[Color Computer] [Coco] ASM Coders - Round two!

[Charles Richmond]

On Aug 30, 2006, at 9:10 PM, James Diffendaffer wrote:

> --- In ColorComputer at yahoogroups.com, Charles Richmond <richmond at ...>
> wrote:
>
>> The 6502 *does* support position independent code. It just has to
>> be written using PC relative branching. Commodore distributed  
>> something
>> they called a wedge. It was a debugger written in position  
>> independent
>> code so you could locate it in a convenient memory location in
>> relation to the program that you are debugging.
>
> Hmmm... now I'm curious which cpu didn't have position independent  
> code.
>
> I do remember having to use self modifying code for sure.
>
The Intel 8080 did *not* have PC relative addressing and could
*not* produce position independent code.

Using the 6800, some programmers would modify the offset to the
index register in some instructions. That would count as using
self-modifying code.

--
+----------------------------------------------------------------+
|   Charles and Francis Richmond     richmond at plano dot net   |
+----------------------------------------------------------------+





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