gordon@jc3b21.UUCP (06/08/87)
I am not trying to insult Mr. Tanenbaum and MINIX. I think MINIX is the
greatest educational "UNIX TOY" around and can compliment the effort and
the method of distribution with the highest praise, however, I have
been here before with "VIRGINS" and have very little hair left to pull out.
I was there with "OS9" and "UNIFLEX" and a couple other efforts on micros
a few years back trying to get them to run in a semi-commercial atmosphere
and this whole MINIX process is like "DEJA-VU" to me. There are some glaring
problems with using MINIX as even a toy development system that have stopped
me dead in my tracks. I will list some of them and I am sure someone has
posted previous comments about that I have missed.
(1) the C compiler and MINIX upchucks floating point numbers at run time.
the documentation coyly warns of this. God, how do you write any kind
of applications even for fun only without real numbers?? HELP!!
(2) The boot operation leaves me wondering why a hard disk was not used
right off the top. Who would ever try to run UNIX on floppies??
(3) There is no multi-user capabilities provided as I read it. I only
need one for testing purposes. I know the processor is brain dead and
that is the basic problem. Has anyone written a /dev/tty02 or higher
that works??
(4) The / directory is a flying joke. This must be because of the need to
use 2 floppy drives instead of a hard disk. If you accidentally copy
a large directory into slash / you are up for some entertainment.
(5) The ram disk uses up too much memory that could be used by other tasks.
Can this be killed and sent to disk where it belongs??
(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say?
(7) MINIX does not appear to work with more than 640k of ram. Can this be
expanded??
(8) This is a rephrase of #2 above: can you boot directly to hard disk
without any floppys? I can get /dev/hd0 to work as /dev/hd0 but I
can not boot directly to /dev/hd0.
(9) FSCK should be renamed "Fragment,Crash,Collate,Kill". If you use an
entire hard disk partition for MINIX which works fine by the way, FSCK
will screw it up because FSCK is expecting partitions 1-4 and not
partition 0.. If I ignore running FSCK I have no problems.
Hopefully some of my
complaints have been considered for solutions pending by the author or
users. I would love to see MINIX reported to a 68000 or higher where it
could really be let go!! THANKS FOR YOUR HELP IN ADVANCE,
R. Gordon Price
Century Computer Systems Inc.
P.O. Box 58133
Tierra Verde Florida 33715
(813) 864-2678
FAX (813) 867-0822beattie@netxcom.UUCP (Brian Beattie) (06/09/87)
In article <114@jc3b21.UUCP> gordon@jc3b21.UUCP (R. Gordon Price) writes: >(2) The boot operation leaves me wondering why a hard disk was not used > right off the top. Who would ever try to run UNIX on floppies?? Me >(3) There is no multi-user capabilities provided as I read it. I only > need one for testing purposes. I know the processor is brain dead and > that is the basic problem. Has anyone written a /dev/tty02 or higher > that works?? I believe such was posted although I have not had a chance to try it out. >(4) The / directory is a flying joke. This must be because of the need to > use 2 floppy drives instead of a hard disk. This is exactly so it can be run from floppies. >(5) The ram disk uses up too much memory that could be used by other tasks. > Can this be killed and sent to disk where it belongs?? Yes. >(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say? Add it your-self. >(7) MINIX does not appear to work with more than 640k of ram. Can this be > expanded?? You have the source. >I would love to see MINIX reported to a 68000 or higher where it MINIX(Or UNIX) will not work easily on the lower end 68000 machines due to lach or hardware relocation. (no MMU). >could really be let go!! THANKS FOR YOUR HELP IN ADVANCE, > >R. Gordon Price >Century Computer Systems Inc. >P.O. Box 58133 >Tierra Verde Florida 33715 >(813) 864-2678 >FAX (813) 867-0822 In short I think you missunderstand Dr. Tanenbaum's purpose. If you read the preface to the book I think you will find that MINIX was intended as a teaching tool. In fact I think that Dr. Tanenbaum is very suprised to find people trying to use MINIX for real. The restriction of having to run on a floppy only system is so that students might be able to work with MINIX on inexpensive machines. Finally unlike other operating systems available the source for MINIX is available inexpensively and if any-thing bugs you you are free to change it. If you want a REAL operating system go buy one. -- ----------------------------------------------------------------------- Brian Beattie | Phone: (703)749-2365 NetExpress Communications, Inc. | uucp: seismo!sundc!netxcom!beattie 1953 Gallows Road, Suite 300 | Vienna,VA 22180 |
