andrew@frip.gwd.tek.com (Andrew Klossner) (05/21/88)
[]
"By the way, the KI- and KL-10 processors also reserved a few
addresses in the I/O space to be "unprivileged". That is, I/O
instructions (DATAI, DATAO, CONI, CONO) were allowed to these
few addresses from normal user-mode programs. I'm not sure if
this was ever used by anyone..."
While we're reminiscing, the KA-10 (first PDP-10 if you don't count the
PDP-6) had "user mode", "monitor (supervisor) mode", and "user I/O
mode". This last differed from user mode only in that all of those I/O
instructions were available. I never saw it used, either.
-=- Andrew Klossner (decvax!tektronix!tekecs!andrew) [UUCP]
(andrew%tekecs.tek.com@relay.cs.net) [ARPA]rpw3@amdcad.AMD.COM (Rob Warnock) (05/27/88)
+--------------- | While we're reminiscing, the KA-10 (first PDP-10 if you don't count the | PDP-6) had "user mode", "monitor (supervisor) mode", and "user I/O | mode". This last differed from user mode only in that all of those I/O | instructions were available. I never saw it used, either. | -=- Andrew Klossner (decvax!tektronix!tekecs!andrew) [UUCP] +--------------- Oh, "user I/O" mode got used a LOT by folks in lab environments. Let's see, on the Emory University Chemistry Department's KA-10, we had user-I/O mode programs for doing data acquisition from NMR spectrometers, interfacing to other computers, and even running a line printer. (There was no driver for that particular printer interface, so the driver was coded into the line printer spooler, in user mode.) As I recall, there was even a program that formatted DECtapes in user-mode while timesharing was going on. (The operating system could be requseted to vector certain I/O interrupts to user-mode programs.) Only disadvantage was that they had to be "trusted", since they could take down the machine... Coming forwards to Unix days, the v.7 "phys" call can be used for the same thing, given memory-mapped I/O. At Fortune Systems we used to "phys" call to implement a user-mode driver for a computer-computer channel. User-mode I/O, in general, is a nice "fast prototyping" tool. You can write (most of) your driver in user-mode, without taking down the machine, and then drop it into the kernel only when it works. [No flames about the wisdom or lack of it of doing development with live users around; you still get the advantages of fast turnaround on a "single-user" system if you can avoid a reboot cycle on every compiler cycle.] If you have some sort of "pseudo-device" available (pty's can usually be used, though not always), a rather clean development "platform" can be erected in user-mode, with the slave end of the pseudo-device standing in for the real device, and the "driver" controlling the master end. A friend of mine (Mark Stein) did an entire network protocol package this way once, with the slave ends acting as "sockets", and the "kernel" code running as a user process holding all the master ends. Are we far afield from "comp.arch"? Not really. I claim it is important that new processors/systems allow (though not by default!) user-mode processes to have selective access to I/O registers, for just this sort of "user-I/O". For example, the Am29000 allows any mapped page to actually be in "I/O Space". If I/O devices are allocated rather sparsely in I/O Space (by ignoring the bottom few address bits), one could give a user process access to (say) one I/O port but not another. (You can use a scheme similar to the "PDP-10 Monitor" for vectoring interrupts to "wakeups": Allow a user-I/O program to plant a short code sequence to clear the interrupt and grab time-critical data, while the rest of the processing occurs in user mode.) Paricularly in a PC or workstation environment, such access makes the machine much more userul in laboratory or "real-time" environments, while also making it easier for driver-writers. Rob Warnock Systems Architecture Consultant UUCP: {amdcad,fortune,sun,attmail}!redwood!rpw3 ATTmail: !rpw3 DDD: (415)572-2607 USPS: 627 26th Ave, San Mateo, CA 94403
mcdonald@uxe.cso.uiuc.edu (05/28/88)
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
firth@sei.cmu.edu (Robert Firth) (05/30/88)
In article <46500018@uxe.cso.uiuc.edu> mcdonald@uxe.cso.uiuc.edu writes: >... 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... So throw away the operating system. The purpose of an OS is to add value. When it subtracts value - when the things it stops you doing are more important that the things it provides for you - then it is time to throw it away.
