Re: IWM Does Not Exist?

["Charlie" <charlied@NOSPAMbboard.com>]

"Bryan Parkoff" <nospam@nospam.com> wrote in message
news:8j1mb.3392$%x5.1644@twister.austin.rr.com...
>     I claim that IWM should not exist in an earliest Apple II model in order
> to support GCR format for Disk II Family.

You are right it didn't exist.

>  How do Steve Worniak know to put
> $C080-C08F I/O that he did not invent Disk II Family yet?

Well, that's the way he designed the slots to work.  The Disk II was designed
to work within those parameters.

> He always
> concentrated on tape cassette that it was used for two years.  It is how
> $C080-C08F existed until he started to invent by designing IWM ROM to
> support 5.25" Drive.

Actually, I believe the IWM maps to $C0E0-$C0EF.
I believe tape cassette only used $C020 and $C060.

>     I suspect that $C080-C08F is used for slot 0 only which switch banks of
> 64KB, but it is still useable for slot 1-7 such as LDA $C080,X.

Remember, slot 0 was different.  It didn't allow space for 256 bytes of ROM.

Charlie