockets???

On a stock machine this would mean you would have 2MB of CHIP installed as
well as the original 1 MB of Fast...would this fast memory be ignored??  Or
would the machine not know what to do??

In short would it mean you could have 2 MB of chip ram, & 5 or 17 MB of fast on
the mother board????

Please, someone who knows, clear this up.... Thanks...

--Leon

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root@bcstarc.UUCP (Frank Pecher) (05/04/90)

In article <11219@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes:
>In article <2970@ultb.isc.rit.edu> dcr3567@ultb.isc.rit.edu (D.C. Richardson ) writes:
>
>>since I'm here)  Will the 640x960 mode flicker?  If so, will it flicker
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>Yes it will, and you probably need a multiscanning monitor of some kind to
 ^^^^^^^^^^^

Now what??? I thought that only the "super" modes (1280 * XXX) would
flicker? I was looking forward to a rock steady new Amiga display!
Now would somebody please tell me which modes flicker and which do
not?

Thanks in advance.

    -- Frank

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grr@cbmvax.commodore.com (George Robbins) (05/06/90)

In article <45@bcstarc.UUCP> root!bcstarc@nadia.UUCP (Frank Pecher) writes:
> In article <11219@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes:
> >In article <2970@ultb.isc.rit.edu> dcr3567@ultb.isc.rit.edu (D.C. Richardson ) writes:
> >
> >>since I'm here)  Will the 640x960 mode flicker?  If so, will it flicker
>                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> >Yes it will, and you probably need a multiscanning monitor of some kind to
>  ^^^^^^^^^^^
> 
> Now what??? I thought that only the "super" modes (1280 * XXX) would
> flicker? I was looking forward to a rock steady new Amiga display!
> Now would somebody please tell me which modes flicker and which do
> not?

In a sense, nothing has changed in that modes that require interlace, that
is two fields alternating at 30 Hz, will flicker.  The 31 KHz scan rates
supported by the ECS Agnus and Denise chips provide a way to do 640*400*4
(colors) without interlace, but the underlying mechinsims also let you muck
with a bunch of other modes, some of which may be interlaced.

The A3000 Display Enhancer can take any of the traditional Amiga displays
and de-interlace them, but does not handle the faster pixel rates implied
by the ECS 640*400*4 or 1280*X modes.

The two approaches are basically aimed a the same goal - providing a high-
resolution, non-flickering display.  ECS was inteneded as a basic chipset
capability, usable in any machine, the Display Enhancer is a value/cost
added adapter that happens to be built into the A3000.

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)