Date   : Tue, 23 Nov 2010 20:28:55 +0000
From   : philb@... (Phil Blundell)
Subject: Harddisc fakery using a microcontroller

On Tue, 2010-11-23 at 20:08 +0000, Alex Taylor wrote:
> How small could something like this be made? I'm thinking along the
> lines of something 'dongle' sized. that I could easily transport
> between the SCSI ports of Mac Plusses or the other compact Macs I've
> got with dead or missing SCSI hard drives. Something to replace the
> unobtainium 2.5" SCSI drives in earlier Powerbooks would be nice, too.

The SCSI/ATA boards that I had made up were roughly the same footprint
as a 3.5" disk, but you could certainly make them smaller without too
much trouble.  The 50-pin IDC connector is obviously big, and swapping
it for either a Mac-style DB25 or a SCSI-II high density socket would
allow you to shrink the board width quite a lot.  Getting a memory card
plus the translation logic into the same footprint as a 2.5" hard disk
sounds like it should certainly be achievable with a bit of fiddling
around.  It might be easier with discrete flash chips or SD, rather than
a CF card.  

Of course, the smaller you make the thing the harder it is to assemble,
and to some extent it gets more expensive if you start requiring PCBs
with lots of layers.

p.