Re: Alternate network and local storage for the Dreamcast

[lausgans%gmail.com@localhost]

Thanks much for the answer, Izumi!

> Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>:
> 
> lausgans@ wrote:
> 
>> David Brownlee <abs <at> absd.org> writes:
>> 
>>> Just found a very interesting Russian site discussing Dreamshell - a
>>> homebrew OS for the Dreamcast.
>>> 
>>> They have some very nice hardware pages, including schematics for:
>>> 
>>> - serial to SD adaptor:
>>> http://translate.google.com/translate?sl=ru&tl=en&u=http%3A%2F%2Fwww.dc-swat.ru%2Fblog%2Fhardware%2F14.html
>>> easily available pre-built (google "dreamcast dreamshell sd") online
> The original JJ1ODM page is here (in Japanese):
> http://jj1odm.qp.land.to/dcserial_ft232bm.php#sdcard
> 
>> I love how simple SD adapter schematics is (well it's always simple
>> in case of SD :)
> 
> Unfortunately full manual bitbang ops for SPI is too slow for
> multi task OSes. On the other hand, NetBSD/evbsh3 has SDMMC driver
> using SCIMCI on SH3/SH4:
> http://nxr.netbsd.org/xref/src/sys/arch/evbsh3/t_sh7706lan/scimci.c
> http://nxr.netbsd.org/xref/src/sys/arch/evbsh3/conf/T_SH7706LAN#96
> http://d.hatena.ne.jp/nonakap/20090504/p2
> It's also slow (~20kbyte/sec?), but SH SCI serial also supports DMA
> so it might be possible to use it as a root fs.

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)?

> 
>> What wonders me is whether NetBSD has support for this device?
>> Or anyone plans to add it soon? Would be great to have r/w rootfs
>> on a card.
> 
> 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?

> 
>> The next thing of interest will be ethernet. Well, as serial port will
>> be busy with SD, what will be a best way to attach ethernet? BBA
>> adapters aren't the option, as they cost too much.
> 
> The above JJ1ODM page also mentioned LAN adapter (mbe(4)) compatibles
> and BBA compatible:
> http://jj1odm.qp.land.to/g2bus.php#hit0300_clone

Unfortunately i can’t reach the site neither directly nor via proxy: "503 Service Temporarily Unavailable»
Would be great if one could post a notes in english on how to diy most useful variants of storage and network devices for NetBSD/dreamcast one day.

But is there any faster storage option for DC? I’m looking for a non-stock combo of having both network and storage on my NetBSD/DC, and while i don’t need fast ethernet, fast enough storage would be great.

> 
> ---
> Izumi Tsutsui

Alex