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)