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Which Versions of EXE

Jamie Chapman

Posts 69
19 Sep 2020 23:05


Hi,

When installing software and there are choice of which CPU to use,  Which is best.  Or does it not matter.  I assumed 060 if it available or 040 if not. 

Also does there need to be any processor libs like there was for 040 and 060 accelerator cards.


Gunnar von Boehn
(Apollo Team Member)
Posts 6197
20 Sep 2020 06:40


Jamie Chapman wrote:

Hi,
 
  When installing software and there are choice of which CPU to use,  Which is best.  Or does it not matter.  I assumed 060 if it available or 040 if not. 

The 68060 misses a number very useful instructions which the 68020/68030/68040 and 68080 CPUs do have.

For example some MUL and DIV instructions.
68060 EXE will therefore replace such MUL instruction with a subroutine. This is of course much slower.

Jamie Chapman wrote:

  Also does there need to be any processor libs like there was for 040 and 060 accelerator cards.

No libs are needed.


Jamie Chapman

Posts 69
20 Sep 2020 11:53


Ok thanks,  so it docent matter which version between 020/030/040 then.  Either of them will give same/similar performance ?


Gunnar von Boehn
(Apollo Team Member)
Posts 6197
20 Sep 2020 12:13


Jamie Chapman wrote:

  Ok thanks,  so it docent matter which version between 020/030/040 then.  Either of them will give same/similar performance ?
 

 
This is not easy to answer. As it will depends on many cases.
I think, I would use 68040 binaries.
 
The 68040 was a very good CPU, code tuned for it should also run fine on 68080.
 
The 68060 added on top the feature to execute 2 instructions in parallel. So code tuned for it might run more parallel.
But the 68060 misses some instructions and was very weak with longer instructions. So coding for 68060 will avoid all this.
 
68080 can also execute several instruction per cycle
but it has no weaknesses like the 68060.
So avoiding long instructions or avoiding the 060-missing instructions is not needed on 68080.
 
 
 


Jamie Chapman

Posts 69
20 Sep 2020 18:55


Thanks

posts 5