DEC offered the 166 MHz model specifically for use with Linux (and without Windows NT) under the name UDB (Universal Desktop Box). The pricing was quite attractive.
The Multia, UDB, and Easy Web Server are no longer being sold by DEC (or Compaq). However, DEC dumped a large number of them at fire-sale prices, and there are still some distributors selling them.
udb-man.pdf, Adobe PDF format for Acrobat, 2.3 megabytes
If you are not having problems with your UDB, I don't recommend attempting to install the firmware upgrade. Most UDBs seem to have been shipped with the most recent firmware, and there appears to be very little difference between the old and the new firmware. Some people have reported problems installing the upgrade.
Some configurations of the VX41 and VX42 models are supplied with unusual 12 megabyte SIMMs. These SIMMs will only work in the first pair of SIMM sockets; if you try to use them in the other sockets, or in another system, they will only be recognized as 8 megabyte SIMMs.
The UDB doesn't actually use parity in the conventional sense. The 21066 microprocessor has a 64 bit data bus, with 8 additional bits for ECC (Error Correction Code). If you are running Linux, you may from time to time see ECC messages in the syslog, which look like this:
Nov 6 10:20:23 houhah kernel: lca: machine check (la=0xfffffc0000208490,pc=0x120011250) Nov 6 10:20:23 houhah kernel: Reason: correctable ECC error (short frame, retryable, dc_stat=0): Nov 6 10:20:23 houhah kernel: Correctable read error to b-cache occurred at address 56e9260
If these appear only rarely, they are not a cause for concern. It just means that the ECC is doing its job. On a system with only parity, instead of being corrected and logged, the error would cause a system halt. And on a system with neither parity nor ECC, the error would simply go undetected by the hardware. It could cause a crash, or it could cause some data corruption which might go unnoticed for a long time (especially if the data got written to disk).
If you get lots of ECC correctable error messages in the syslog, or if you get uncorrectable errors, you have cause for concern. This can be caused by defective SIMMs, mis-seated SIMMs, or a defective motherboard. The first thing to try is removing and re-seating the SIMMs. If that doesn't solve the problem, I would suggest trying a different set of SIMMs.
I believe that the following SIMMs sold by Crucial (Micron's retail business) should work, but I haven't tried them:
|capacity||Crucial part number|
Note: On 11-FEB-2002, I received email from someone who purchased a pair of the Crucial 64 MB SIMMs listed above, and is successfully using them in his UDB.
Units incorporating a 3.5 inch disk have a different PCI riser card and mounting bracket. It is not possible to install a PCI expansion card in these units.
The UDB power supply is not capable of powering a second internal hard disk, and may not be sufficient to power even a single high performance drive, such as a Seagate Barracuda. I strongly recommend use of an external drive case.
If you do manage to install a 3.5 inch drive in a unit which originally had a 2.5 inch drive, you'll have to remove (or at least disconnect) the 2.5 inch drive.
As far as I know, there no 2.5 inch SCSI disk drives having storage capacities substantially exceeding 1 gigabyte. The UDB does have an internal IDE interface, with a 44-pin connector for both the IDE signals and power. This connector is commonly used with 2.5 inch IDE drives for portable computers. It is only a plain IDE interface, not EIDE, so it doesn't have any fast DMA or bus-mastering modes.
The necessary 44-pin IDE cable isn't very common, but I've been told that it can be purchased for $10 plus shipping as part number FC530 from Hard Data Ltd. I have not personally done business with them, but several other people who've emailed me have apparently been satisfied customers.
|W9||W12||Mini console (auxiliary)|
|W8 (default)||W10||Normal power-up sequence|
|W7||W11||Causes the system to attempt a floppy boot fail safe load (FSL)|
|W6 to W3||W6 to W3||Under SRM, these jumpers determine the resolution driven to the graphics display|
|W2||W2||When connected to a switch, causes a reset or halt (see J8)|
|J8||J8||When set 2 to 3 causes a reset, when set 1 to 2 causes a halt request CPU interrupt|
|none||W9, W8, W7||CPU speed (see below)|
Note: 1 is jumper removed, 0 is jumper installed.
|W6||W5||W4||W3||Standard||Resolution||Vertical Refresh (Hz)||Pixel Clock (MHz)|
|0||0||0||0||VGA||640 x 480||59.94||25.175|
|0||0||0||1||ERGO VGA||640 x 480||72.79||31.50|
|0||0||1||0||SVGA||800 x 600||60.32||40.00|
|0||0||1||1||ERGO SVGA||800 x 600||72.19||50.00|
|0||1||0||0||VESA 1024x768||1024 x 768||70.07||75.00|
|0||1||0||1||Digital 1024x768||1024 x 768||72.033||74.367|
|0||1||1||0||Digital 1024x864||1024 x 864||60.00||70.00|
|0||1||1||1||1280x1024 60Hz (S3 86C928)||1280 x 1024||60.10||110.15|
|1||0||0||0||1280x1024 66Hz||1280 x 1024||66.51||119.843|
|1||0||0||1||1280x1024 72Hz||1280 x 1024||72.556||130.808|
|1||0||1||0||1280x1024 72Hz (S3 86C928)||1280 x 1024||72.05||130.08|
|1||0||1||1||1280x512 Stereo||1280 x 512||139.336||130.804|
Note: 1 is jumper removed, 0 is jumper installed.
COM1 is wired normally. COM2 is wired using the EIA-232E secondary channel pin assignments where they exist, and other pins (arbitrary?) for the rest.
|Signal||COM1 pin||COM2 pin|
Here are all the variants of the LCA that I have information on:
|Chip Design||Part Number||Rated Speed||Notes|
| 21066 |
|21068-AA||100 MHz||for embedded systems|
| 21066A |
|21066-CB||100 MHz||replaces 21068|
Mitsubishi, a licensed second-source vendor, claimed to offer 200 MHz versions of the original 21066 (LCA4).
Other people have reported that replacing the fan helps.
Last updated February 11, 2002
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002 Eric Smith