[comp.os.minix] Commonly Asked Minix Questions Apr 18 1991

overby@plains.NoDak.edu (Glen Overby) (05/01/91)

[  If you have questions and answers to contribute, please send them to me, ]
[  overby@plains.nodak.edu                                                  ]

[ no 'diff' this time, either.  No changes..                                ]

                 Commonly Asked Questions on Comp.Os.MINIX

The venerable Minix Information Sheet never seems to  satisfy  the  endless
questions  asked  on comp.os.minix.  It's prose style probably doesn't lend
itself to the quick hand-holding that some seek.

As a result, I have decided to create this "Question-Answer" format compan-
ion  to  hopefully  fill  the gap.  It's an impossible task, but maybe this
will help.

In creating this, I have attempted to recall the Great Questions (and their
answers)  as  well  as  the Great Discussions from the net.  Many thanks to
those two people who have contributed to this document.

Several things to remember when you ask questions on the net:

Supply enough information for people to actually  help  you.   Things  like
what  Minix  version, your hardware configuration, and so-on are almost al-
ways necessarey to not have to take shots in the dark.  If you  are  reluc-
tant to tell any or all of this, don't expect a good answer.


1.  WHERE CAN I GET MINIX?
     Minix is sold by Prentice-Hall, Inc. and  their  authorized  distribu-
     tors.  They hold the Copyright on Minix, and sell it for profit (or at
     least we assume they make a profit on it).

                     IT IS NOT AVAILABLE FOR ANONYMOUS FTP!

2.  WHAT VERSIONS OF MINIX EXIST?
     The most current version is 1.5.10, known simply as "1.5" if  you  buy
     it  from  Prentice-Hall.   Upgrade "diffs" have been posted to the net
     over the past several months; consult an archive site  listed  in  the
     Info Sheet to find that.  Prentice-Hall has been shipping ALL versions
     of Minix 1.5 for several months.

3.  BUT I'VE HEARD OF THIS A NEWER VERSION, 1.6.15.
     Yes, that sort of exists; it is a mid-development beta release for the
     PC (only) released to beta-testers.

4.  HOW DOES PDP 11/44 MEMORY MANAGEMENT WORK?
     This was the first big off-the-topic discussion on the group, and it's
     still  not  an  appropriate topic, so if you are still intrigued about
     pdp-11 memory management, consult the DEC processor handbooks, or some
     harmless newsgroup like alt.dev.null.

5.  PLEASE SUBSCRBE ME TO THE MAILING LIST
     why ask 26,000 people to do that, when there is one person who can  do
     it, and you can ask a computer to do it for you.

     If you are on bitnet or arpanet, you can  get  this  newsgroup  via  a
     mailing  list, info-minix.  To subcribe to the list, send a message to
     listserv@vm1.nodak.edu (internet) or listserv@ndsuvm1 (bitnet) saying:

               signup minix-l your_full_name

     If you have  trouble,  contact  the  list  maintainer  at  info-minix-
     request@udel.edu.

6.  PLEASE UNSUBSCRIBE ME FROM THE MAILING LIST
     Use the same procedure as for subscribing, but use  "unsubscribe"  in-
     stead of "signup".

7.  WHAT IS THE ROOT PASSWORD?
     It's in the book, on pages 373 (login "ast") and 380  (login  "root").
     If you didn't buy the book, that's only the start of your problems.

8.  MINIX DOESN'T WORK WITH MY HARD DISK.
     There are many potential sources of this.  Several are:

     You are running an RLL controler.  You must change "NR_SECTORS" in the
     configuration  file,  <minix/config.h>  from 17 (standard for MFM con-
     trollers) to 25 (Adaptect controlers) or 26 (Western Digital and  oth-
     ers).

9.  IS THERE A SCSI DRIVER FOR MINIX?
     All SCSI controlers work differently, from the primitive Seagate ST01,
     to the smarter Always IN-2000, and Adaptec with it's own on-board CPU.

     Magnus Doell has released his driver  for  the  ST-02,  and  there  is
     another one for an Adaptec controler.  The ROM wini driver should also
     run most SCSI controlers but you loose protected mode capability.

