The BA440 Cabinet

The BA440 cabinet from Digital was the follow-on to the BA213. A labeled picture is shown below. Click on the image to see a larger version of just the cabinet.

Like the BA213, the BA440 takes its Q-Bus cards mounted vertically along the bottom of the cabinet. Unlike the BA213 the BA440 has two doors that swing open from right to left. When they are fully open they can be removed for easy servicing. Drives go into the top and cards with their "bars" go in the bottom. The cabinet uses a 15A right angle IEC plug and can run off wall current.

Features of the BA440

Perhaps the most interesting feature about the BA440 was that accessing the hard drives is much easier. The panel on the drive is shown on the right. This panel is for a DSSI disk drive. Later when SCSI disks are used in this cabinet the panel doesn't have the fault light and nor the ready/run light. There is a captive phillips head screw at the top that keeps the drive in the cabinet. On the back of the drive is an edge connector that plugs into a connection backplane in the drive bays. Another variation is the panel for two half height DSSI drives which has two sets of switches.

Because the drives plug into the backplane on the top there is no cable that snakes its way between the top and bottom of the cabinet. In VAX 4000/200 systems the DSSI interface of the CPU module is brought out to the C/D connectors and automatically routed through the chassis. For the KA640 there is a paddle board in an abbreviated slot to the right of the CPU that can take a honda high density connector to route into that area. With the VAX 4000/300 and later the "CPU Box", which is a set of special slots on the right hand side of the chassis, routes signals up to the DSSI disks.

The power supply is similar to the BA213 in that it is a switcher and won't "light up" unless it has enough of a load. The M9060 card was used in my 4000/200 to provide the load but was absent from the 4000/300.

The DSSI bus is terminated on the left hand side in both a DSSI and 50 pin centronics type connector. Since both DSSI and SCSI used a 50 pin bus either type of drive could be used in the cabinet but they could not be mixed. In the 4000/300 DSSI bus A is routed to the internal peripherals and DSSI bus B comes out the front of the CPU area.

This cabinet looks pretty sharp when it is closed. Personally I think it is an improvement over the BA213 but the BA440 in the later models of VAXen does not have as many slots. The B4000X was an expansion version that just had Q-bus slots and drive bays. The R4000X was full of drive bays.


I've seen several BA440s with TK70 drives installed. The TK70 requires a cable to snake down to the TQK70 in the chassis, the TF85, TF86, and TF87 (DLT drives) actually plug into the DSSI backplane like a disk drive and can actually be run in parallel with the TK70. The slot on the right has some special piece work that makes it easier to put the TK70 there.

The drives in the BA440 have the "EF" mounting hardware. This consists of the front panel, a couple of mounting rails, and the edge connector on the back. The mounting rails include a small 10 pin ribbon cable to connect DSSI drives to the control panel on the front of the drive. As a design methodology goes these are pretty cool drives and one can see evidence of this affecting other designs in later machines. In particular the Storage Works type drives share many similar design concepts although those drives are smaller.

In my collection I currently have two BA440s, one houses a VAX 4000/300 and the other was a DECSystem 5500 (I say was because the power supply does not work and the boards were moved to a BA213)

Back to the House of VAX

Copyright (c) 2000, Chuck McManis, All Rights Reserved

NOTE: All images on this site are COPYRIGHT 2000, 2001 by Charles McManis, you may not use them without written permission from me! (Especially EBAY Auctions!) You may put a link to this site with a note that your system is "like" one of mine but you cannot use the images. Thank you.