roy@phri.UUCP (Roy Smith) (05/31/88)
firth@bd.sei.cmu.edu.UUCP (PUT YOUR NAME HERE) writes: > So throw away the operating system. [...] When [the OS] subtracts value - > when the things it stops you doing are more important that the things it > provides for you - then it is time to throw it away. I was going to say "you mean like TENEX instead of OS-TEN, or Unix instead of RSTS (or VMS, or Domain, or ...)" but I realized that I can't for the life of me remember the name of the native DEC OS that ran on the pdp-10 (I know I wasn't OS-TEN, but I needed a space-filler). More seriously, other than TENEX and Unix, can anybody think of any "third-party" OSs which replaced the vendor-suplied OS on a given machine to any significant extent? Surely there must be other examples. Does MACH count as an OS, or is it really just a Unix derivitive? If it does count, I guess that would be one third-party OS displacing another! Anybody gotten fed up with SunOS and tried writing their own operating system for a Sun? -- Roy Smith, System Administrator Public Health Research Institute 455 First Avenue, New York, NY 10016 {allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy@uunet.uu.net
bzs@bu-cs.BU.EDU (Barry Shein) (05/31/88)
I'm sure the list of third-party operating systems is much longer than you suspect. I'd guess there were zillions for the PDP-11, tho few were sold, mostly in-house things for various purposes, usually some flavor of real-time work. I've run into a few over the years. Some notable ones (not exclusively PDP-11) are PICK (runs on several architectures), TS-11, MS/DOS (right?), MTS (Michigan Time Sharing, 370 architecture), RAX (370), MUSIC (son of RAX), WYLBUR (370), that OS which ran on 10's which was a library system (I think Boston Public ran one), a few Unix clones come to mind (UNOS, UNIVERS, etc), that LSI-11 O/S that came with the graphics terminal from some university [I think it was sold commercially for a while, was that Cornell?], ITS (PDP-10), WAITS (PDP-10), CTSS, Multics (sort of, consortium effort including vendor, GE), ATLAS (high-brow trivia), HASP (370, NASA), I'm sure I'm forgetting dozens I've run into...the 370 alone probably had dozens, seems I used to run into poor souls supporting such things regularly, then again it seemed like every CMS program became an OS sooner or later...Doesn't Compuserve run their own OS on their 10s? I guess some of those aren't quite "significant", but what the heck... -Barry Shein, Boston University
jkrueger@daitc.ARPA (Jonathan Krueger) (05/31/88)
In article <3327@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: >I can't for >the life of me remember the name of the native DEC OS that ran on the pdp-10 TOPS-10, originally the Total OPerating System, later renamed The OPerating System. I could never tell if DEC was trying to raise expectations or lower them. But lo how the mighty are fallen. It did enjoy twenty years of service. It will be interesting to see which currently widely available operating systems will be remembered when they hit twenty. Will you still need them, will you still feed them? When you've got 64? (address bits, that is). -- Jon Krueger
bzs@bu-cs.BU.EDU (Barry Shein) (05/31/88)
>enjoy twenty years of service. It will be interesting to see which >currently widely available operating systems will be remembered when >they hit twenty. Will you still need them, will you still feed them? Depending on exactly where you start counting from Unix is getting close to 20 years old, the date 1969 is often given as the beginning of development. Even if you're just counting when it was first distributed outside the labs that's around 73-74 so 20 is w/in 1..5 years. I suspect Unix will survive that period more or less intact (if it survives the next 12 months...:-) I was at the Unix 10th birthday party at DECUS, I think that was 84. -Barry Shein, Boston University
hutchson@convex.UUCP (05/31/88)
Third-party operating systems that replaced the manufacturer's system:
Would you count ZCPR{,2,3} on CP/M systems?
... Xenix/Double-DOS/etc. on MS-DOS systems?
Amdahl's Unix(TM) is by some accounts the best way to get Unix
on IBM 370-family systems.
GE's CTSS runs on the Honeywell DPS-8.
Pick, OS-9, Unix, Minix, etc. typically replace some other os.
David Beckemeyer's micro-RTX replaces the Atari-ST's GEMDOS.henry@utzoo.uucp (Henry Spencer) (06/01/88)
> Anybody gotten fed up with SunOS and tried writing their own > operating system for a Sun? This isn't quite so easy for Suns as it was for (say) the pdp11. When you took delivery of a pdp11, you got complete hardware documentation with it... -- "For perfect safety... sit on a fence| Henry Spencer @ U of Toronto Zoology and watch the birds." --Wilbur Wright| {ihnp4,decvax,uunet!mnetor}!utzoo!henry
ejp@ausmelb.oz (Esmond Pitt) (06/01/88)
In article <3327@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: > I was going to say "you mean like TENEX instead of OS-TEN, or Unix > instead of RSTS > ... can anybody think of any > "third-party" OSs which replaced the vendor-suplied OS on a given machine to > any significant extent? As a matter of fact, RSTS was originally a third-party operating system itself. It was written by a firm called Evans, Griffiths and Hart (one version) or a university (another version) and in either case DEC bought the system and the personnel. -- Esmond Pitt, Austec International Ltd ...!uunet.UU.NET!munnari!ausmelb!ejp,ejp@ausmelb.oz
aglew@urbsdc.Urbana.Gould.COM (06/01/88)
>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.