10.  THE SINGLE THREADED FILESYSTEM IS A REAL BOTTLENCK.
     True.  It's only noticeable when you  are  running  massive  bacground
     processes, or putting multiple users on your computer.

     You've got the source.  Fix it.

11.  IS THERE A 386 MINIX?
     Minix 1.5.10/PC runs on 80286 and 80386 systems using 80286  protected
     mode  (so  all  your memory is used for programs, rather than as bank-
     switched memory "windows" or a big RAM disk).  There is an  experimen-
     tal   32-bit   kernel   from   Bruce  Evans.   It  is  available  from
     sirius.ucs.adelaide.edu.au in Australia and as plains.nodak.edu.

12.  I HAVE AN OLD VERSION OF MINIX. HOW CAN I UPGRADE?
     You need to get an upgrade kit from one of the archive sites; see  the
     Minix  Information  Sheet  for  a  (supposedly) complete list of sites
     which archive Minix-related bits.

     Also, read the Upgrading Tutorial -- it was ment to help.

13.  WHAT SHELLS EXIST FOR MINIX?
     sh:     Your typical Bourne shell. Comes with distribution Minix
     clam:   Tcsh-like shell, runs under Minix & real Unix's. Available
             from ftp sites sirius, ccadfa, plains & others
     ksh:    Korn shell, ported to Minix. Diffs for Minix on plains.
     marvin: A kid's shell. Posted months ago in comp.os.minix.
     emacs:  Does this count as a shell? Works only under 68K-Minix's
             and perhaps 386-Minix.

14.  IS THERE X-WINDOWS FOR MINIX?
     No, there is not.  It would be difficult if not impossible  (that  was
     ment as a challenge!) to put X on Minix because X is huge.  Unless you
     have many megabytes of memory, it would be impossible to run X clients
     and  servers  on  one  machine.  It will also certainly require 32-bit
     mode operation.

15.  WHY CAN'T MY PC CAN'T BOOT PC-MINIX FROM 1.44MB FLOPPY DISKS ?
     There's a couple of reasons for this.  First, straight out of the box,
     MINIX  doesn't  plan on dealing with 1.44Mb floppy disks.  The entries
     in /dev should be set up specifically for your machine,  so  pick  out
     the correct entries here:
          mknod /dev/fd0-dsdd5in b 2  4 360               # Drive A, 360K 5.25"
          mknod /dev/fd0-dshd5in b 2  8 1200              # Drive A, 1.2M 5.25"
          mknod /dev/fd0-dsdd3in b 2 16 720               # Drive A, 720K 3.5"
          mknod /dev/fd0-dshd3in b 2 28 1440              # Drive A, 1.44M 3.5"
                     ^^^             ^^
     Change 'fd0' to 'fd1' and add 1 to the minor device number  to  create
     an entry for floppy drive B.  It may be a good idea to link the gener-
     ic  floppy  disk  entries  (/dev/fd0  and  /dev/fd1)  to  the   proper
     /dev/fd0-ds{whatever}  entries for your machine, so that programs like
     dosread continue to work.

     Second reason your PC won't boot from 1.44Mb floppy disks, even though
     you've  fixed  up  the  floppy  disk  device entries: tools/bootblok.s
     doesn't know about 1.44M disks, so it blindly loads the boot image in-
     correctly  and  then tries to execute it.  Get Guy Helmer's bootblok.s
     from an archive site, or get shoelace.

16.  WHAT'S WRONG WITH 'ps'?
     You   need   to   have   a   copy   of   the   compiled   kernel    in
     /usr/src/kernel/kernel  for ps to read the namelist out of.  Note that
     this MUST be the SAME kernel that is booted.

17.  HOW IS THE FORK(2) SYSTEM  CALL  IMPLEMENTED  ON  THE  68K  PROCESSORS
     WITHOUT A MEMORY MANAGEMENT UNIT?
     This is done by shadowing. This is copying the memory around  as  long
     as  both  child  and parent proces do exist.  Although this seems very
     expensive, it is not because most processes exec(2) almost immediately
     after  the fork(). But most terminal emulators who fork() en keep run-
     ning loose.