zemon@felix.UUCP (06/09/87)
Feeling verbose today, I offer my comments, some sarcastic (to be taken in fun, not as flames), and some serious. In article <114@jc3b21.UUCP> gordon@jc3b21.UUCP (R. Gordon Price) writes: >(1) the C compiler and MINIX upchucks floating point numbers at run time. > the documentation coyly warns of this. God, how do you write any kind > of applications even for fun only without real numbers?? HELP!! What's a real number? If it cannot be expressed as a quantity between -2^31 and 2^31, do you really need to express it at all? I guess my hacking tends toward integers since I can only remember one floating point program which I have written in the last few years (mortgage payment approximation). Even the stuff I do which deals with money counts integer pennies. >(2) The boot operation leaves me wondering why a hard disk was not used > right off the top. Who would ever try to run UNIX on floppies?? The only reason I would want to run Minix on floppies would be if I had to go back to college days when a hard disk was beyond my means. Minix does run nicely on two floppies and I did quite a bit of kernel hacking to get it up on my hard disk in that environment. >(3) There is no multi-user capabilities provided as I read it. I only > need one for testing purposes. I know the processor is brain dead and > that is the basic problem. Has anyone written a /dev/tty02 or higher > that works?? Someone posted an RS232 driver a few days ago. If you cannot find it then I can mail you a copy. I have not run it yet but.... >(5) The ram disk uses up too much memory that could be used by other tasks. > Can this be killed and sent to disk where it belongs?? Most certainly! The "patch" involves gutting the routine inside the file system which loads the RAM disk (I think it is called "load_ram"). I can mail you my code if you want. I could also mail you a boot floppy which uses /dev/hd1 as the root file system. I also have a combined boot and root file system floppy. >(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say? Now that I have a RAM disk which is zero bytes long, I have 540K of available memory. My poor CPU runs out of steam long before I run out of memory. >(8) This is a rephrase of #2 above: can you boot directly to hard disk > without any floppys? I can get /dev/hd0 to work as /dev/hd0 but I > can not boot directly to /dev/hd0. I suppose you could if you wanted to run Minix exlusively. I have my system set up so that I get MS-DOS by booting from the hard disk and Minix by booting from my Minix boot floppy. This is the only floppy I use since my root (and only) file system is on the hard disk. As soon as I type "=", Minix is running. >(9) FSCK should be renamed "Fragment,Crash,Collate,Kill". If you use an > entire hard disk partition for MINIX which works fine by the way, FSCK > will screw it up because FSCK is expecting partitions 1-4 and not > partition 0.. If I ignore running FSCK I have no problems. Hmmmm. I have no trouble with fsck on /dev/hd1. Have you tried making partition 1 the entire disk and using /dev/hd1 instead of /dev/hd0? -- -- Art Zemon FileNet Corporation Costa Mesa, California ...!hplabs!felix!zemon
eichin@athena.mit.edu (Mark W. Eichin) (06/10/87)
In article <161@netxcom.UUCP> beattie@netxcom.UUCP (Brian Beattie) writes: >If you read the preface to the book I think you will find that MINIX was >intended as a teaching tool. In fact I think that Dr. Tanenbaum is very >suprised to find people trying to use MINIX for real. Gee, didn't someone once attribute a similar statement to N. Wirth, about Pascal? No I/O, just a teaching language, Really, No kidding! :-) Mark Eichin <eichin@ATHENA.MIT.EDU> /Happy Hacking...........\ \.............Mark Eichin/
dboyes@uoregon.UUCP (06/10/87)
