Re: Apple II Tape Question?

[dempson@actrix.gen.nz (David Empson)]

Bryan Parkoff <BParkoff@satx.rr.com> wrote:

>     Do Apple II Tape use GCR?

No.  It has nothing in common with the format of data on floppy disks.

The data is stored as raw tones (probably modulated so that a tone
change represents a particular bit value, such as zero).  The data
written to the tape starts with a header, which is used on playback for
synchronization, followed by raw data.  I'd have to look at the monitor
source code to refresh my memory on the details, but my vague
recollection is that it records the length of the data written but
nothing else about it (such as what type of file it might be).  There is
no concept of filenames.  I don't think it uses any kind of sectoring,
but might have a simple checksum for the entire set of data.

> Please provide technical information if you know how it works.

Get hold of a source code listing for the monitor from the Apple ][, ][+
or IIe.  That is all the documentation I know of about the tape data
format.

-- 
David Empson
dempson@actrix.gen.nz