Restoring an InfoTower 1000

Just a few notes from this one.

I rescued some old gear from ACMS with the intent of at least getting some of it operational whilst I kept a hold of it.

One of the items was a DEC InfoTower system with 7 CD-ROM drives.

The InfoTower was a DEC InfoServer 1000 in a steel cabinet (labelled BA56A) , with a single power supply to power it and all the drives connected.  InfoServers could also be used to drive tape and conventional disk units so they could be served to VMS and other systems over an ethernet LAN.

InfoTowers were available with 4 or 7 CD-ROMs, and whilst a lot of photos out there have these with the older caddied RRD42s and similar, the one I picked up has the RRD43 tray drives.

When I got around to inspecting it, it clearly had a blown power-supply – you could smell the electrolyte from the capacitors the moment the rear service cover was removed.

Interestingly enough, the InfoTowers use an old AT-style power supply which plugs into a backplane which connects to the power-connector made available to each drive bay.

You can replace the power-supply fairly trivially with a modern ATX one if you get a ATX to AT power supply loom.  (I picked up one from ebay).  The power supply you install will need to be no bigger than a standard profile power-supply (so the very large monsters like the old Corsair HX1000 are completely out of the question) and needs at least 3 Molex plugs.   The original supply was a 230W supply.  I used a cheap Aywun 500W power supply since I couldn’t get anything smaller with sufficient Molex plugs.

Unfortunately, most of the eBay looms have the switch soldered to them, rather than connected by spades (like the original AT supplies used), which is wasteful and needless as AC-safe spade connectors are quite cheap.  I cut the spade connectors off of the old power-supply’s switch leads and spliced them onto the switch-cable from the loom.  That said, if I had uncrimped spade shoes and insulators, that would have been a better choice than using the old connectors.

One trap to watch, however, is that the pin-out of the P8/P9 connector on the backplane is the reverse of the convention from PCs – whilst the two connectors are side-by-side, you must connect them with the ground wires outside, not in the middle.  (You should double-check this before you swap the supply over, but I doubt there’s that much variance in the units).  Fortunately the PCB is labelled, so a bit of investigative work should help you verify this before you smoke your new power supply.

AUI to 10Base-T (Twisted-Pair) adapters are also fairly easy to get hands on these days too – I was able to pick up a few more so I’ll have enough to hook up my MicroVAXen as well as the Infoserver.