Check also my newest project, 2,6 Terabyte FireWire Disk Storage.
External case for two 5.25" SCSI devices retrofited to contain four 250 GB EIDE hard drives.
I used four Maxtor MaxLine Plus II hard drives. These drives are kind of "warmblooded",
that's why I mounted two 5.25" bay cooler front plates. Each of them contains two
40x40x10mm fans. So four small fans for air intake and one big one for air outtake cools enough.
IEEE1394 to EIDE Bridge Board FW-142AS is meant to replace old SCSI connectors (50 pin Centronics)
and in such way transform old, small and slow SCSI drives in SCSI casing with new, big and fast EIDE drives.
You can connect two hard drives on each FW-142AS (master/slave or cable select), that's why four drives.
You can see how screws exactly match to fit in old SCSI connector's place.
To keep four 3.5" hard drives in place for two 5.25" devices, I had to mount them vertically.
So I took an old CDROM's housing and drilled in some holes to fix four drives vertically.
Normally CDROM is fixed in second row in casing. Because I lifted it for a half of an inch
I gained just enough space between drives and power supply at the bottom of the casing.
Four drives together.
Remark:
Because 250 GB drive actually show 233 GB in OS, there is only 932 GB (0.91 TB)
of free space available, thanks to marketing trick of hard drive manufacturers
(250.000.000.000 bytes instead of 268.435.456.000 bytes because of
conversion factor 1000 instead of usual 1024 in computer business).