Re: Alternate network and local storage for the Dreamcast

Thanks much for the answer, Izumi!

> Izumi Tsutsui <[email protected]>:
>=20
> lausgans@ wrote:
>=20
>> David Brownlee <abs <at> absd.org> writes:
>>=20
>>> Just found a very interesting Russian site discussing Dreamshell - a
>>> homebrew OS for the Dreamcast.
>>>=20
>>> They have some very nice hardware pages, including schematics for:
>>>=20
>>> - serial to SD adaptor:
>>> =
http://translate.google.com/translate?sl=3Dru&tl=3Den&u=3Dhttp%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
>=20
>> I love how simple SD adapter schematics is (well it's always simple
>> in case of SD :)
>=20
> 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)?

>=20
>> 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.
>=20
> Just FYI, here is my dumb past trial of SD on SCI (not SCIF) on =
dreamcast:
> http://www.youtube.com/watch?v=3Dv80kyFoSAx8
> It's PIO only, still very slow and fragile, write op is very unstable,
> though.

Interesting! I=E2=80=99m seeing it being attached same as you described =
above. Do you plan to bring DMA support?

>=20
>> 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.
>=20
> 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=E2=80=99t reach the site neither directly nor via =
proxy: "503 Service Temporarily Unavailable=C2=BB
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=E2=80=99m looking for a =
non-stock combo of having both network and storage on my NetBSD/DC, and =
while i don=E2=80=99t need fast ethernet, fast enough storage would be =
great.

>=20
> ---
> Izumi Tsutsui

Alex=