[Coco] Micro SD CoCo

[Mike Pepe]

I started some preliminary work on that front.

The Propeller P8X32 is what I was designing around- it has multiple independent cores that run up to 80Mhz- it's more than capable of emulating the WD1773, 6551, MultiPak, etc. Combine it with the flash card reader and it could be a 100% compatible solution.

With work kicking my ass as of late, chances of me finishing it are slim, but someone else may want to investigate it as an option:

http://en.wikipedia.org/wiki/Parallax_Propeller

And if you make something with it, I'll buy it. :)

-Mike

> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of Joel Ewy
> Sent: Wednesday, October 21, 2009 7:02 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] Micro SD CoCo
> 
> This is very cool, Roger.  To make it super ultimate cool, one would
> use
> a CPLD or something like that to mimic the register set of the FDC, and
> have the CPLD (maybe would need the help of a little PIC) communicate
> with the flash memory.  This would be a true replacement for the floppy
> drive, and would work with all software.
> 
> Just a thought...
> 
> JCE
> 
> Roger Taylor wrote:
> >
> > Well folks, tonight I have the CoCo's first Micro SD pak.    This is
> > the same wireless pak model but with a different module plugged into
> > the header.  I just DSKINI'ed DRIVE 0 and saved 2 BASIC programs,
> > typed DIR, and there they are.
> >
> > In case you have never seen how small a Micro SD card is... it's
> about
> > the size of your pinky finger nail.  The module it slides into is
> also
> > small and plugs into the Serial Pak's header but needs an adaptor to
> > match the pins.  Imagine hundreds of floppies, thousands of games and
> > programs, and a full NitrOS-9 system instantly on power-up.
> >
> > This is a serial-based virtual floppy system (CoCoNet) which works
> > much like DriveWire, only there are no wires and the virtual drives
> > are right there in the pak on that little memory card.  I'm using a
> > 2gig card for my tests.
> >
> > The catch?  The CoCo talks to the module @ 115200 bps over the 6551,
> > so there will be some hard-coded Disk BASIC programs that require a
> > real floppy controller and obviously won't work with a virtual drive
> > system, but most programs DO run just fine.
> >
> > I'm still fiddling with how to parition a card to share between Disk
> > BASIC, OS-9/NitrOS-9 and whatever else.  2 gigs is an enormous amount
> > of space for a CoCo system, so even if I have to use 1/2 of the
> card's
> > 512-byte sectors, we're still good, although I don't want to waste
> any
> > space like that.
> >
> > In case you didn't read right... imagine a little game-pak sized
> > cartridge with virtually everything for the CoCo on it!  This will be
> > the case when the pak is finished.
> >
> > The EPROM "firmware" is a patched copy of Disk BASIC.  It needs
> > further tweaking to allow a mix of Drive Pak, Wireless Pak (either or
> > both) without conflict, in a plug-and-play fashion. The CoCo will
> > detect which pak(s) are inserted and communicate with the right
> module
> > or PC server using the same protocol while allowing serial
> > communications as well.  Take a Serial Pak and plug what you want in
> > the header, a bluetooth module or Micro SD module, and the pak should
> > "work" as you expect using the same EPROM with no configuration.
> >
> > Existing Wireless Pak users could swap out their bluetooth module
> with
> > this Micro SD module and pop in the CoCoNet EPROM and be ready, or
> > keep the wireless pak and insert a drive pak, but the paks need their
> > own address, so the code has to detect which addresses/paks are
> > present and automatically set things up when you turn the CoCo on.
> >
> > As for NitrOS-9... I already have this booting over CoCoNet
> wirelessly
> > so I'll just replace the protocol so that either a PC server or the
> > MicroSD module will work the same... read and write sectors.
> >
> > I do need to send off for a run of small header adaptors so the
> module
> > will fit the Serial Pak.  The header just matches a 1x5 header to 2x6
> > header, so it's going to be a tiny board with 90-degree headers on
> > either end and some traces between some of the pins.  In my test I
> use
> > a breadboard with 4 wires run to it from the Serial Pak header.
> > Ground, Tx, Rx, VCC.  That's it.
> 
> 
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