Re: Apple IIe + ProDOS = Headache

[Roger Johnstone <rojaws@orcon.net.nz>]

In <avrmd0565p2ot8f011ni2s0m87asft7rf0@4ax.com> Jeff Blakeney  wrote:
> On 23 Jun 2004 07:00:39 GMT, Roger Johnstone <rojaws@orcon.net.nz>
> wrote:
> 
>>(2) ProDOS 1.3 accidentally included a 65C02 instruction in it which 
>>could damage disks if run on a computer with a 6502 CPU.
> 
> First, thank you for posting these corrections.  It saved me the time
> of having to do so but in that last line you did mean:
> 
>      could damage disks if run on a computer with a 65C02 CPU.
> 
> right?  :-)

Not according to Apple, although maybe they were wrong too :o)

ProDOS technical note #23 says:

  ProDOS 8 1.3

  Warning: This is not a stable version of ProDOS due to an
  illegal 65C02 instruction which was added. This version can
  damage disks if used with a 6502 processor.

http://web.pdx.edu/~heiss/technotes/pdos/tn.pdos.23.html

I take it to mean that it was a valid 65C02 but invalid 6502 instruction, 
and was 'illegal' because it shouldn't have been used since 1.3 was not 
supposed to require a 65C02.

-- 
Roger Johnstone, Invercargill, New Zealand
http://vintageware.orcon.net.nz/
________________________________________________________________________
  No Silicon Heaven? Preposterous! Where would all the calculators go?

              Kryten, from the Red Dwarf episode "The Last Day"