In article <114@jc3b21.UUCP> gordon@jc3b21.UUCP (R. Gordon Price) writes: >I am not trying to insult Mr. Tanenbaum and MINIX. I think MINIX is the >greatest educational "UNIX TOY" around and can compliment the effort and >the method of distribution with the highest praise, however, I have >been here before with "VIRGINS" and have very little hair left to pull out. >I was there with "OS9" and "UNIFLEX" and a couple other efforts on micros >a few years back trying to get them to run in a semi-commercial atmosphere Whoa. I think you're missing the point here. Minix was never intended to be a production OS like OS9 or Uniflex. It's an EXAMPLE (admittedly one jim-hell of an example) intended to be something that students studying OS design can look at, tweak, fix, break, fix again, improve, etc., all while gaining a darn good understanding of how to design & implement OS code. Andy T. never claimed that Minix was anything but an educational tool. >and this whole MINIX process is like "DEJA-VU" to me. There are some glaring >problems with using MINIX as even a toy development system that have stopped It's not a development system -- it's an example intended to accompany a course in OS design -- it'd be useful in a compilers course, too. See above. >(1) the C compiler and MINIX upchucks floating point numbers at run time. > the documentation coyly warns of this. God, how do you write any kind > of applications even for fun only without real numbers?? HELP!! Simple enough. Most (more than 65%) of the applications written in the "real world" don't need floating point math, or can be written to minimize the use of such operations with a little thought. Besides, it's really in keeping with the educational orientation of Minix -- you need floating point, fine, go write it. You have source -- go for it. >(2) The boot operation leaves me wondering why a hard disk was not used > right off the top. Who would ever try to run UNIX on floppies?? Matter of cost. Educational institutions (and the rest of us underpaid slobs out here) are not exactly loaded with cash these days. LOTS of people have floppy-only systems. Visit your local state university some time -- I'd wager that a vast majority of the systems don't have fixed disks. Minix will run on floppies in order to minimize the cost of the equipment required to run it. >(3) There is no multi-user capabilities provided as I read it. I only > need one for testing purposes. I know the processor is brain dead and > that is the basic problem. Has anyone written a /dev/tty02 or higher > that works?? Are you serious? 2 or more users on a 4.77 MHz 8088? Remember that not everyone has AT-class machines, friend. Someone posted a /dev/tty02 driver not too long ago, and again, you have source -- go to it. >(4) The / directory is a flying joke. This must be because of the need to > use 2 floppy drives instead of a hard disk. If you accidentally copy > a large directory into slash / you are up for some entertainment. Agreed. However, Minix is very like Sys 7 Unix on the old PDP-11's, and they handled / exactly like Minix does. Blame this one on the model, not Minix. 2.9 BSD has this problem, too. >(5) The ram disk uses up too much memory that could be used by other tasks. > Can this be killed and sent to disk where it belongs?? Care to swap disks every time you want to do a cat foo? I don't. Besides, you can change the size of the RAM disk to anything you want and recompile the kernel. To quote an old beer commercial, "Fix it yourself, ape man!" >(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say? Sys 7 didn't swap either -- this ain't vmunix. Plus, you have to take into consideration hardware constraints -- you can't swap to floppies -- you yourself complained about how slow floppies are. Memory management code would have been an improvement, however I don't know of a memory management unit for the 8088, do you? Requiring memory management hardware would have made it next to impossible for many of use to afford to run Minix at all. Just as a quick comparison, how many private individuals do you kinow that have sprung the $150 or so for an 8087? Not many, I'd bet. >(7) MINIX does not appear to work with more than 640k of ram. Can this be > expanded?? Well, you have a 1 M address space in the base PC, much of which is occupied by IBM ROMs that are pretty tough to deselect. If you have a 286 based environment you could use protected mode memory, but Intel's brain-dead way of accessing it almost defeats the purpose. You could use LIM or EMS boards, but then the cost issue comes up again. Even Aboveboard clones aren't cheap. YCAHTKTDAYW. (You Can Always Hack The Kernel To Do Anything You Want) >(9) FSCK should be renamed "Fragment,Crash,Collate,Kill". If you use an > entire hard disk partition for MINIX which works fine by the way, FSCK > will screw it up because FSCK is expecting partitions 1-4 and not > partition 0.. If I ignore running FSCK I have no problems. A patch for this was posted early on. > Hopefully some of my >complaints have been considered for solutions pending by the author or >users. I would love to see MINIX reported to a 68000 or higher