2 Nov
2013
2 Nov
'13
11:43 a.m.
Hmm... sadly all of those options seem a bit too slow when you consider that
I would need to sample at 40MHz. The Arduino Due clocks at 84MHz, the Mega
2560 only 16MHz, and the NXP in the DIP is 50MHz. Pity about the NXP that
otherwise looks like just what I would need in terms of packaging.
Have I missed something?
Regards
Rob
start
are
replicate.
build
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Alexandre Souza
Sent: 02 November 2013 17:37
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Looking for a MicroController Recommedation
You have lots of options. I'd use something AVR or ARM. And there are
the
"Arduino" boards which can be used with the
Arduino ecosystem, or used
with a generic C/asm/basic/whatever compiler. If I were you I'd use an
Arduino mega 2560 or the new arduino due, with an ARM processor. Or the
ST (or NXP?) processors, there are new ARM processors (very fast and
powerful) in DIP-28 package.
---
Enviado do meu Motorola PT550
Meu site: http://www.tabalabs.com.br
----- Original Message -----
From: "Robert Jarratt" <robert.jarratt at ntlworld.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Saturday, November 02, 2013 3:25 PM
Subject: Looking for a MicroController Recommedation
>I have been mulling a project to emulate MFM disks (DEC RD53 and RD54 in
> particular) at the disk-to-controller interface. Before anyone asks, I
> don't
> want to interface to Qbus (or any other bus) because I want to emulate
the
least possible
hardware and keep my RQDX3 cards working. And yes, I
know
> this has been talked about many times before, but I want to actually > trying this out.
>
>
>
> My idea is to use some kind of MicroController, talking to specific
> interfacing logic that drives the lines, and using SD memory for the
> actual
> storage. I am considering two approaches:
>
>
>
> 1. Just record the flux transitions in memory and play them back.
> This
> needs me to be able to sample and drive the data lines from the
> microcontroller at 25ns intervals because the pulse width of the flux
> transitions is 50ns. This would need a pretty fast microcontroller, but
is
> my preferred solution as it seems the most
general.
>
> 2. Build custom logic that does the sampling and encodes/decodes
the
> data in 8-bit bytes, so that the microcontroller
would only need to read
> data at a rate of 1 byte every 1.6us. I'd prefer not to do this as it
> requires me to understand the encoding (not too hard I suppose) and
build
custom logic,
and makes the solution possibly a little less general.
I would need a development board that makes it easy to interface to the
SD
> memory on one side and to the custom interfacing logic on the other side
> (perhaps with a serial interface for debugging too), remembering that
> there
> is a 50-pin connector, although only 20 of these are signals, the rest either
reserved or ground. I would need enough onboard memory to store
a
> whole cylinder which is just over 150Kbytes on the RD54.
>
>
>
> If I am successful I would then like to be able to make several more of
> the
> devices, so I would need something that is not too expensive to I
am not sure at this point whether development boards are a good idea for
the
replication or if I would need to then source the actual microcontroller
chips myself and make my own boards. If I have to make my own boards
then
> I
> would need a microcontroller that is available as a DIP because I am
> pretty
> sure surface mounting is going to be beyond me; it would also have to be
> simple enough for me, who is not an expert in electronic design, to > the other components like the volatile and
non-volatile memory, SD
> interface
> etc.
>
>
>
> Looking for recommendations for a suitable microcontroller that does not
> cost the earth ...
>
>
>
> Thanks
>
>
>
> Rob
>