18.  WHY IS KERMIT SO ABSURDLY SLOW UNDER MINIX-68k?
     See the above question.  Kermit forks so that one process  listens  to
     the  serial  port  and  writes  to  the  screen, and the other process
     listens to the keyboard and writes to  the  serial  port.   Since  the
     second  process  never  "exec's",  the  two  processes are continually
     swapped in and out of one memory slot.

19.  IS THERE ALSO A 64K+64K LIMIT FOR MINIX 68K & MINIX 386?
     For minix 68k, there isn't. For minix 386 there isn't provided you use
     the proper compiler (This means no ACK)

20.  DOES MINIX HAVE BERKELY JOB CONTROL?
     No. Nor does it have its associated signals like SIGSTOP, SIGCONT etc.

21.  DOES MINIX SUPPORT TCP/IP AND NFS
     No. TCP/IP does exist as an experimental package.  NFS is a dream  for
     many ;-)

22.  WHY CAN'T I RECOMPILE KERMIT OR ELLE ON PC-MINIX 1.5?
     You can't assemble Kermit or elle on a PC using Minix 1.5 or  earlier;
     asld  reports an "out of space" error, which means it ran out of space
     in the output object file.  That is why the  binaries  are  (certainly
     were) on the P-H distribution.  Those binaries were compiled by a dif-
     ferent, more efficient compiler.




















--
                Glen Overby     <overby@plains.nodak.edu>
        uunet!plains!overby (UUCP)  overby@plains (Bitnet)

overby@plains.NoDak.edu (Glen Overby) (06/19/91)

[  If you have questions and answers to contribute, please send them to me, ]
[  overby@plains.nodak.edu                                                  ]

                 Commonly Asked Questions on Comp.Os.MINIX

The venerable Minix Information Sheet never seems to  satisfy  the  endless
questions  asked  on comp.os.minix.  It's prose style probably doesn't lend
itself to the quick hand-holding that some seek.

As a result, I have decided to create this "Question-Answer" format compan-
ion  to  hopefully  fill  the gap.  It's an impossible task, but maybe this
will help.

In creating this, I have attempted to recall the Great Questions (and their
answers)  as  well  as  the Great Discussions from the net.  Many thanks to
those two people who have contributed to this document.

Several things to remember when you ask questions on the net:

Supply enough information for people to actually  help  you.   Things  like
what  Minix  version, your hardware configuration, and so-on are almost al-
ways necessarey to not have to take shots in the dark.  If you  are  reluc-
tant to tell any or all of this, don't expect a good answer.


1.  WHERE CAN I GET MINIX?
     Minix is sold by Prentice-Hall, Inc. and  their  authorized  distribu-
     tors.  They hold the Copyright on Minix, and sell it for profit (or at
     least we assume they make a profit on it).

                     IT IS NOT AVAILABLE FOR ANONYMOUS FTP!

2.  WHAT VERSIONS OF MINIX EXIST?
     The most current version is 1.5.10, known simply as "1.5" if  you  buy
     it  from  Prentice-Hall.   Upgrade "diffs" have been posted to the net
     over the past several months; consult an archive site  listed  in  the
     Info Sheet to find that.  Prentice-Hall has been shipping ALL versions
     of Minix 1.5 for several months.

3.  BUT I'VE HEARD OF THIS A NEWER VERSION, 1.6.15.
     Yes, that sort of exists; it is a mid-development beta release for the
     PC (only) released to beta-testers.

4.  HOW DOES PDP 11/44 MEMORY MANAGEMENT WORK?
     This was the first big off-the-topic discussion on the group, and it's
     still  not  an  appropriate topic, so if you are still intrigued about
     pdp-11 memory management, consult the DEC processor handbooks, or some
     harmless newsgroup like alt.dev.null.

5.  PLEASE SUBSCRBE ME TO THE MAILING LIST
     why ask 26,000 people to do that, when there is one person who can  do
     it, and you can ask a computer to do it for you.

