Lego A7000 Server
Once again I reused the Acorn A7000 from my previous projects.
- Acorn A7000 motherboard, 32MHz ARM7500, 4MB onboard RAM and RISC OS 3.60.
- Additional 64MB RAM SIMM
- A compact flash to IDE adapter and a 1GB compact flash card.
- EtherH Network Card.
- A green neon light.
- Lots of Lego and a custom printed sticked.
Due to the use of the compact flash instead of a normal HD, and no need for fan cooling, the server proved to be silent in operation.
The server was measured pulling 11W of power under load.
- RISC OS 4.00, Pace internal release, softloaded over 3.60
- or NetBSD 3.1
Photos of case
View from top, with
front panel removed
The basis of the design is a 32x56 base section with 2 wide bricks around the sides of the base, this corresponded almost exactly with the 19" rackmount width. The case is 4 bricks high, with one baseplate layer and one normal plate layer, which is almost exactly 1U high. No planning or measuring was done beforehand, I compared it to a Cisco switch and I was very lucky that everything just seemed to match.
To fit the A7000 PSU inside the 1U height it had to be removed from its metal case (I dont know what the loss of EM shielding will have) and then it tightly fit inside the available height. Given the danger presented by the unproteced mains cables at the rear of the case I used hot glue to fasten the power socket and power switch securly. This glue was the only use of non-lego/non-hardware material in the case.
The design of the rackmount 'rails' that run alongside the case and hold it steady inside the rack, two paralel technic beams are pinned together then a layer of 2-stud-wide plates are placed above and below. This proven more than strong enough for the relatively light case. The rails aren't expandable and were custom fitted for the rack seen in the photos, deeper or shallower racks would need different length rails. The end connections link into the holes in the rack, luckily also the height of the lego unit matched up with with the rack dimensions.
Photos of construction
A early view of the
inside, trying to fit
A close up of
the compact flash
hard drive slot