Re: How to read IEEE flopies very fast?

I don't remember the speed (it was a long time ago) but ZoomFloppy and
OpenCBM has a utility called d81copy. That can be used to copy SFD-1001 and
8250 disk images (perhaps others too) to and from image files.

2016-09-24 19:44 GMT+02:00 <Ruud@baltissen.org>:

> Hallo allemaal,
>
>
> The subject can be translated into: is there a (open source) speed
> copier available for the IEEE drives, like there is Starcommander
> available for the IEC drives?
>
> If the above answer cannot be answered, please proceed reading.
>
> So far I created by simply reading the sectors one by one by using
> the BLOCK-READ command. My PC issued the command, not a CBM! The
> received bytes were written directly into the image.
> But it takes about 20 minutes to copy one floppy. If that sounds
> bad, that is equivalent to 75 seconds for a 1541 floppy. Rather good
> for standard command, IMHO. But if there can be any speed gained, it
> should be on the drive side. But how?
>
> First: my target is the 8250 drive only.
> Reasons:
> - It can read both 8050 and 8250 floppies.
> - I can create images of 4040 floppies using a 1541 and Star
> Commander
>
> If the 8250 had only one CPU, like the 1541, things would be simple:
> read a byte from the floppy and output it on the bus (using a faster
> protocol). GCR is already taken care of by the hardware so one
> problem less. In fact I would just take SC and alter the source "a
> bit".
>
> But it has two CPUs so that won't work. If you got here, the above
> question about the speed copier couldn't be answered. But that
> doesn't mean that other information or software on this subject is
> available and before inventing the wheel twice, I would welcome
> anything.
>
> Thank you in advance!
>
>
> My idea so far: The FDC CPU keeps reading sectors in a row into some
> reserved buffers. Once a buffer is full, the IEEE CPU sends the data
> to the PC. IMHO three or four buffers are enough. Plus some bytes to
> inform the IEEE CPU what sector has been loaded into a specific
> buffer. After the FDC CPU has read all sectors of a track, the next
> track is read.
>
>
> --
>
> Kind regards / Met vriendelijke groet, Ruud Baltissen
> www.Baltissen.org
>
>
>
>
>
>
>
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