AGNUS despute:8370vs8372a
Brian Middlebro'
Opionions needed!!!
I recently ordered a '1 Meg agnus' over the internet.
When I received it, it was an 8370. I emailed the guy back and he said
that it will work just as well as any 8372a,8375 AGNUS... And that all that
was needed was the mother board modification, and it will address 1MEG...
So can anyone help me convince this guy that he is wrong? (8370=1meg agnus)
MicroTech
On 17-Jul-96 15:45:53, Brian Middlebro' (b...@vcn.bc.ca) posted:
> Opionions needed!!!
An 8370 is a 512K Agnus chip - period. No amount of modifications will
change that. 8372 and 8375 are the 1MB Agnus part numbers.
John Crookshank
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K. C. Lee
MicroTech (jo...@mt-inc.com) writes:
> An 8370 is a 512K Agnus chip - period. No amount of modifications will
> change that. 8372 and 8375 are the 1MB Agnus part numbers.
8372A is a 1 meg Agnus while 8237B and 8375 are a 2 meg Agnus part. The
8370 is just the plain old 512K Agnus as in the A1000 in a different
package and added circuits.
> John Crookshank
K. C. Lee
MicroTech
On 20-Jul-96 17:39:25, K. C. Lee (de...@FreeNet.Carleton.CA) posted:
No, the A1000 Agnus is an 8361. It is a DIP chip, and cannot be used with
any other Amiga models. 8370 is the A500/A2000 512k Agnus part. 8372A is a
1MB NTSC Agnus, and 8372B is the 2MB NTSC Agnus.
As far as the 8375 goes, it depends on the chip revision whether it is 1MB
or 2MB, and NTSC or PAL.
Rev 10 & 11 are 2MB chips, PAL/NTSC, respectively.
Rev 16 & 17 are 1MB chips, PAL/NTSC, respectively.
Regards,
Bruce Abbott
>Opionions needed!!!
>I recently ordered a '1 Meg agnus' over the internet.
>When I received it, it was an 8370. I emailed the guy back and he said
>that it will work just as well as any 8372a,8375 AGNUS... And that all that
>was needed was the mother board modification, and it will address 1MEG...
>So can anyone help me convince this guy that he is wrong? (8370=1meg agnus)
He's right about it being a 1 Meg Agnus (also called a 'fat' Agnus). It can
address 512K chip and 512K fast RAM, for a total of 1MB.
However, it will NOT work 'just as well as any 8372a...'. In particular:-
1/ It cannot address 1MB chip RAM.
2/ It doesn't support large blits.
3/ It cannot be switched to PAL mode.
4/ It does not support ECS screen modes.
The 8372a is usually described as a 'Fatter Agnus', 'Super Agnus', or '1MB
ChipRAM Agnus'. The term '1 Meg Agnus' is also sometimes used, although
strictly this would refer to an 8370 or 8371. The only Agnus that could NOT
address at least 1MB was the original Agnus used in the A1000 and A2000,
which was in a DIP package.
IMO the seller is trying to mislead you. He should have stated that it was
a standard Agnes, which requires NO motherboard modifications to address 1MB
of total RAM (NOT 1MB Chip RAM!).
---------------------------------------------------------------------------
Bruce Abbott Hastings, New Zealand bhab...@inhb.co.nz
---------------------------------------------------------------------------
Lee Howard
On 17 Jul 1996, Brian Middlebro' wrote:
> Opionions needed!!!
> I recently ordered a '1 Meg agnus' over the internet.
>
> When I received it, it was an 8370. I emailed the guy back and he said
> that it will work just as well as any 8372a,8375 AGNUS... And that all that
> was needed was the mother board modification, and it will address 1MEG...
>
> So can anyone help me convince this guy that he is wrong? (8370=1meg agnus)
Sure can...
8370 is NTSC *STANDARD* Agnus
8372a is NTSC/PAL *ECS* Agnus
8375 is NTSC/PAL *ECS* Agnus (but this one is the 2000 one thats
compatible with the A500 also...I just think this is a higher version)
Next...with only the 8370 standard agnus, you can only ADDRESS 512k of
CHIP ram...and CHIP ram is GRAPHICS ram...thats why the GRAPHICS chip
determines if you have 512k or 1 meg of CHIP memory.
If you connect the 8370 (as I have done, just to see if I could access 1
meg of chip)...if you do the 1 meg chip modification to the mother board,
so that the Agnus can address 1 meg of memory space (even though this one
cant), what you will experience is the computer not being able to turn on!
It wont boot, it will go to a guru meditation somewhere in the middle of
its chip initialization.
And if you are able to turn the computer on and it works, then you did
not perform the correct modification to the motherboard for the 1
megabyte ram.
If you use the 8372a or 8375 FATTER agnus (which can address 1 meg or ram
space as all CHIP), you can bend up pin 41 (I believe from memory) and
connect it to a switch...and to ground...so that if it gets grounded, its
NTSC mode, if its not grounded, its PAL mode...also it only determines
what mode at boot up time.