     If you are on bitnet or arpanet, you can  get  this  newsgroup  via  a
     mailing  list, info-minix.  To subcribe to the list, send a message to
     listserv@vm1.nodak.edu (internet) or listserv@ndsuvm1 (bitnet) saying:

               signup minix-l your_full_name

     If you have  trouble,  contact  the  list  maintainer  at  info-minix-
     request@udel.edu.

6.  PLEASE UNSUBSCRIBE ME FROM THE MAILING LIST
     Use the same procedure as for subscribing, but use  "unsubscribe"  in-
     stead of "signup".

7.  WHAT IS THE ROOT PASSWORD?
     It's in the book, on pages 373 (login "ast") and 380  (login  "root").
     If you didn't buy the book, that's only the start of your problems.

8.  MINIX DOESN'T WORK WITH MY HARD DISK.
     There are many potential sources of this.  Several are:

     You are running an RLL controler.  You must change "NR_SECTORS" in the
     configuration  file,  <minix/config.h>  from 17 (standard for MFM con-
     trollers) to 25 (Adaptect controlers) or 26 (Western Digital and  oth-
     ers).

9.  IS THERE A SCSI DRIVER FOR MINIX?
     All SCSI controlers work differently, from the primitive Seagate ST01,
     to the smarter Always IN-2000, and Adaptec with it's own on-board CPU.

     Magnus Doell has released his driver  for  the  ST-02,  and  there  is
     another one for an Adaptec controler.  The ROM wini driver should also
     run most SCSI controlers but you loose protected mode capability.

10.  THE SINGLE THREADED FILESYSTEM IS A REAL BOTTLENCK.
     True.  It's only noticeable when you  are  running  massive  bacground
     processes, or putting multiple users on your computer.

     You've got the source.  Fix it.

11.  IS THERE A 386 MINIX?
     Minix 1.5.10/PC runs on 80286 and 80386 systems using 80286  protected
     mode  (so  all  your memory is used for programs, rather than as bank-
     switched memory "windows" or a big RAM disk).  There is an  experimen-
     tal   32-bit   kernel   from   Bruce  Evans.   It  is  available  from
     sirius.ucs.adelaide.edu.au in Australia and as plains.nodak.edu.

12.  I HAVE AN OLD VERSION OF MINIX. HOW CAN I UPGRADE?
     You need to get an upgrade kit from one of the archive sites; see  the
     Minix  Information  Sheet  for  a  (supposedly) complete list of sites
     which archive Minix-related bits.

     Also, read the Upgrading Tutorial -- it was ment to help.

13.  WHAT SHELLS EXIST FOR MINIX?
     sh:     Your typical Bourne shell. Comes with distribution Minix
     clam:   Tcsh-like shell, runs under Minix & real Unix's. Available
             from ftp sites sirius, ccadfa, plains & others
     ksh:    Korn shell, ported to Minix. Diffs for Minix on plains.
     marvin: A kid's shell. Posted months ago in comp.os.minix.
     emacs:  Does this count as a shell? Works only under 68K-Minix's
             and perhaps 386-Minix.

14.  IS THERE X-WINDOWS FOR MINIX?
     No, there is not.  It would be difficult if not impossible  (that  was
     ment as a challenge!) to put X on Minix because X is huge.  Unless you
     have many megabytes of memory, it would be impossible to run X clients
     and  servers  on  one  machine.  It will also certainly require 32-bit
     mode operation.

15.  WHY CAN'T MY PC CAN'T BOOT PC-MINIX FROM 1.44MB FLOPPY DISKS ?
     There's a couple of reasons for this.  First, straight out of the box,
     MINIX  doesn't  plan on dealing with 1.44Mb floppy disks.  The entries
     in /dev should be set up specifically for your machine,  so  pick  out
     the correct entries here:
          mknod /dev/fd0-dsdd5in b 2  4 360               # Drive A, 360K 5.25"
          mknod /dev/fd0-dshd5in b 2  8 1200              # Drive A, 1.2M 5.25"
          mknod /dev/fd0-dsdd3in b 2 16 720               # Drive A, 720K 3.5"
          mknod /dev/fd0-dshd3in b 2 28 1440              # Drive A, 1.44M 3.5"
                     ^^^             ^^
     Change 'fd0' to 'fd1' and add 1 to the minor device number  to  create
     an entry for floppy drive B.  It may be a good idea to link the gener-
     ic  floppy  disk  entries  (/dev/fd0  and  /dev/fd1)  to  the   proper
     /dev/fd0-ds{whatever}  entries for your machine, so that programs like
     dosread continue to work.