where it Somoene already has a NS32K port, and Since You Have Source, a 68K port wouldn't be all that tough. Go to it. In a lot of ways, you're trying to make something out of Minix that it wasn't intended to be. If you want a production OS, go buy SCO Xenix V.3 or Microport Xenix -- they're intended to be what you're talking about. Minix is an educational gadget and a grand example -- you could consider it a problem set in OS design. It's cheap, requires minimal hardware, and is exceptionally well documented (do you get anything like The Book with your AT&T source license?). Besides, for $75, I'm willing to do a little hacking to add features; after all it's saving me buyin an AT($2k), a 40 or 50 meg hard disk (~$800) and Xenix ($1200). > >R. Gordon Price >Century Computer Systems Inc. -- David Boyes ARPA: 556%OREGON1.BITNET@WISCVM.WISC.EDU Systems Division BITNET: 556@OREGON1 University of Oregon Computing Center UUCP: dboyes@uoregon.UUCP
beattie@netxcom.UUCP (06/10/87)
In article <879@bloom-beacon.MIT.EDU> eichin@athena.mit.edu (Mark W. Eichin) writes: >In article <161@netxcom.UUCP> beattie@netxcom.UUCP (Brian Beattie) writes: >>If you read the preface to the book I think you will find that MINIX was >>intended as a teaching tool. > >Gee, didn't someone once attribute a similar statement to N. Wirth, >about Pascal? No I/O, just a teaching language, Really, No kidding! :-) > >Mark Eichin ><eichin@ATHENA.MIT.EDU> > > /Happy Hacking...........\ > \.............Mark Eichin/ You Are quite right and people have found it necessary to extend the language. The point I was trying to make was that MINIX was designed as a teaching tool, as such it looks like an excelent tool. I am however using it as a real operating system and as such it has a few problems. But I got source and I figure I can fix or "borrow" fixes that others post complaining that MINIX lacks this or that will get us nowhere. I would close by saying if you don't like the way MINIX works, change it. -- ----------------------------------------------------------------------- Brian Beattie | Phone: (703)749-2365 NetExpress Communications, Inc. | uucp: seismo!sundc!netxcom!beattie 1953 Gallows Road, Suite 300 | Vienna,VA 22180 |
ast@botter.UUCP (06/10/87)
In article <114@jc3b21.UUCP> gordon@jc3b21.UUCP (R. Gordon Price) writes: >There are some glaring problems with using MINIX... Most of the problems are caused by my desire to make the system run with a 256K 1 floppy disk system, and run reasonably well with a 640K 2 floppy disk system. In other words, I do not assume that people have a hard disk. Why? A recent survey in a local computer hobby magazine showed that only 5% of the readers had a hard disk. 95% worked with floppy only. In my own dept. I know that very few students have hard disks, and even among the faculty members here who have a computer at home, I believe that I am the only one with a hard disk. Obviously for a corporation $500 more or less for a PC doesn't make much difference (unless, like American Airlines just did, the corporation orders 8000 at a time, in which case the issue is at least worth thinking about). For students who have to borrow money from the bank to pay their tuition and have to eat at the university cafeteria 3 times a day because that is all they can afford, acquisition of a hard disk is a major purchase that has to be weighed against other ways to spend money. As time goes on and hard disks get cheaper, this issue becomes less critical and the situation may change. For the time being, I don't want to ignore these people, as all the other UNIX systems have done. Your specific comments: 1) No floats. I agree, they would be nice, but I haven't personally used a number > 32767 in years. Is anyone working on floats? 2) Who would ever try to run MINIX on floppies?? Poor people. 3) Multiuser. See Andrew Valencia's posting of last week for multiuser. 4) The / directory is a flying joke. Every system works poorly when the disk is full. Most users work in /usr/something not /. Again, with floppies only, space is definitely cramped. 5) RAM disk is dumb. On a floppy system it is critical. 360K is too small for bin, but 240K RAM disk + 360K just makes it (barely), leaving the second floppy for user files. 6) No swapping. Ever try swapping to a floppy? I did. The first version of MINIX did just that. To make a long story short, it didn't work real good. It was a lot of code, so I threw it away. 7) 640K limit. The 8088 arhcitecture does not encourage use of memory above 640K, but a RAM disk driver for extra memory shouldn't be too hard. 8) Booting from hard disk. This fix has been posted, but I don't like it. First of all, you lose hard/floppy compatibility. Second, if your hard disk ever gets flakey, you can't do anything. 9) FSCK should be renamed "Fragment,Crash,Collate,Kill". You are not supposed to fsck device 0, only 1-4. Device 0 is the raw disk. MINIX is being ported to the 68000 (Atari ST), but again we are assuming that some users (probably most users) have floppy only, and the system will be designed for that. Andy Tanenbaum (ast@cs.vu.nl)
