Re: [cc65] Uniform mass storage device discovery and file locations

From: Oliver Schmidt <ol.sc1web.de>
Date: 2012-08-24 10:41:25
Hi,

> Yes, this is correct. You can just test $90 afterwards.

Will do.

> BTW: JSR $FFB7 (READST) is the "official" way to read the I/O status
> word at $90, that would also work on other machines but the C64.

I see - I was made aware of that already...

> But:
>
> - You cannot clear $90 directly by a KERNAL call (but, you must use
>   another function like CLOSE that resets it. You can close an unopened
>   file number, thus, this might be an option)

I understand.

> - The LISTEN and UNLISTEN functions are not presnet in a CBM KERNAL
>   before C64 (yep, even the VIC20, which is extremely similar to the C64
>   did not have them).
>   Thus, only the C128 (what about C16, Plus/4?) would be other
>   candidates where this might work.

:-(

> So, using READST and the option above to clear the status word might be
> an option for C64 and later machines, but not for machines before that.

Okay, so for now I'll just classify the functionality as C64-only (or
C64 and C128 if I find a clean way to do it) and others more capable
than me have the option to extend it to other CBM machines - is
applicable.

Thanks for all the details,
Oliver
----------------------------------------------------------------------
To unsubscribe from the list send mail to majordomo@musoftware.de with
the string "unsubscribe cc65" in the body(!) of the mail.
Received on Fri Aug 24 10:41:39 2012

This archive was generated by hypermail 2.1.8 : 2012-08-24 10:41:43 CEST