Path: utzoo!attcan!uunet!husc6!bloom-beacon!gatech!purdue!i.cc.purdue.edu!j.cc.purdue.edu!pur-ee!uiucdcs!uxc.cso.uiuc.edu!urbsdc!aglew
From: aglew@urbsdc.Urbana.Gould.COM
Newsgroups: comp.arch
Subject: Re: PDP-10 user I/O
Message-ID: <28200154@urbsdc>
Date: 1 Jun 88 03:39:00 GMT
References: <21820@amdcad.AMD.COM>
Lines: 28
Nf-ID: #R:amdcad.AMD.COM:21820:urbsdc:28200154:000:1256
Nf-From: urbsdc.Urbana.Gould.COM!aglew    May 31 22:39:00 1988


>I also would like to see hardware manufacturers make it IMPOSSIBLE
>for operating system writers to prevent use of IO, all instructions,
>etc, by ALL programs. I find it frustrating to find many otherwise
>lovely computers rendered useless to me by an operating system which
>prevents me from writing programs the way I like. How hard would it
>be to have a jumper on the CPU board that would circumvent the bits
>in the PSW that prevent user-mode programs from doing IO and taking
>interrupts?
>
>Doug McDonald

Back into advertising mode, sorry.

Gould UTX supports something called "hardware privilige mode",
so that user programs can do anything the hardware can - and
still enjoy the convenience of UNIX system calls, etc. 
I've been using it for performance measurement programs.


Andy "Krazy" Glew. Gould CSD-Urbana.    1101 E. University, Urbana, IL 61801   
    aglew@gould.com     	- preferred, if you have MX records
    aglew@xenurus.gould.com     - if you don't
    ...!ihnp4!uiucuxc!ccvaxa!aglew  - paths may still be the only way
   
My opinions are my own, and are not the opinions of my employer, or any
other organisation. I indicate my company only so that the reader may
account for any possible bias I may have towards our products.