Hey question to you now. Did he state it was a 8372 or higher?
Cuz if he says it can access 1 meg of ram, or does, then thats right,
512k chip and 512k fast...but not 1 meg chip.
The important thing about this 1meg chip is, if you run out of chip
memory, you cant open any more windows/requestors/screens/programs
etc...you may have 6 megs fast, but as soon as you run out of chip
memory, cant open anything else!
Thats why the 1 meg is important, you can open twice as much graphically
than you can the 512k chip.
Good luck!
Justin Eastham
><> I recently ordered a '1 Meg agnus' over the internet.
><>
><> When I received it, it was an 8370. I emailed the guy back and he said
><> that it will work just as well as any 8372a,8375 AGNUS... And that all that
><> was needed was the mother board modification, and it will address 1MEG...
><>
><> So can anyone help me convince this guy that he is wrong? (8370=1meg agnus)
>8370 = 512k
>8372a = 1 Mb
>8375 = 2 Mb
As far as I am aware,
8371 is 512k Agnus found in pre 6a Amiga 500's and 2000's
8372A is 1meg Agnus found in 6a Amiga 500's and 1500's
8372B is 2 meg Agnus found in A500+/A600 (unsure about A3000)
8375 is 2 meg Agnus found in AGA Amigas
As for the 8370, I've never even heard of it !! It may well have come
out of an A1000, as that only had 256k as standard, but that's just a
guess !!
Beard
David Oakes
be...@baynet.co.uk said to :
>><> I recently ordered a '1 Meg agnus' over the internet.
>><>
>><> When I received it, it was an 8370. I emailed the guy back and
>><> he said that it will work just as well as any 8372a,8375 AGNUS..
>><> And that all that was needed was the mother board modification,
>><> and it will address 1MEG...
>><>
>><> So can anyone help me convince this guy that he is wrong?
>><> (8370=1meg agnus)
To the original poster: No Agnus before the 8372A was capable of
addressing 1 meg of chip ram, at least not according to any
information that C= released publicly during that time.
>>8370 = 512k
>>8372a = 1 Mb
>>8375 = 2 Mb
JE> As far as I am aware,
JE> 8371 is 512k Agnus found in pre 6a Amiga 500's and 2000's
AFAIK, the 8371 number was skipped for Agnus numbering, I think it was
used for something else already. Rev 5 A500 motherboards had 8370
512k Agnus chips installed in them, to the best of my recollection.
JE> 8372A is 1meg Agnus found in 6a Amiga 500's and 1500's
JE> 8372B is 2 meg Agnus found in A500+/A600 (unsure about A3000)
The 8372B was installed in the A3000. By the time of the A500+
release, C= was only producing 8375 Agnus chips.
JE> 8375 is 2 meg Agnus found in AGA Amigas
The 8375 -2 was only ever factory installed in the A500+ (rev 8
motherboard) and (I think) in the A600.
No AGA Amiga has an Agnus chip. :)
There are two versions of the 8375, I believe they are differentiated
by a -1 or -2 and are one meg and two meg versions.
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Brian Heyboer
Justin Eastham wrote:
> As far as I am aware,
>
> 8371 is 512k Agnus found in pre 6a Amiga 500's and 2000's
> 8372A is 1meg Agnus found in 6a Amiga 500's and 1500's
> 8372B is 2 meg Agnus found in A500+/A600 (unsure about A3000)
> 8375 is 2 meg Agnus found in AGA Amigas
>
> As for the 8370, I've never even heard of it !! It may well have come
> out of an A1000, as that only had 256k as standard, but that's just a
> guess !!
8370 = NTSC 512K Fat Agnus
8371 = PAL 512K Fat Agnus
Beginning with the 8372A, the video mode is jumper selectable and there are
no separate PAL and NTSC versions.
The A1000 Agnus is not even a PLCC package, its a DIP. Agnus got "fat" in
its A500/2000 incarnation because much of the "glue" logic of the A1000 was
moved inside Agnus.
:=Rob=:
> ><> I recently ordered a '1 Meg agnus' over the internet.
> ><>
> ><> When I received it, it was an 8370. I emailed the guy back and he said
> ><> that it will work just as well as any 8372a,8375 AGNUS... And that all that
> ><> was needed was the mother board modification, and it will address 1MEG...
> ><>
> ><> So can anyone help me convince this guy that he is wrong? (8370=1meg agnus)
Get this. I have a working Amiga 500 with the 1MB modification working
fine --- with an 8372a. I also have a working Amiga 500 with an 8370, so
for your sake, I put the 8370 into the Amiga with the modification
(running OS 3.1). Get this. It actually showed up as having 1MB of CHIP
RAM, but the screen was kinda junked up all over, the pointer had
vertical messes wherever I moved it, it seemed whenever the blitter did
an operation it would trash that region of the display, like scrolling or
dragging a window, dragging screend also did weird stuff. For sanitys
sake I ran a RAM check and everything checked out, but then I decided to
keep opening screens until I passed up the first half megabyte of CHIP
RAM. As soon as I hit the mark it crashed. I would say that the memory
appeared as CHIP RAM because it is (by hardware) wired that way, but that
doesnt mean that the Agnus will access the second half megabyte. Just
for the record, I retested my old Agnus and in my old Amiga and it was
still fine.
