Re: Using a Arduino Mage2560 as IEEE disk

I've got one of those boards and it is just a passive shield that interfaces the Arduino to an IEEE connector and an SD card socket; the interesting part will be the developing software.

m

----- Original Message ----- 
From: "Hans Liss" <Hans_at_Liss.pp.se>
To: <cbm-hackers_at_musoftware.de>
Sent: Friday, January 10, 2020 10:10 AM
Subject: Re: Using a Arduino Mage2560 as IEEE disk


> Yes, I've seen it and it looks very interesting. It's the main reason 
> why I would want to keep something like this as simple as possible - as 
> an easily hackable alternative based on a simple "shield" and a standard 
> Arduino Mega doing all of the work in software. I think both variants 
> may be useful, as long as this one is kept simple.
> 
> On the other hand, I've spent all of ten minutes in total looking into 
> this. Maybe it's not very useful after all. I mainly thought it looked 
> cool. :)
> 
> /Hans
> 
> On 2020-01-10 15:39, Christian Dirks wrote:
>> Do you already know the petSD?
>> http://petsd.net/
>> Maybe it's unnecessary to re-invent the wheel.
>>
>> Christian
>>
>> Am 10.01.2020 um 14:52 schrieb Hans Liss:
>>> On 2020-01-10 13:54, Baltissen, GJPAA (Ruud) wrote:
>>>>> Do you know if someone has designed a shield for it already?
>>>> No idea at all. In fact I had no idea what you meant with “shield”.
>>>> Now I know that a shield is a daughterboard that fits on the original
>>>> Arduinoe (or Pi).
>>> Yes, it makes it far more tidy than building it on a separate breadboard
>>> or similar. I've just designed a shield for the mega for testing CDP1802
>>> processors and it turned out very nice.
>>>
>>>>> I'm thinking it should include ...
>>>> Not knowing how the schematic looked like, I had to download and
>>>> install Kicad first. I created a PNG of the schematic and if
>>>> interested, ask me.
>>> Oh, nice! I only read about the pin assignments in the source code, and
>>> that sounded easy enough. I can design and test the shield; I just need
>>> to know what to include beyond the basics.
>>>
>>>> First I haven't any knowledge of the Mega2560 at all so I have no idea
>>>> how the various pins behave: totem pole, OC or something else? What
>>>> they can drive? Can at least one be used as interrupt input? So that
>>>> are things I have to learn first. And that will cost time which I
>>>> don't have very much ☹
>>> If it will help to add drivers or something like that, that can
>>> certainly be done. I don't know anything at all about the IEEE bus.
>>>> I would certainly include an ATN trap. And why not adding an IEC bus?
>>>> If possible parallel to the IEEE one. A small LCD screen + some buttons?
>>> A lot of that will depend on what the software can (be made to) do as
>>> well, of course. But since it's a Mega 2560 there are certainly lots of
>>> pins to play with. I'll look for a hardware interrupt pin - that's
>>> something I haven't played with on Arduinos before.
>>>
>>> As for the IEC bus, I'm not sure how to implement that in parallell to
>>> the IEEE bus. Can that be done with external logic or will the Arduino
>>> have to implement both? TBH, for now I think I would leave the IEC out
>>> of it and just get the basic parallel working the way the author intended.
>>>
>>>
>>> /Hans
>>>
>>>
>>
>