9. Jensen (DEC 2000/DECpc 150/Highscreen AXP)

Please send comments about this section to Martin Ostermann ( ost@comnets.rwth-aachen.de ).

The Jensen was the first Alpha PC that has been available commercially from DEC. Not surprisingly, there are a few oddities with it. This section is an attempt to help people getting Linux/Alpha installed on a Jensen, and to provide additional information operating Linux on the Jensen.

9.1 Installation

First off, there is no MILO for the Jensen. So it is unavoidable to use Jensen's builtin SRM console. Unfortunately, it is severely handicapped with respect to boot command line option processing. Thanks to Michael Schwingen there is now a new aboot loader that can work around these limitations.

Secondly, the Jensen SRM console cannot boot from a floppy. This used to make bootstrapping Linux a real pain, until Jim Paradis contributed a minlabel and writeboot programs executable from the ARC console. These are available together with a the JENSEN-HOWTO describing the installation process in detail in the JENSEN_INSTALL document. Another version, which you probably want to use, includes a pre-compiled aboot loader and updated installation instructions and is available here .

The Jensen is supported by Red Hat Linux and BLADE_0.2. BLADE_0.2 is heavily outdated nowadays, and you certainly don't want to install it. Last time I checked, Craftworks Linux did not support the Jensen officially. It might work with another kernel image, though.

Anyhow, even with Red Hat Linux you need to get your X Server seperatly, see below.

9.2 The Jensen is different

The Jensen differs from other systems in several ways:

MILO. It was already stated that there is no Milo for the Jensen. This is because the firmware implementation of the Jensen differs somewhat from the one on other systems. PALcode is the keyword to look for, if your interested to know more.
EISA-Bus. The Jensen only got an EISA bus, no PCI. Furthermore, it uses a very special addressing scheme for the bus. While the kernel usually takes care of that in respect to device drivers, it has to be taken care of by utilities that do i/o in user space, like the X servers. Therefore there is a special X server for the Jensen, This server, which supports only S3 based cards, is available from Martin Ostermann's Alpha Page . There is a different (older) version by Stephan Kanthak available via ftp from AZStarNet . You'll also find other useful stuff there, like a ported SVGAlib. If you're interested in details, watch for the keywords SPARSE vs DENSE memory.
RTC. Somehow it was managed to locate the real time clock at a different place (I/O port 0x170 instead of 0x70 on all other machines). Thus the original clock program will fail. A patched version is available from Martin Ostermann's Alpha Page .
Firmware. Since the Jensen is the oldest machine around, there are chances that you got a very old firmware. The date format changed in newer version, which will cause an offset of 20 years. You ought to get a firmware update . WARNING: If you own an ELSA-Winner 1000 graphics adapter, don't update beyond version 1.7! Otherwise you'll not be able to use your card in EISA mode. This is probably due to a bug in the EISA BIOS of the card.

9.3 Known Problems

Know Problem and workarounds:

Date and Time. Due to the location of the real time clock and/or an old firmware. See above.
Won't boot after firmware update. Aboot-0.3 doesn't work with new firmwares. It is known to work with versions up to 1.7.
If you own an ELSA-Winner 1000 graphics adapter and upgraded beyond firmware version 1.7, the card won't work in EISA mode. Turn the card, so that it is plugged in with its ISA side.
Maybe you want to downgrade you firmware again. (Windows-NT 3.51 seems to work fine with firmware 1.7) The problem is, that the older firmware versions are not available via FTP from Digital. If you only got the choice between an very old and a recent one, try to contact your local Digital representative.
aboot-0.x doesn't compile on recent kernels. Get aboot-0.4, it works with recent kernels.
Won't automatic reboot after correct shutdown. Known problem, no solution available so far. On some machines, you even cannot boot by hand, but you have to power-cycle.

9.4 Miscellaneous Information

So what is the Jensen all about? There is a some information available online:

The Evolution of the Alpha AXP PC ( text / Postscript ) by David G. Conroy, Thomas E. Kopec, and Joseph R. Falcone. This describes the development leading to the Jensen system.
Product announcement and description ( text / Postscript ) by Digital. This is an overview of the Jensen system components and options.

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