[comp.sys.amiga.hardware] What's the difference between Fat/Fatter Agnus?

maxc0849@ucselx.sdsu.edu (Human1 ~InnerTangent~) (11/30/90)

	Yes.  What's the difference?

	I ordered my Fatter Agnus.  But I need to know exactly what it does.

	What are the possibilities for this chip (Fatter agnus) ?

	I have heard ALOT about it being able to switch between PAL and NTSC.
Will it work for 1084S monitor?  Need I open the back of the monitor and
readjust the vertical size of the display to make PAL display work?

	I also know that Fatter Agnus gives me 512K more or Chip RAM.  That's
very nice.  But say, If I run 7-8 applications, will the display become very
very sssllllloooowwww?  

	Bad thing about fatter agnus chip?  some software incompatabilities?
Game don't work?

	I'm sure there must be more pro and cons I'm overlooking.  Please
fill me in on these details.  Any comments, advices, informations, anything,
Welcome!

Thank you very much.

huebner@aero.aero.org (Robert E. Huebner) (11/30/90)

In article <1990Nov29.221638.28294@ucselx.sdsu.edu>,
maxc0849@ucselx.sdsu.edu (Human1 ~InnerTangent~) writes:
|> 
|> 	Yes.  What's the difference?
|> 
|> 	I ordered my Fatter Agnus.  But I need to know exactly what it does.
|> 
|> 	What are the possibilities for this chip (Fatter agnus) ?
|> 
|> 	I have heard ALOT about it being able to switch between PAL and NTSC.
|> Will it work for 1084S monitor?  Need I open the back of the monitor and
|> readjust the vertical size of the display to make PAL display work?

I posed this same question some time ago.  Email responses have led me
to believe that:

- All 1084S and 1084 models that look identical physically to the 1084S will
automatically squeeze the vertical height of the screen when a PAL scan rate
is applied
- All other monitors (1080, 1084D, etc) will require adjust (the control
for which seems very fragile and I have already destroyed it on one of my
monitors.  So beware!

One solution is to leave the monitor in PAL mode (the potentiometer will be
at it maximum/minimum level (ie: cranked all the way in one direction) and
cope with the black space left when NTSC programmes are running (like most
European users have to)

|> 	I also know that Fatter Agnus gives me 512K more or Chip RAM.  That's
|> very nice.  But say, If I run 7-8 applications, will the display become very
|> very sssllllloooowwww?  

I haven't noticed this.  Perhaps if you have 512K of true fast mem that you
change over to chip mem it would slow some things (since Chip mem is slower)
but on A500s, the fast mem on board is actually slow-fast mem (or, fast mem
at chip mem speeds) so it shouldn't matter.

|> 	Bad thing about fatter agnus chip?  some software incompatabilities?
|> Game don't work?

Some.  Very few though.  Wayne Gretzky's Hockey comes to mind.  Some games
run better (kinda)  For instance - my old version of Balance of Power, which
(due to stupid programming) has trouble with fast mem works without the
nofastmem patch on a 1mb Agnus system.  There are a lot of british import
games (if you're into such things) that require the computer to be in PAL 
mode lest the program crash. 

There is also a utility called KillChip that will help in those rare cases
where 1 Mb Chip is a problem. (again, I don't know of more than 1)

|> 	I'm sure there must be more pro and cons I'm overlooking.  Please
|> fill me in on these details.  Any comments, advices, informations, anything,
|> Welcome!

The only other thing to be aware of is this: if you have some sort of non-
standard memory expansions (ie: Baseboard), you will not want to follow the
normal procedure for changing jumpers to get 1 Meg Chip RAM.  If you are
planning to add such a device shortly, get it now and save yourself the 
trouble of having to re-solder wires later.

Also check to make sure that any autoconfig memory you will will still 
autocofig with the Fatter (Obease) Agnus installed.  Some (again, Baseboard
in personal experience) won't.

|> Thank you very much.

I'd like to add two questions to this thread:

-- How can I fix my monitor to auto-adjust like some of the 1084's do?  
Or alternately, what are the proper POT resistances for NTSC and PAL screens?
Would a dual resistor path with a switch be concievable, or is the line running
through that adjustment a high voltage one?  I'm no TV repairman (and I know
monitors are dangerous to work on), but if I give my dealer specific
instructions
they might be able to do it.  I suppose only a CBM hardware guru or an avid
schematics reader would know this, eh?

-- Where is resistor J102 on an A500.  This is the infamous NTSC/PAL switch,
which of course I was unable to find last time I had the case open (gasp!
voided warranty!)

-----
Robert Huebner		huebner@aerospace.aero.org
			The Aerospace Corporation
"Let's face it, the NeXT is strictly for computer geeks." - Anonymous
-----

smp@myamiga.UUCP (Steven M. Palm) (12/03/90)

>In article <92928@aerospace.AERO.ORG> huebner@aero.aero.org (Robert E. Huebner) writes:
>In article <1990Nov29.221638.28294@ucselx.sdsu.edu>,
>maxc0849@ucselx.sdsu.edu (Human1 ~InnerTangent~) writes:
>|> 	Bad thing about fatter agnus chip?  some software incompatabilities?
>|> Game don't work?
>
>Some.  Very few though.  Wayne Gretzky's Hockey comes to mind.  Some games
>run better (kinda)  For instance - my old version of Balance of Power, which
>(due to stupid programming) has trouble with fast mem works without the
>nofastmem patch on a 1mb Agnus system.  There are a lot of british import
>games (if you're into such things) that require the computer to be in PAL 
>mode lest the program crash. 
>
>There is also a utility called KillChip that will help in those rare cases
>where 1 Mb Chip is a problem. (again, I don't know of more than 1)

I had posted this before, but I am not sure if it got out.  In any case, it
has direct bearing on this discussion so I will post again.

I have heard the rumours go on for quite a while that Wayne Gretzky Hockey
and other programs would simply not work with the Newer Fat Agnus installed.
I was frustrated.  I found that the following two programs will allow me to
run it without a hitch.
 
 KILLCHIP
 NOFAST
 {Re-Boot with W.G. Hocky in DF0:}

This is the version of KillChip I used.  I know there are several
floating around, so I feel it necessary to post the one that I know
worked for me.

---------->8-----------v cut here for killchip v--------8<--------- 
begin 644 KillChip
M```#\P`````````"``````````$````_`````0```^D````_,_Q```#?\)HLH
M>0````1![@%"(%!*D&<``'8B:``*(`EK\`R10VAI<&;H#*@`"````!AEWB0\4
M`!```)2H`!@B/``(``"2@B)H`!`@"="I``1*D6<.#(``"```9```,B)18.B3F
MJ0`$DZ@`''`(2$`M0``^D((A0``8<@!![@`B<!?26%'(__Q&03"!?@!@!'X*D
M=`!X"$A$*@0D1-J%FH(@1'0@T<)"D"8%EH1T():"(4,`!#5\"G\`""5\`/P#I
M,@`*-7P`!0`.)40`%"5%`!@E2``0)@66A'0@EH(E0P`<(DI![@%"3J[_$#/\)
JP```W_":(`=P`$YU```````````#[`````````/R```#ZP````$```/R+
``
end
size 312
---------->8-----------^ cut here for killchip ^---------8<---------

And here is the version of NoFast that I used.  I found that NoFastMem
would not have the same results.  

---------->8-----------v cut here for nofast v-----------8<--------- 
begin 644 NoFast
M```#\P`````````!``````````!````$0``#Z0````0L>0````1.KO]J3OD``
'^``````#\@``M
``
end
size 52
---------->8-----------^ cut here for nofast ^-----------8<--------- 

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