Re: ZoomFloppy and HPIB Interfacing

From: A. Fachat <>
Date: Fri, 25 Jul 2014 23:54:00 +0200
Message-ID: <>
There are also subtle changes or restrictions in timing. The PET IEEE488 
routines require the data to be available during a small amount of time 
when reading for example. That is why the drive always reads the first 
block already on open, to have the first byte ready on the actual read.

I and some others have written a firmware to use an atmega as Commodore 
disk drive. You can find it on It 
currently doesn't work on Zoomfloppy because it needs more RAM. But it can 
either be tailored or you can use the IEEE488 routines as inspiration.


Am 25. Juli 2014 22:05:12 schrieb Michał Pleban <>:

> Hello!
> Spiro Trikaliotis wrote:
> > Having said this, I do not know how much the so-called Commodore IEEE
> > bus differs from the GPIB. Is it essentially the same? In this case, you
> > might be lucky with cbmctrl.
> It does not differ at all - it is essentially the same (only the
> connector in the PET is different).
> The problem is that GPIB defines only low-level communication details, a
> bit like TCP/IP. What you build on top of that, the application
> protocol, is up to you. So it's like two computers with a TCP/IP stack,
> but one speaks HTTP and one TELNET - even though the underlying
> low-level protocol (TCP/IP) is the same, it won't allow them to
> communicate unless they agree on the same higher level protocol.
> Regards,
> Michau.
>        Message was sent through the cbm-hackers mailing list

       Message was sent through the cbm-hackers mailing list
Received on 2014-07-25 22:01:05

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