Other PDP11 simulators

From: Scott Stevens <sastevens_at_earthlink.net>
Date: Sun Oct 3 20:04:11 2004

On Sat, 02 Oct 2004 23:46:49 +0100, you wrote:

>Ron Hudson wrote:
>
>>> and simh would run in single-user mode. This would, of course, be silly.
>>
>>
>> why silly? if it would work.
>>
>
>Because none of the userspace daemons would be running. Saying
>"init=/bin/sh" is a great way to get the root filesystem and a command
>prompt and *nothing* else - the init scripts are never run, so no other
>filesystems are mounted, no kernel modules are loaded, nothing like
>that. The kernel loads, brings the console up to a known state, and
>then forks off to the shell. Normally, of course, it would fork init,
>which would then read inittab and then the startup scripts.
>
>Gordon.

Why would the userspace daemons be needed?

Monolythic kernel. No modules.
Filesystem support built in emulator.
etc. etc.

This is somebody who wants bare access to the hardware, the thinnest
possible layer of emulation. Probably they'd be better off launching
it from a DOS session, actually, since Linux isn't really a compact
'program loader' and that's about all DOS really is. Using Linux that
way would be a waste.
Received on Sun Oct 03 2004 - 20:04:11 BST