Re: Can an apple II take a C64 microprocessor?

[Rubywand <rubywand@swbell.net>]

Chris Collet writes ...
> 
> Or any other 6502 clone? I'd sure like to get a few more commands than the
> stock 6502 in my II plus. I know that the upgrade for the 65c02 came with
> some extra roms (I have a few sets of those laying around), but could I
> just pop the 6510 or whatever from a commodore 64 and use it in the II+?

> I know I'd have to program in machine code to utilize the extra op codes,
> but I'd sure appreciate the extra commands, such as being able to push and
> pull x and y directly onto the stack. I'm going to try it out anyway since
> I have a busted c64 laying around.

     Won't work. The pinouts of the microprocessors are very different.

     You _may_ be able to swap in a 65C802 (from Western Design Center) and get
several extra opcodes. (One downside is that some early software actually uses
the "undocumented opcodes" on the old 6502.)


>    Also, does anybody know where I can get a "definitive" list of useful
> subroutines in ROM

     There are some good PEEKs/POKEs & Subroutines lists on the Apple II Text
Files site ( http://www.textfiles.com/apple/ ).  Also, see the Csa2 Programmer
FAQs at ftp://rtfm.mit.edu/pub/usenet/news.answers/apple2/programmerfaq/part1 .

> or ones DOS 3.3 puts in ram?
 ....

     The best guide for DOS 3.3 routines is the book "Beaneath Apple DOS" + a
printout of a disassembly listing of DOS 3.3 in memory (which you will probably
have to do yourself from the monitor).



> Although I love writing my
> own multiplication and division subroutines and converting everything from
> ascii to binary and back, I figure DOS 3.3 must have some subroutines for
> handling this (I know there isnt one in ROM).

     DOS 3.3 doesn't really need to do much math. Processing of ASCII character
I/O-- such as from user inputs-- is mainly handled by a few routines in the
monitor.


> And how much of page zero
> does DOS use
 ....

     According to Beaneath Apple DOS, DOS 3.3 uses around 50 or so Zero Page
locations.




Rubywand