Re: USB to IEC

Am 3. Januar 2020 13:15:29 schrieb Nate Lawson <nate_at_root.org>:

>> On Jan 2, 2020, at 3:35 PM, André Fachat <afachat_at_gmx.de> wrote:
>> Am 3. Januar 2020 12:14:48 schrieb Nate Lawson <nate_at_root.org>:
>>
>>> I routed the signals on the ZoomFloppy to allow the PC to be used as a drive.
>>
>> So you did something like that already? Is it available somewhere?
>
> No, I just made sure the board would support this case if later desired.
> Never did any software work on it.

Ah I see. Esp. connecting ATN as input as well I guess...

>
>
>>
>>> It would require a lot of firmware work though. You need to bring in
>>> filesystem support in order to enable mounting images like the SD2IEC, for
>>> example.
>>
>> Once you are at the level of IEC logic (Talk/Listen, sec*, iecin/-out) the
>> work is already done in the XD2031 firmware I mentioned.
>
> Neat. The existing xum1541 code could be used as an example or borrowed
> then for your XD2031 project. You’d just have to add USB serial protocol
> support, which is already in the LUFA library and port the various IEC
> routines.

The IEC and IEEE488 routines already exist for xs1541 and petSD, that
should not be a problem. When I looked at the opencbm code I had trouble
finding a starting point how to use the LUFA libs and USB serial for my
purpose. But I didn't have much time.

>
> Certainly this could be built as an alternate firmware for the ZoomFloppy
> board. I’d have to hear a good argument for merging it into a single build
> that is software-switchable between host and drive mode though.

I would prefer making it work first...

> If someone wants to do the work, I can explain where to look in the code.
> BTW, why did you create the XS-1541 when the ZF existed and was fully
> open-source beforehand?

My firmware actually originated maybe 30 years ago when I used my Atari ST
as drive for my PET replica using a self-built IEEE488 interface.
Then I got the hands on an xs1541 (thanks Nils!) and ported it there. It
was apparent that zoomfloppy did not have enough memory to run some serious
firmware. So I started with xs1541.

Some example on how the USB serial is used would help. When I looked at it,
I was iterating between starting from scratch and modifying opencbm, but
both approaches exceed my time budget...

André

>
>
>>
>>> I don’t think the effort of implementing this is worth it, given how cheap
>>> a PI1541 is.
>>
>> Well, there are other use cases that (probably) won't work with the PI1541:
>> when I develop code I just build it into a folder on the PC and reload from
>> the CBM side...
>>
>> But the Raspberry Pi is a viable alternative - if someone builds a
>> driver(?) that provides the IEC logic level e.g. via socket, the XD2031
>> firmware should almost automatically work (I use a socket based driver for
>> the test suite)
>>
>> As far as I understand the Pi does not have enough pins for an IEEE488
>> interface, or does it?
>> How is the ATN response done in Pi1541? In the Atmega world I could use an
>> interrupt for that, would the Pi be fast enough?
>>
>> With XD2031 you then (already now) could mount d64 etc, or even telnet to
>> the internet, or mount ftp or http servers as drives...
>
> No idea on any of these questions.
>
> -Nate
>
>>>> On Jan 1, 2020, at 6:16 AM, Ruud_at_baltissen.org <Ruud@Baltissen.org> wrote:
>>>>
>>>> Hallo allemaal,
>>>>
>>>>
>>>> I just received an email from someone who has a C64, 1541 and a
>>>> modern PC, Windows 10, no LPT or COM port. The 1541 appears to be
>>>> bad and he wants to use the PC as drive. 64HDD is out of the
>>>> question so he needs an USB to IEC solution. But, to be honest and
>>>> happy with my SD2IEC,Ultimate and IEC-ATA, I couldn't think of
>>>> anything.
>>>>
>>>> OK, there is Zoomfloppy but that is the other way around. And I
>>>> wonder if it can be used in reverse mode. So the question: doea any
>>>> of you know of such a device?
>>>>
>>>> He is known with hardware and programming so I gave him the advice
>>>> to at least have a look at SD2IEC as a starter.
>>>>
>>>> Thanks for any input!