Curious problem witha Sparc 20

[woodland@a1above.net]

Greetings all

I have curious problem with a SparcStation 20
that just got hold of. It seemed to Debian ok
but when it rebooted after the install it gives
me the following message at post:

Level 15 Interrupt
Type help for more information
<#0> ok

What does this mean, and how can I fix it?

This system has a "5x86 SunPc Accelerator" card in it.
I pulled it out but it made no differences.

This system has two 75 MHZ SuperSparc II CPU cards
in it.

This system has turned out to be a disappointment
so far.

Thanks in advance for any help, pointers, and comments

Walt W.