Re: [cc65] Atari sector size detection

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From: Shawn Jefferson (
Date: 2002-10-29 17:23:25

>>> Christian Groessler <> 10/28/02 02:40PM >>>

>I will try the code and see how it works. This is still SpartaDOS
>specific, I wonder whether there is a non DOS-dependent way...

Here is some more info from c.s.a.8 if you are not watching the thread (again from Stefan Dorndorf, this guy seems to know his disk drives!):

>The 1050 sets Bit 7 in $2EA, if the disk is enhanced density. So you
>get the following table for density checking:
>Bit 7  Bit 5    Density
>0      0        Single
>1      0        Enhnaced (Medium)
>0      1        Double
>This works with most drives. Some drives need sector 1 to be read
>before the status command delivers the correct density of the inserted
>disk. But this doesn't work with the XF551. The best way to do a
>density check on the XF551 is to read sector 4 via SIO with $303 set
>to zero (this is to avoid checksum errors, if the sector length in
>$308/9 isn't correct (128 or 256 ?)).

Hope that helps!

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