     Second reason your PC won't boot from 1.44Mb floppy disks, even though
     you've  fixed  up  the  floppy  disk  device entries: tools/bootblok.s
     doesn't know about 1.44M disks, so it blindly loads the boot image in-
     correctly  and  then tries to execute it.  Get Guy Helmer's bootblok.s
     from an archive site, or get shoelace.

16.  WHAT'S WRONG WITH 'ps'?
     You   need   to   have   a   copy   of   the   compiled   kernel    in
     /usr/src/kernel/kernel  for ps to read the namelist out of.  Note that
     this MUST be the SAME kernel that is booted.

17.  HOW IS THE FORK(2) SYSTEM  CALL  IMPLEMENTED  ON  THE  68K  PROCESSORS
     WITHOUT A MEMORY MANAGEMENT UNIT?
     This is done by shadowing. This is copying the memory around  as  long
     as  both  child  and parent proces do exist.  Although this seems very
     expensive, it is not because most processes exec(2) almost immediately
     after  the fork(). But most terminal emulators who fork() en keep run-
     ning loose.

18.  WHY IS KERMIT SO ABSURDLY SLOW UNDER MINIX-68k?
     See the above question.  Kermit forks so that one process  listens  to
     the  serial  port  and  writes  to  the  screen, and the other process
     listens to the keyboard and writes to  the  serial  port.   Since  the
     second  process  never  "exec's",  the  two  processes are continually
     swapped in and out of one memory slot.

19.  IS THERE ALSO A 64K+64K LIMIT FOR MINIX 68K & MINIX 386?
     For minix 68k, there isn't. For minix 386 there isn't provided you use
     the proper compiler (This means no ACK)

20.  DOES MINIX HAVE BERKELY JOB CONTROL?
     No. Nor does it have its associated signals like SIGSTOP, SIGCONT etc.

21.  DOES MINIX SUPPORT TCP/IP AND NFS
     No. TCP/IP does exist as an experimental package.  NFS is a dream  for
     many ;-)

22.  WHY CAN'T I RECOMPILE KERMIT OR ELLE ON PC-MINIX 1.5?
     You can't assemble Kermit or elle on a PC using Minix 1.5 or  earlier;
     asld  reports an "out of space" error, which means it ran out of space
     in the output object file.  That is why the  binaries  are  (certainly
     were) on the P-H distribution.  Those binaries were compiled by a dif-
     ferent, more efficient compiler.

23.  WHY AREN'T THE MANUALS ONLINE? WHERE CAN I GET THE MANUALS?
     The  online   manuals   are   available   via   anonymous   ftp   from
     ccadfa.cc.adfa.oz.au  [131.236.1.2] in the file pub/minix/mantar.Z. To
     extract the manuals, ftp the file binary-wise, uncompress it  and  ex-
     tract  using  tar when you are in your /usr/man directory. Each manual
     is in a separate file, and to use the distribution 1.5 man(1) you will
     need  to  read  the  source  to man(1) to see how to create the single
     manual file.

     Alternatively, the source to a more Unix-like man(1) is  available  on
     ccadfa  in  the  file  pub/minix/mansrc.Z.  To  extract  the code, ftp
     binary-wise, uncompress and unshar. Before compiling the code,  modify
     the header file to reflect your system setup. Compile the code. If you
     are using less(1) as a pager,  you  will  need  to  modify  main.c  in
     nroff(1); instructions are included in mansrc.Z

24.  WHAT IS THE DIFFERENCE BETWEEN THE 80386 AND THE 386sx?
     There is no difference between 386sx/386dx except for the bus  (24-bit
     addresses and 16-bit data).
-- 
		Glen Overby	<overby@plains.nodak.edu>
	uunet!plains!overby (UUCP)  overby@plains (Bitnet)