mmason@psu-cs.UUCP (06/11/87)
In article <114@jc3b21.UUCP> you write: >I am not trying to insult Mr. Tanenbaum and MINIX. I think MINIX is the ... etc. I won't argue with this, but: >(1) the C compiler and MINIX upchucks floating point numbers at run time. > the documentation coyly warns of this. God, how do you write any kind > of applications even for fun only without real numbers?? HELP!! I'm using MSC as a cross-compiling environment (the compiler that came with MINIX is a joke). With it I'm running graphics applications with floating point. It's simply a matter of using the libraries that came with Microsoft C. >(2) The boot operation leaves me wondering why a hard disk was not used > right off the top. Who would ever try to run UNIX on floppies?? I normally boot on DOS, and use the MINIX boot diskette to run MINIX. There was a trivial change to get it to read the ramdisk from the hard disk. It now boots MINIX in under 30 seconds (not at all bad for a UN*X system). >(3) There is no multi-user capabilities provided as I read it. I only > need one for testing purposes. I know the processor is brain dead and > that is the basic problem. Has anyone written a /dev/tty02 or higher > that works?? I just picked one up from the net. Haven't tried it yet. >(4) The / directory is a flying joke. This must be because of the need to > use 2 floppy drives instead of a hard disk. If you accidentally copy > a large directory into slash / you are up for some entertainment. No comment, except that I like the idea. >(5) The ram disk uses up too much memory that could be used by other tasks. > Can this be killed and sent to disk where it belongs?? Easily done (I've got diffs from the net). My solution will be to add expansion memory to use for the root filesystem. >(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say? Exercize for the reader? More memory is probably the easiest solution. >(7) MINIX does not appear to work with more than 640k of ram. Can this be > expanded?? It shouldn't be difficult. >(8) This is a rephrase of #2 above: can you boot directly to hard disk > without any floppys? I can get /dev/hd0 to work as /dev/hd0 but I > can not boot directly to /dev/hd0. I've collected two different set of diffs to do just this. >(9) FSCK should be renamed "Fragment,Crash,Collate,Kill". If you use an > entire hard disk partition for MINIX which works fine by the way, FSCK > will screw it up because FSCK is expecting partitions 1-4 and not > partition 0.. If I ignore running FSCK I have no problems. You shouldn't be using /dev/hd0 for a filesystem (this is mentioned in the readme file in /user/doc). This isn't just MINIX, but BSD 4.X and XENIX also use the zeroth partition for the entire drive, which includes bad block tables, etc. In the case of MINIX, it includes the partition table. I've used partitions 1 and 2 with no trouble from FSCK. MINIX differs from OS9 and uniflex in that it is (for the most part) system call compatible with V7 UNIX. This implies a greater degree of compatibility with existing software and eliminates the need for the software developer to learn a new (and probably transient) system interface. UNIX is fast becomming a standard. From what I've seen of MINIX it would be possible to run it in a production environment (I'm planning to run OS project classes on it), but it would probably take an experienced UNIX systems programmer to prepare and maintain it for such purposes. But don't forget that MINIX is extremely young at this point. There are many people contributing useful additions and fixes to it, and many more people banging away at it. I expect to see it mature into a user- managable OS in a relatively short time (3-5 years). Mark Mason ...!tektronix!psu-cs!mmason
cmf@cisunx.UUCP (06/11/87)
In article <191@uoregon.UUCP>, dboyes@uoregon.UUCP (David Boyes) writes:
* >(4) The / directory is a flying joke. This must be because of the need to
* > use 2 floppy drives instead of a hard disk. If you accidentally copy
* > a large directory into slash / you are up for some entertainment.
