[comp.sys.amiga.tech] further A2500 speedup?

rlcarr@athena.mit.edu (Richard L. Carreiro) (09/06/90)

I have an A2500/30 with 1 meg chip RAM and the Super Agnus, and 2 meg of
32-bit memory on the '030 board.

I am running SetCPU1.6 with the FASTROM option.

Given that, will I get anything out of using the programs (called 
MOVESSP [or something similar]) which move the system and/or supervisor
stacks, the main exec structures, and the interrupts into 32-bit RAM?
Or does SetCPU do that?


--
Rich Carreiro                                    The "War on Drugs"
ARPA: rlcarr@athena.mit.edu                      is merely a smokescreen for
UUCP: ...!mit-eddie!mit-athena!rlcarr            The War on the Constitution
BITNET: rlcarr@athena.mit.edu      JITTLOV FOREVER!

daveh@cbmvax.commodore.com (Dave Haynie) (09/06/90)

In article <1990Sep5.171708.8069@athena.mit.edu> rlcarr@athena.mit.edu (Richard L. Carreiro) writes:
>I am running SetCPU1.6 with the FASTROM option.

>Given that, will I get anything out of using the programs (called 
>MOVESSP [or something similar]) which move the system and/or supervisor
>stacks, the main exec structures, and the interrupts into 32-bit RAM?
>Or does SetCPU do that?

SetCPU uses the MMU to relocate the system stack, if it finds the system
stack in Chip memory.  It doesn't try to change VBR (Vector Base Register,
which determines where the vector table used for interrupts and exceptions
is located) or any Exec stuff.  If MOVESSP works without building an MMU
table, it might be useful, and if you run it before SetCPU, you will avoid
moving the system stack twice.  Assuming it works OK in the first place; I
don't anything about MOVESSP except what you've told me.

>Rich Carreiro                                    The "War on Drugs"


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
      Get that coffee outta my face, put a Margarita in its place!

jeh@sisd.kodak.com (Ed Hanway) (09/07/90)

In article <14241@cbmvax.commodore.com> daveh@cbmvax (Dave Haynie) writes:
>SetCPU uses the MMU to relocate the system stack, if it finds the system
>stack in Chip memory.  It doesn't try to change VBR (Vector Base Register,
>which determines where the vector table used for interrupts and exceptions
>is located) or any Exec stuff.  If MOVESSP works without building an MMU
>table, it might be useful, and if you run it before SetCPU, you will avoid
>moving the system stack twice.  Assuming it works OK in the first place; I
>don't anything about MOVESSP except what you've told me.

MOVESSP doesn't use the MMU and should work even on a vanilla 68000.
It does free the Chip RAM used by the original stack (6K, wow) for re-use,
which doesn't sound possible when using the MMU.

Ed Hanway
uunet!sisd!jeh