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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: trip6 on September 03, 2007, 03:55:20 PM

Title: 68010 in an Amiga 500
Post by: trip6 on September 03, 2007, 03:55:20 PM

Is upgrading to a 68010 in an Amiga 500 a worthwhile upgrade, are there any caveats or problems to be aware of with th 68010 processor?

Title: Re: 68010 in an Amiga 500
Post by: 57goldtop on September 03, 2007, 04:14:14 PM

I replaced the 68000 in my A500 with a 68010 years ago, some original games and programs did not run.

Here is some info (http://zakalwe.fi/~shd/amiga-cracking/agafix-v1.html)

Quote

The RTE instruction works differently on the 68000 against 68010+. On a 68000 it simply writes the SR and PC back and continues program execution at the interrupted address. On the 68010+ it additionally frees the stackframe depending on the stackframe format.

Some programs push an address (PC) and a SR and then execute an RTE instruction. This works on a 68000 only, but on 68010+ this will have undefinable results.

If a program contains this awful code, you have to emulate it. Sometimes it may be enough to replace the rte with an rtr.

Title: Re: 68010 in an Amiga 500
Post by: Speelgoedmannetje on September 03, 2007, 04:14:28 PM

AFAIK, the 68010 is a 68k with added virtual memory support, so I don't think it's a worthwhile update. Also because of the applications on the Amiga wich might use virtual memory are written for 68020 (or higher) processors.

Title: Re: 68010 in an Amiga 500
Post by: cv643d on September 03, 2007, 04:33:37 PM

If you want to be able to quit to workbench with WHDLoad a 68010 is usefull.

Title: Re: 68010 in an Amiga 500
Post by: trip6 on September 03, 2007, 07:41:12 PM

Quote

cv643d wrote:
If you want to be able to quit to workbench with WHDLoad a 68010 is usefull.

Why is this? Please elaborate?

Title: Re: 68010 in an Amiga 500
Post by: Piru on September 03, 2007, 07:46:30 PM

Because of vector base register (VBR) in 68010. It allows WHDLoad to "patch" interrupts transparently, thus making quitting possible.

Title: Re: 68010 in an Amiga 500
Post by: trip6 on September 03, 2007, 07:48:18 PM

If I have an a500 with a GVP 040 accelerator it won't make a difference either way right because the 68010 will not be used only the 040 on the accelerator right?

Title: Re: 68010 in an Amiga 500
Post by: Piru on September 03, 2007, 07:58:48 PM

Quote

If I have an a500 with a GVP 040 accelerator it won't make a difference either way right because the 68010 will not be used only the 040 on the accelerator right?

Right

Title: Re: 68010 in an Amiga 500
Post by: trip6 on September 04, 2007, 06:47:19 PM

Thanks this is why I love you guys... You are a well spring of knowledge... You are gentlemen and scholars... Have I buttered the muffin enough yet...? Thanks. Nuff said...