cc65: best way to access the disk?

[ivop]

9 minutes ago, TGB1718 said:

it does

    lda _channel
     clc
     rol a   ; channel * 16
     rol a
     rol a
     rol a
     tax      <<<<< here channel now 16 in x register
     jsr ciov

Instead of CLC and ROL, you could use ASL. It always shifts in zeroes at bit zero. Bit seven goes to the carry bit. Saves one instruction and two cycles

[ilmenit]

Instead of reinventing the wheel what about using these functions?

https://github.com/cc65/cc65/blob/master/include/fcntl.h

https://github.com/cc65/cc65/blob/master/include/unistd.h

Take a look at their code here, they are not that bad:

https://github.com/cc65/cc65/tree/master/libsrc/atari

Edited October 2, 2021 by ilmenit

[TGB1718]

1 minute ago, ilmenit said:

Instead of reinventing the wheel what about using these functions?

https://www.cc65.org/doc/funcref-20.html

Take a look at their code here, they are not that bad:

https://github.com/cc65/cc65/tree/master/libsrc/atari

He said he didn't want to use the C file handling facilities to reduce the memory overhead 

[ivop]

4 minutes ago, TGB1718 said:

He said he didn't want to use the C file handling facilities to reduce the memory overhead 

But there's difference between fopen() and open(). The difference between a full blown FILE structure and a pointer to that, or a file descriptor, which is just an int. After that, use read() instead of fread(), etc...

 

Edited October 2, 2021 by ivop

[ilmenit]

if you look at e.g. https://github.com/cc65/cc65/blob/master/libsrc/atari/open.s then it may be either good enough or a good base for writing own open/read/write/close functions.

[Harry Potter]

I can do that.    Now, what about reading the directory?  BTW, I don't know how to use those functions.

[ilmenit]

11 minutes ago, Harry Potter said:

I can do that.    Now, what about reading the directory?  BTW, I don't know how to use those functions.

Let me Google that for you

http://www.mathcs.emory.edu/~cheung/Courses/561/Syllabus/3-C/bin-files.html

[ivop]

Reading a directory can be done through opendir()/readdir()/closedir(). If you don't want the DIR structure, and bypass libc, you can also use the so-far fictional callciov() and use CIO to read the directory. See "task number 6" at page 86 of Mapping. After opening the directory, it's like reading a file. Read lines until EOF.

[sanny]

3 hours ago, Harry Potter said:

How do I call CIOV?

use _sys() https://cc65.github.io/doc/funcref.html#ss3.14

[ivop]

19 hours ago, sanny said:

use _sys() https://cc65.github.io/doc/funcref.html#ss3.14

So my inline assembly for setting X, and returning Y isn't even needed. I was right in the first place (without knowing), it can all be done in C.

 

[Harry Potter]

Can anybody here post a link to a reference of the different CIOV calls and parameters for me, please?

[drac030]

Here you go: http://atariki.krap.pl/index.php/Dostęp_do_plików

 

Polish, but an automated translator should get this sorted out.

[E474]

There's this list of XIO codes for various DOSs, which are actually CIO calls. https://atariwiki.org/wiki/Wiki.jsp?page=XIO Command Codes DOS Handler

[Harry Potter]

Thank you, E474. 

[Harry Potter]

What about the arguments?

[ilmenit]

https://letmegooglethat.com/?q=atari+CIOV+calls

Edited October 5, 2021 by ilmenit