Either this guy gives in or you need to play hard-ball.
:=Rob=:
Frank Wille
David Oakes wrote on 08 Aug 96 09:58:51 -400
about "Re: AGNUS despute:8370vs8372a" :
DO> be...@baynet.co.uk said to :
DO> JE> As far as I am aware,
DO> JE> 8371 is 512k Agnus found in pre 6a Amiga 500's and 2000's
DO>
DO> AFAIK, the 8371 number was skipped for Agnus numbering, I think it was
DO> used for something else already. Rev 5 A500 motherboards had 8370
DO> 512k Agnus chips installed in them, to the best of my recollection.
I think there are more 8371-based Amigas in the world than 8370.
8370 = NTSC Agnus 512k
8371 = PAL Agnus 512k
-- _
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Frank Wille
Justin Eastham wrote on Wed, 07 Aug 1996 19:54:30 GMT
about "Re: AGNUS despute:8370vs8372a" :
JE> >8370 = 512k
JE> >8372a = 1 Mb
JE> >8375 = 2 Mb
JE>
JE> As far as I am aware,
JE>
JE> 8371 is 512k Agnus found in pre 6a Amiga 500's and 2000's
JE> 8372A is 1meg Agnus found in 6a Amiga 500's and 1500's
JE> 8372B is 2 meg Agnus found in A500+/A600 (unsure about A3000)
It was used first in the A3000.
JE> 8375 is 2 meg Agnus found in AGA Amigas
The A600 has an 8375, for example. AGA Amigas have no Agnus at all.
JE> As for the 8370, I've never even heard of it !! It may well have come
AFAIK, the 8370 is the NTSC version of the Fat-Agnus, which was
used in north america only. The 8371 ist the PAL version. Since
the 8372A, you can switch between PAL/NTSC by grounding pin 41.
JE> out of an A1000, as that only had 256k as standard, but that's just a
JE> guess !!
The A1000 has an 8360 (NTSC) or 8361 (PAL), which was always
capable of addressing 512k Chip-RAM, although the first A1000s
were distributed with 256k only.
Lee Howard
On Fri, 9 Aug 1996, :=Rob=: wrote:
> fine --- with an 8372a. I also have a working Amiga 500 with an 8370, so
> for your sake, I put the 8370 into the Amiga with the modification
> (running OS 3.1). Get this. It actually showed up as having 1MB of CHIP
> RAM, but the screen was kinda junked up all over, the pointer had
> vertical messes wherever I moved it, it seemed whenever the blitter did
> an operation it would trash that region of the display, like scrolling or
> dragging a window, dragging screend also did weird stuff. For sanitys
> sake I ran a RAM check and everything checked out, but then I decided to
> keep opening screens until I passed up the first half megabyte of CHIP
> RAM. As soon as I hit the mark it crashed. I would say that the memory
> appeared as CHIP RAM because it is (by hardware) wired that way, but that
> doesnt mean that the Agnus will access the second half megabyte. Just
> for the record, I retested my old Agnus and in my old Amiga and it was
> still fine.
Well, thats strange. I performed the same test when a friend sold an
amiga to someone, and took the 8372a agnus out...put in the 8370 agnus
and I also had to change the chip mem mod back to half chip half
fast...but before I did that, I turned it on to see how it behaved, and
it gurued right off the bat...right on powerup after the 3 shades of
grey...guru
So I changed the mod and thats the end of that story.
But yea, it will only adress 512k of chip.
Lee Howard (E-Mail: axj...@freenet.mb.ca)
Kevin Warren
Justin Eastham (be...@baynet.co.uk) wrote:
: 8371 is 512k Agnus found in pre 6a Amiga 500's and 2000's
: 8372A is 1meg Agnus found in 6a Amiga 500's and 1500's
: 8372B is 2 meg Agnus found in A500+/A600 (unsure about A3000)
: 8375 is 2 meg Agnus found in AGA Amigas
: As for the 8370, I've never even heard of it !! It may well have come
: out of an A1000, as that only had 256k as standard, but that's just a
: guess !!
Older Agnuses were the NTSC version and the PAL version (2 different chips)
for the A1000 (48-pin)
PLCC Versions:
8370 = 512K NTSC Agnus on A500 and A2000
8371 = 512K PAL Agnus on A500 and A2000
8372A = 1MB NTSC & PAL Agnus on Rev. 6 A500 and newer A2000s
8372B = 2MB NTSC & PAL Agnus used in A3000
8375 = 2MB NTSC & PAL Agnus used in A500+/A600
|/
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