*
* Agreed. However, Minix is very like Sys 7 Unix on the old PDP-11's, and
* they handled / exactly like Minix does. Blame this one on the model, not
* Minix. 2.9 BSD has this problem, too.
I'm not sure exactly what the problem with "/" is. The 7th edition (there never
has been a "Sys 7") didn't handle "/" significantly differently from any
Unix running today, including System V and 4.x BSD.
* >(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say?
*
* Sys 7 didn't swap either -- this ain't vmunix. Plus, you have to take
* into consideration hardware constraints -- you can't swap to floppies --
* you yourself complained about how slow floppies are.
* (miscellaneous ravings deleted)
Version 7 (aka Seventh Edition, but NOT Sys 7 -- see above) most certainly
did swap. You're confusing swapping with demand paging, which wasn't
implemented until 3.0 BSD came along. Incidentally, if Version 7 didn't
swap, how did anybody get anything done on a PDP-11 with a 256Kbyte physical
address space?
I can understand not being familiar with the systems of the past, but to
make such obviously wrong statements about them is only creating more
confusion. The Seventh Edition manuals were available in book stores
until they were replaced with System V Release 3 manuals. Maybe your
book store still has a copy. Check it out.
Carl Fongheiser
Systems Analyst/Programmer
University of Pittsburgh
...!pitt!cisunx!cmf
cmf@pittvms.BITNETpeter@sugar.UUCP (06/12/87)
> >(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say? > > Sys 7 didn't swap either -- this ain't vmunix. Plus, you have to take By Sys7 do you mean Version 7? If so, I'd like to correct you. Version 7, version 6, and version 5 all swapped. I know, because I've used all three. Perhaps you're thinking of paging. By the way, I have always argued that Version 7 was UNIX at its best. Thank you, Andrew Tannenbaum. You have renewed my faith in human nature. Or something to that effect.
vizard@dartvax.UUCP (Todd Krein) (06/15/87)
In article <1205@botter.cs.vu.nl>, ast@cs.vu.nl (Andy Tanenbaum) writes: > > Your specific comments: > > 1) No floats. I agree, they would be nice, but I haven't personally used > a number > 32767 in years. Is anyone working on floats? > I really didn't want to mention it before the whole thing was done, but I'm really feed up with people saying "I want ----", "Andy didn't give me ----", etc. Yes, I too was disapointed that Minix didn't have floating point, so I got a start from Dr. Tanenbaum and began. Several sections are done, more partially complete. Work goes slow, as I'm also trying to write my M.E. thesis and continue research, as my stipend is my only support. I do not want a box full of "Oh, send me it when it works" or such crap. When it's done and beta-tested, I'll post it. I would like, if anyone else is REALLY interested and not just wasting my time, some help. If people would be so kind as to develope self-testing floating point programs (a test-suite if you will), that would be the most helpfull. I'm sorry for the snide tone of writing ( ;-> ), and I'm sure I'll be sorry about mentioning the project before it's done, but perhaps this will kill some of the time wasting, lazy-*ssed crud being posted. Todd Krein Thayer School of Engineering Hanover, NH 03755 (603) 646-3866 vizard@dartvax (Ah... I feel so much better now...)
philip@axis.fr (Philip Peake) (06/24/87)
In article <191@uoregon.UUCP>, dboyes@uoregon.UUCP (David Boyes) writes: > In article <114@jc3b21.UUCP> gordon@jc3b21.UUCP (R. Gordon Price) writes: > > >(6) NO SWAPPING IMPLEMENTED IS A HORROR!! What can I say? > > Sys 7 didn't swap either -- this ain't vmunix. Plus, you have to take I don't want too detract from you article, with which I agree 99.9%, but, when you refer to Sys 7 I suppose that you mean Version 7 UNIX - and this definately DOES swap. Philip