Re: [9fans] PowerPC Booting

[Tomas <psycho@pobox.com>]

On Thu, 3 Jul 2003 at 7:15am, northern snowfall wrote:

> >as well as the nedbsd source.
> >
> Ah, the NetBSD source helped. It solved the fd-just-
> doesnt-seem-to-CLAIM issue. My Power Macintosh refuses
> to boot certain devices if the output-device is set to
> the on-board video.
>
> Booting NetBSD bootdisks blind works properly if output-
> device is set to !screen. However, I have yet-another-
> problem. I don't have a MiniDIN8 serial cable for the
> Macintosh. Nor do I have a null modem.
>
> It seems that I can generate a null modem fairly easily,
> according to:
>     http://www.netbsd.org/Documentation/Hardware/Misc/serial.html#mac
>
> However, I am faced with several problems:
>     a) I have to build my own MiniDIN8 cable
>         1) what wires do i use?
>         2) how do i get the 'connector'...?
>         3) how does it interface with the 'null modem'
>     b) I have to build my own null modem
>         1) see a){1,2}
>     c) I have zero experience with wiring and am extremely
>         nervous about this. I don't want to lose this Mac,
>         even though I bought it cheap.
>         1) every machine is precious
>
> I'd love some assistance in building a serial cable from the
> MiniDIN8 to a standard i86pc serial port. I'm very willing to
> try things out, as long as the factors are known and I'm not
> putting the hardware at a risk of shorting out, etc.
>
> I'm sure there are peopel on this list with experience in
> this area of work. I'd appreciate the help.

Trying to install and run a headless and diskless SGI Indy, I am
also having problems due to MiniDIN8 connectors. It's no fun
changing boot parameters in the PROM and trying to boot diskless
when there's only a keyboard, ethernet and power cable connected
to the machine -- I'd like to see that I really type in correct
values, and also why the boot fails halfway through.

So far it's been impossible to find a MiniDIN8<->DB9 serial cable
(or a MiniDIN8<->DB25 plus a DB25<->DB9 converter), or even a
MiniDIN8 connector. But I hear there's a Mac store near the
Portland airport that might have some... anyways, I've been
thinking about simply cutting off one end of a DB9 cable and
plugging in the wires, one by one, directly into the contact on
the Indy, using the pinout maps on the URL you mentioned above,
as I can't seem to get my hands on a MiniDIN8 connector. Just
haven't had the time yet.

Building a cable isn't that hard. A soldering iron is helpful,
but there are also snap-in connectors for us who don't like
soldering. I doubt there are snap-in connectors for MiniDIN8
though, just DB9/DB25... but the pins on connectors are numbered,
and it's usually a breeze to build a cable if one has
instructions such as those on the NetBSD page.

I'll try to get time to fiddle with this during my vacation, and
if I have any success I'll let you know.

Finally, aren't there some retailers specializing in Mac stuff in
the US, from which one should be able to get a MiniDIN8<->DB25
cable?  That might be the best solution. If anyone knows, I'd
appreciate it if they shared.

/Tomas