Re: Apple IIe + ProDOS = Headache

[David Wilson <david@uow.edu.au>]

Jeff Blakeney <CUTjblakeney@sympatico.ca> writes:
>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?  :-)

No, P8 v1.3 works fine on an Apple II with 65C02 CPU. If you run it on
an unenhanced IIe or a II or II+ with a 6502 CPU and that bad instruction
is executed the 6502 will NOT branch like the code expects but will instead
fall through into disk writing code and overwrite data on your diskette.
-- 
David Wilson  School of IT & CS, Uni of Wollongong, Australia