Installing Linux on a Compaq Prosignia

In February 2001 I inherited an old Compaq Prosignia 500 machine, and set about installing Linux on it for a project in a practice. One of the problems I faced was finding a distro that would install easily, and I posted on a Compaq forum about this. About once a month someone mails me a question asking me if I solved the problem. I have. The clips from my email client below are provided to the net in the hope that they will be useful, but please don't mail me: if you've read the page below, you now know as much as me about the matter. My main focus is not in technical support.

Installation:

I had a fair few problems with standard distros on CD to begin with. The CD-ROM in the machine I inherited was SCSI and wouldn't boot a CD. Swapping it out for a new model proved the pragmatic solution, so I presume this was a hardware problem. Machine still wouldn't boot tho', but I eventually used a slackware pre-compiled kernel downloaded from a floppy: it's called n_53c8xx.s; you can download it from any Slackware mirror. That boots the machine nicely from floppy, though it only recognises 16MB of RAM by default (see below). I then got hold of a set of Slackware 7.1 CDs and did a default install.

Problems

I bought XXX megs of RAM, but Linux only sees 16 Megs!!! What gives?

Compaq servers follow the original AT Bios spec, which says that machines can only report up to 16 megs or RAM by a certain BIOS call, even though there are physically enough bits in the register to convey information up to 64 megs (which is what 95% of all BIOS manufacturers do.) Since these machines are EISA machines, EISA calls can be used to determine installed memory, however Linux does not do this. SO-- the solution is to pass the kernel a boot-time argument to tell Linux how much RAM you have installed. If you use LILO, you can test this on your next boot by typing

LILO boot: linux mem=XXM

(It seems to like you to subtract the kernel memory first, but hey, what's a few megabytes here or there?)

(Replace "linux" with your kernel image's name, and the XX with how much memory you have.) If this works, you can add a line at the top of your /etc/lilo.conf file which says

append="mem=XXM"

XXX can be a three digit number, if you've over 100 megs of ram.

Once you've got it working, add it to your /etc/lilo.conf and run lilo for boot after boot satisfaction :-)

In fact, the first time I did this I got a kernel panic... the catch was I had to boot "Linux" not "linux". Press tab at the boot: prompt to find out what yours is called.

Some general background info about the Prosignia 300/500:

From http://potter.ieee.uh.edu/compaq.html

The Compaq Prosignia 300 and 500 are very similar machines internally; they are both single-processor Pentiums machines which use proprietary chipsets, supporting processor speeds of 75 MHz, 90 MHz, 120 MHz, and 150 MHz. They use several industry-standard components:

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Copyright Douglas Carnall 2001. dougie@carnall.org You may reproduce this text in any medium provided this copyright notice is maintained. You may reproduce derivative versions of this text provided that a link to the original version is also maintained.