Re: Alternate network and local storage for the Dreamcast

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

lausgans@ wrote:

> Nice. Could you please point me on how to hook to the SH SCI on Dreamcast (though not necessary if you know better options, see below)?

Here it is (from my dumb memo):

---
SCLK	SCK	R140
DI	TXD	R122
DO	RXD	R115

CDET	CTS2	R159

CS	RTS2	R121
---
http://twitpic.com/bjb0ia
http://twitpic.com/bjb104
 (Note this board is dreamcast with MIL-CD support that can boot NetBSD)

dumb patch is here (some MI SH3 files are missing)
https://gist.github.com/tsutsui/9939024

There is no spare GPIO pin on dreamcast so I use RTS2 and CTS2
pins on SCIF serail port for CS/CD.

> > Just FYI, here is my dumb past trial of SD on SCI (not SCIF) on dreamcast:
> > http://www.youtube.com/watch?v=v80kyFoSAx8
> > It's PIO only, still very slow and fragile, write op is very unstable,
> > though.
> 
> Interesting! I'm seeing it being attached same as you described above. Do you plan to bring DMA support?

Not yet.  I have to check hardware and signals for stability..

> But is there any faster storage option for DC?

I also had "dcext" board which supported IDE HDD + NE2000
http://www.youtube.com/watch?v=ctxijoP2gqo
http://movapic.com/ebijun/pic/817076
but it has been broken for years.
The purpose of my SDMMC mod is to make it easier to load
debug kernels for the board without burning CD-R coasters...

---
Izumi Tsutsui