roy@phri.UUCP (06/02/88)
In article <23004@bu-cs.BU.EDU> bzs@bu-cs.BU.EDU (Barry Shein) writes: > Depending on exactly where you start counting from Unix is getting > close to 20 years old More amazing is that troff (if you count its roots back to the old RUNOFF programs on TOPS-10) is probably even older than that. Hardware and Operating Systems may come and go but cranky old applications are here forever. -- Roy Smith, System Administrator Public Health Research Institute 455 First Avenue, New York, NY 10016 {allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy@uunet.uu.net
wcs@skep2.ATT.COM (Bill.Stewart.<ho95c>) (06/02/88)
In article <3327@phri.UUCP> roy@phri.UUCP (Roy Smith) writes:
: Anybody gotten fed up with SunOS and tried writing their own
:operating system for a Sun?
I think the AT&T Bell Labs Research 9th Edition (V9) has been
ported to Suns.
--
# Thanks;
# Bill Stewart, AT&T Bell Labs 2G218, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs
# skep2 is a local machine I'm trying to turn into a server. Please send
# mail to ho95c or ho95e instead. Thanks.hwe@beta.UUCP (Skip Egdorf) (06/04/88)
In article <3330@phri.UUCP>, roy@phri.UUCP (Roy Smith) writes: > In article <23004@bu-cs.BU.EDU> bzs@bu-cs.BU.EDU (Barry Shein) writes: > > Depending on exactly where you start counting from Unix is getting > > close to 20 years old > > More amazing is that troff (if you count its roots back to the old > RUNOFF programs on TOPS-10) is probably even older than that. Actually, TOPS-10 RUNOFF and Unix's ROFF are both siblings on the family tree of the MIT roff program by J. Saltzer. Roff was the stylistic insperation for troff which was followed by nroff (for preview of troff on 'N'ormal terminals). Also of like age is vi / ex / ed / qed ... back to where early teco split from the same family, leading to ITS teco, leading to emacs... They are all related to some extent. Perhaps someday enough of this folklore will be lost to where computer anthropologists (You don't think they are alive??) will be holding learned conferances about troff Robustus and ed Habilis and the relationship between the two. This is getting a bit away from 'arch'itecture and I would like to draw it back a bit. Some reading this might think that the history of our field is not of particular interest. I disagree, and would recommend that at least at the master's level (if not the undergrad), a history of computers course would be useful. I don't mean just the big historical systems read about in an OS or computer architecture course, but a more 'history' like class including the economics and internal political struggles of the industry. I wonder how many of the undergrads drooling over the power of SunOS 4.0's mmap() recognize Multics in the shadows? Skip Egdorf hwe@lanl.gov
johnl@ima.ISC.COM (John R. Levine) (06/05/88)
In article <3330@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: >In article <23004@bu-cs.BU.EDU> bzs@bu-cs.BU.EDU (Barry Shein) writes: >> Depending on exactly where you start counting from Unix is getting >> close to 20 years old > > More amazing is that troff (if you count its roots back to the old >RUNOFF programs on TOPS-10) is probably even older than that. ... Both troff and RUNOFF are descendants of the runoff program for CTSS, which makes them 25 years old, at least. The ctss typset editor seems to finally be dying out. (If your line-at-a-time editor has input and edit modes, toggles between them with a blank line, and has mode prompts like INPUT: and EDIT:, that's typset.) -- John R. Levine, IECC, PO Box 349, Cambridge MA 02238-0349, +1 617 492 3869 { ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.something Rome fell, Babylon fell, Scarsdale will have its turn. -G. B. Shaw
rogerk@mips.COM (Roger B.A. Klorese) (06/06/88)
In article <23002@bu-cs.BU.EDU> bzs@bu-cs.BU.EDU (Barry Shein) writes: >I'm sure I'm forgetting dozens I've run into... Add DTSS (Dartmouth Time-Sharing System) and its descendant, DCTS (Dartmouth College Time-Sharing), on Honeywell (and earlier, GE) systems. -- Roger B.A. Klorese MIPS Computer Systems, Inc. {ames,decwrl,prls,pyramid}!mips!rogerk 25 Burlington Mall Rd, Suite 300 rogerk@mips.COM Burlington, MA 01803 I don't think we're in toto any more, Kansas... +1 617 270-0613