August 3, 2005 on 9:55 am | In Making | 3 Comments

So what’s going inside this crazy mac mod?

The
brains of the beast is a Mini-itx 1Ghz
motherboard
- with built-in graphics, audio and usb/firewire. Almost a whole PC in
a tiny package! There is now a much larger range of these with
multiple
network ports, built in DC invertors, flash/PCMCIA card readers…
They
were originally designed for ‘embedded’ systems such as point-of-sale
tills, information stands, industrial control, and so on. But the
geeks
(such as me) quickly discovered that they were great for sticking into
all kinds of bizarre shells, or cars, or old consoles. Mini-itx.com
has
a great list of
projects on their site – very inspiring!

Although my ‘stock’ motherboard was very small and cute, it
still
wasn’t quite good enough for me yet… the CPU had a tiny fan sat atop
its little heatsink, and unfortuantely this fan emitted a rather
irritating high pitched whine… a slightly larger replacement fan
solved this problem for me.

Also, the first case I put the board into had quite a loud
power
supply – completely ruining the “silent PC” I was tying to create at
the time, noo! Fortunately better minds than I had already created the
PW-70A
snap-in DC-DC invertor.

You
may well be asking “what the hell is that?” Basically it replaces the
noisy power supply that converts mains AC 240V electricity into DC 12V
with a little board that converts DC 12V to the various different
voltages the board requires. To get power to that, we use a
laptop-style ‘brick’ power adapter. As usual there’s a range of them
available online.

So, now that I have a mostly-silent motherboard, what
else?Well, to
make a mini-itx into a full PC you simply need to add some storage
and memory to it. I put a single 512Mb memory bank into the single
slot
available on the motherboard (an unfortunate downside to the smallness
of the board is the consequent lack of upgrade space on it).

A 120Gb 3.5″ hard drive to provides some space for storing
all the lovely media!

To play back DVDs and possibly record/back up data, I have a
slot
loading ‘laptop’ dvd/cdrw drive. It’s a Panasonic CW8123. Why a little
slot-loading drive? Most importantly, I don’t want to mangle the front
of the lovely Mac that all this gubbins is going into – so
slot-loading
is vital. I’m going to copy a trick from a previous Mac mod and simply
widen the floppy dirve slot so that you can pass CDs through it, and
mount the drive the other side. Very neat! A secondary consideration
is
that laptop drives use much less power – the DC invertor I’m using has
a maximum of 100W, and every Watt counts!

Now, the Mini-itx has a perfectly good built-in video card,
it even
has a TV output. But I wanted to be able to run an external display,
as
well as the little touchscreen that would be built into the Mac, so
I� added a Radeon
9200SE
graphics card. They’re pretty cheap
and cheerful, and importantly they don’t have giant fans or heatsinks
on them – cooling is an issue with small PCs and I didn’t want things
to overheat inside the case. This gives me a couple of monitor outputs
and s-video on the same card – so technically I could drive four displays
from this now, but that would just be silly. Ok, more silly than it
already is. (A small technical aside; as the Mini-itx
motherboards only have a PCI expansion slot, I had to get� the
PCI
version of the card. Something to be aware of if building your
own…)

You know what? This post is getting quite long now, so I’ll
have to leave it for now… more tomorrow or possibly later
today.

For now, a sneak peak at the assembled gubbins:

Whoo! Try to contain your excitement as the article continues…
later….