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Re: cc65: file I/O on external drive?

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From	ol.sc@web.de (Oliver Schmidt)
Newsgroups	comp.sys.apple2.programmer
Subject	Re: cc65: file I/O on external drive?
Date	Thu, 10 Aug 2023 20:08:01 GMT
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Hi Colin,

>This is in fact extremely easy: you just fopen("/PREFIX/FILENAME") and
>it finds the correct drive all by itself :)

Yes, ProDOS is about volumes and paths, not about slots and drives.

However, if you have to access a certain drive then the way to do it
is this:

1. Calculate the device number according to the formula
device = slot + (drive - 1) * 8
(https://cc65.github.io/doc/apple2.html#ss9)

2. Call getdevicedir() with the device from 1.
(https://cc65.github.io/doc/funcref.html#ss3.135)

3. Construct an absolute path from 2. or call chdir() with 2.

If you want to return where you've been before calling chdir(), you
can call getcwd() before chdir().

In general, you might want to have a look at
https://github.com/cc65/cc65/blob/master/samples/enumdevdir.c

Regards,
Oliver

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Thread

cc65: file I/O on external drive? Colin Leroy-Mira <colin@colino.net> - 2023-08-10 15:31 +0200
  Re: cc65: file I/O on external drive? mmphosis <mmphosis@macgui.com> - 2023-08-10 15:01 +0000
    Re: cc65: file I/O on external drive? Colin Leroy-Mira <colin@colino.net> - 2023-08-10 18:03 +0200
      Re: cc65: file I/O on external drive? Colin Leroy-Mira <colin@colino.net> - 2023-08-10 18:22 +0200
        Re: cc65: file I/O on external drive? ol.sc@web.de (Oliver Schmidt) - 2023-08-10 20:08 +0000
          Re: cc65: file I/O on external drive? Colin Leroy-Mira <colin@colino.net> - 2023-08-11 12:07 +0200
            Re: cc65: file I/O on external drive? Oliver Schmidt <ol.sc@web.de> - 2023-08-11 11:31 +0000

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